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242 Cards in this Set

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What are the functions of skin?
-The skin provides a protective barrier against the environment.
-The skin protects the body against the invasion of bacteria and other foreign material.
-The skin has complicated endocrine and exocrine function.
-The skin is important in fluid and electrolyte balance.
-The skin controls body temperature by the process of either vasoconstriction and vasodilatation or by the evaporation of perspiration.
-The skin protects against penetration of ultraviolet light radiation.
-The skin processes antigenic substances presented to it.
What are the 3 layers of the skin?
From the inside out the layers are:
-Hypodermis or subcutaneous tissue
-Dermis
-Epidermis
What are the characteristics of the hypodermis?
-Deepest layer of skin
-Gives the skin its pliability
-Involved in thermal insulation, nutritional reserves and cushioning
-Contains nerves associated with light and heavy pressure
How does the hypodermis relate to adipose tissue?
-Serves as a receptacle for the formation and storage of fat
-Supports blood vessels and nerves that pass from the tissues beneath to the dermis above
-Largest volume of adipose tissue in the body
-Thickness of fat tissue varies from one area of the body to another
What are the characteristics of the dermis?
-40 times thicker than epidermis
-Richly vascular connective tissue of the skin
-Supports and separates the epidermis from the hypodermis
-Contains elastin, collagen, and recticulin fibers which provide resilience, strength, stability, and elasticity to the skin
-Contain nerves that provide sensation of touch, pain, and temperature
What does the dermis contain?
-Contains blood vessels,
-Contains hair follicles
-Also contains Pilosebaceous, apocrine and eccrine structures
Where are sebaceous glands found?
-They are located next to the hair follicle.
-High number on face, scalp, and upper trunk.
What is the function of sebum?
-Sebum retards moisture evaporation from skin and is probably important in skin hydration and lubrication
-Important to the pathogenesis of acne
What are the characteristics of eccrine glands?
-Open to the surface of the skin rather than being associated with the hair follicle
-Involved in thermoregulation
-Secrete relatively hypotonic fluid that eventually evaporates and cools the skin
-Sweat is mainly water
What are the characteristics of apocrine glands?
-Located in axilla and in genital area
-Secrete continuously or in response to psychological stimulus
-Of no direct use in humans today
-Have no intrinsic odor of secretion but odor is quickly produced when sweat from these glands is delivered to skin surface and acted upon by skin bacteria
What is the thickness of the epidermis?
About 1mm.
What types of cells are contained in the epidermis?
-Keratinocytes or keratin forming cells
-Melanocytes
-Langerhans’ cells
What are the layers of the epidermis?
Epidermis consists of 4 or 5 layers:
-Stratum germinativum (basal cell layer)
-Stratum spinosum- squamous cell or prickle cell layer
-Stratum granulosum- granular cell layer
-Stratum lucidum
-Stratum corneum- Horny cell layer
Where are melanocytes found?
In the basal cell layer.
What are the functions of the basal cell layer?
-Basal cells can be considered to be skin “stem cells”
-Undifferentiated proliferating cells
Daughter cells from the basal cell layer migrate upward and begin the process of differentiation
-In normal skin, cell division does not take place above the basal cell layer
What are the functions of melanocytes?
-Account for 1% of the cells of the epidermis
-Pigment producing dendritic cells
-Pigment is melanin
-Responsible for skin color tones of races
-Light skinned races and dark skin races have same number of melanocytes, difference is in amount of melanin in the cells
-Protects body from UV radiation
What type of cells make up most of the epidermis?
Keratinocytes.
What are the characteristics of the stratum spinosum?
-Lies above the basal cell layer, composed of keratinocytes
-Langerhan's cells also in stratum spinosum
Keratin contains a large amount of what element?
Sulfur.
What are the characteristics of Langerhan's cells.
-Account for 3-5% of the cells in the epidermis
-Dendritic cells that resemble melanocytes but do not produce pigment
-Have proprieties of the monocyte/macrophage cell
-Involved in immune response and may trigger the inflammatory response associated with allergic contact dermatitis
-Destroyed by UV radiation
May be important in pathogenesis of cutaneous malignancies
What are the characteristics of the stratum corneum?
-Outermost layer of the epidermis
-Are large, flat and plate-like
-Are dead and filled with keratin
-Stratum corneum layer provides semi-impenetrable barrier
-Major physical barrier of the skin
How long is the epidermal cell cycle?
It takes 2 weeks for cells to migrate from the basal cell layer to the top of the stratum granulosum.
What is a macule?
-A flat, circumscribed area that is simply a change in the color of the skin. It is 1.0cm or less than in diameter
-Not palpable and can’t feel them
-Can be brown, blue, red, or hypopigmented
-Examples are freckles, vitiligo, pigmentation
What is a papule?
-A solid lump 1.0cm or less in diameter
-Easy to palpate
-Warts
What is a nodule?
-A papule that is spherically enlarged in three dimensions length, height and width
-Larger than 1.0cm in diameter
-May involve the epidermis, dermis or hypodermis
-Can be seen on or can be palpated within the skin
What is a tumor?
-A large nodule of greater than 2cm in size
-May not be clearly demarcated
-Maybe deep in dermis
-Tumor usually refers to a malignant lesion
What is a plaque?
-This lesion is solid, elevated, flat-topped, and plateau-like.
-Covers a fairly large area.
-May arise from papules that join together.
-Diseases in which this type of lesion predominates include psoriasis and chronic atopic dermatitis
What is a vesicle?
-Small blisters 1.0cm or less in diameter,
-Are filled with clear serous fluid.
-Herpes simplex and chicken pox
What is a wheal?
-Elevated, irregular-shaped papule
-Substance of lesions consists of interstitial non-loculated fluid
-Are transient lesions lasting less than 24 hours
-Also called hives
-Usually caused by an allergic reaction.
What is a pustule?
-Elevated lesion similar to a vesicle but filled with pus rather than serous fluid.
-Are white or yellow-white in color
-Sometimes pustules do not necessarily mean the presence of an infection
What is Telangiectasia?
-Fine, irregular red lines
-Caused by capillary dilation
-Common on the nose, especially in alcoholics
What are petechiae?
-Red-purple non-blanchable discolorations of the skin
-Less than 0.5cm in diameter
-Can be caused by bleeding into the skin
-Can be caused by inflammatory damage to the blood vessels
What are purpura?
-Red-purple non-blanchable discolorations of the skin
-Large petechiae
-Larger than 0.5cm deposit of blood or blood pigment in the skin
What are ecchymoses?
-Red-purple non-blanchable discolorations of the skin
-Very large petechiae and can be of variable size
-Deposit of blood or blood pigment in the skin
-Caused by vascular wall destruction
What is an erosion?
-Loss of part of the epidermis.
-May follow the rupture of vesicle or bulla
What is an ulcer?
-Loss of both epidermis and dermis
-Deeper into the skin than an erosion
-Heal with scarring
What is an ulcer?
-Linear crack in the epidermis that may extend into the dermis.
What is atrophy?
-Thinning of the skin surface and loss of skin markings.
-Skin becomes paper-like and translucent
What are keloids?
-Hypertropic scars
-Form beyond the borders of the original injury
-More common in Asian and African-Americans than Caucasians
What is excoriation?
-Superficial linear abrasions of the skin
-Usually caused by scratching
What is lichenification?
-A diffuse area of thickening and scaling with resultant increase in skin lines and markings
-Usually caused by chronic rubbing
-Surface looks like a washboard
What is a spider anginoma? What are common causes of spider anginomas?
-Red central body with radiating central legs
-Blanch with pressure to the central body
-Caused by severe liver disease and vitamin B deficiency
What is a papulosquamos reaction pattern?
-Rash in which the primary lesion consists of primarily of papules with overlying scale
-In certain instances a macule with overlying scale can also be described as having a papulosquamous reaction pattern
What are two diseases associated with a papulosquamos reaction pattern?
Psoriasis and pityriasis rosa are two diseases associated with a papulosquamous reaction pattern.
What is the hallmark characteristic of an eczematous reaction pattern?
Lichenification.
What is a vesicobullous reaction pattern?
-Consists of blisters
-At an early stage maybe macules or papules that later become fluid filled
What does a vascular reaction pattern refer to?
Redness (erythema) and/or edema as a result of vasodilation.
What are red lesions related to?
Blood flow or presence of inflammation.
What are brown, black, or blue lesions related to?
The presence of either melanin or heme.
What are white lesions related to?
The absence of melanin.
What are yellow lesions related to?
The presence of abnormal chemicals, or lipids and proteins.
What is the difference in margination between papulosquamous lesions and eczematous lesions?
Papulosquamous lesions are sharply marginated whereas eczematous lesions are diffusely marginated.
What are nummular lesions?
Nummular is used to describe sharply marginated, round lesions that are about the size of a large coin.
What are serpiginous lesions?
Serpiginous or snake-like lesions occur due to the melding of adjacent lesions until they reach the point of confluence.
What are characteristics of a psoriatic scale?
-Easily palpable, visible white, silver or gray flakes
-Very large flakes
What are the characteristics of a pityriasis type scale?
-Small flakes to small to be seen individually
-Hardly visible or palpable
-Scrape fingernail on skin revels a powdery, fine, white sale.
What are the characteristics of a lichen type scale?
-Slightly palpable roughness
-Scales are shiny and translucent
-Tightly adheres to the surface of the lesion
How does hydration relate to skin absorbtion of a drug?
-Normal water content of stratum corneum is 20%
-If water content is less than 20%, have decreased drug absorption
-If water content is more than 20% have increased drug absorption
What are the functions of astringents?
-Applied to skin or mucous membranes
-Coagulate protein, protect underlying tissue and decrease cell volume
-Cause vasoconstriction and reduce blood flow
-Lessen mucus and other secretions
-Drying sometimes helps relieve local irritation
What is urea used for?
-Available in 10 to 30% concentration
-Mildly keratolytic and increases water uptake in the straum corneum
-Binds with skin protein and improve skin elasticity
-Recommended for use on crusted tissue
-Better able to remove scales and crusts and re-hydrate skin
-Can cause stinging, burning and irritation
What are examples of good and bad topical anesthetics?
-Pramoxine and lidocaine are a good choices
-Avoid dibucaine and benzocaine
What is Icythyosis Vulgaris?
-Genetic disease usually identified in first 3 months of life
-Affects about 1% of the population
-Symptoms include dry and rough skin, accompanied by fine small white scales
-Tends to appear on arms and legs
-Classic fish scale appearance of skin
-May develop into a serious disease.
What is the goal of treatment of Icythyosis Vulgaris?
-Restore skin hydration
-Restore barrier function of skin if it has been lost
How does an emollient work?
--It works to soften the skin by leaving an oily film on skin and reduce water evaporation from skin
-Reestablishes integrity of the stratum corneum thus making the skin feel soft and smooth
What are humectants?
-Hygroscopic agents that are added to emollient bases
Glycerin, propylene glycol and phospholipids are examples
-Draw water into the stratum corneum
-Water may come from the atmosphere or the dermis
--> Humidity must be higher than 80% before water is drawn for the atmosphere
What are the mechanisms of action of topical corticosteriods?
-Corticosteroids enter cells and bind to glucocorticoid receptors
-Complex enters nucleus and binds specific sites on the DNA molecule
-Once bound, complex is able to stimulate or inhibit transcription of cells downstream from the binding location
-Decrease vascular permeability reducing dermal edema
-Decrease leukocyte penetration into skin
-Have anti-inflammatory antimitotic and immunosuppressive effects
What are the anti-inflammatory effects of topical corticosteriods?
-Reduces production of leukotrienes and prostaglandins which are inflammatory mediators
-Diminish chemotaxic response so that neutrophils and monocytes fail to accumulate at the site of inflammation
-There is local interference with macrophage secretion of elastase, collaginase and plasminotin. These are tissue enzymes which are hydrolytic in nature
-Corticosteroids also block the antigen-mediated released of histamine and may limit the response of target cells to the effects of histamine
What are the immune effects of topical corticosteriods?
-Interfere with several essential steps in the immune process
-Impede the passage of immune complexes across basement membranes
-Have no apparent effect on antibody or complement synthesis
-Directly suppress local T-lymphocyte activity by means of decreased macrophage recruitment
-Change in Langerhans’ cell markers that alter their antigen-presenting capabilities
-Interfere with the cutaneous activity of interleukins including IL-1 and IL-2 as well as prostaglandins
-Suppress lymphocyte proliferation
What are the anti-proliferative effects of topical corticosteroids?
-Retards DNA synthesis and therefore has an antimitotic effect on the basal cell layer
-Reduces fibroblastic activity in the dermis
What is the basis of classification of topical corticosteriods?
-Potency based upon the vasoconstrictor assay developed by Staughton and Mckenzie
-Measures the amount of skin blanching produced by a given corticosteroid
-Shows strong correlation between therapeutic efficacy and adverse effects
What are some class 1 topical corticosteriods?
halobetasol, clobetasol, betamethasone
What are some class 2-5 topical corticosteriods?
betamethasone, mometasone, triamcinolone
What are some class 6-7 topical corticosteriods?
fluocinolone, hydrocortisone, dexamethasone
When are class 1 topical corticosteriods used?
-Sometimes used as an alternative to systemic corticoid therapy when relatively small areas of the skin are involved
-Used on thick, less permeable tissues
-Used on chronic lesions of psoriasis
-High likelihood of adverse effects when using these preparations for prolonged periods of time
-Not to be used with occlusive dressings
When are class 2 topical corticosteriods used?
-Used for more severe cases of eczematous dermatitis
-May also be used for the treatment of psoriasis
-Only be used on the face or intertriginous areas for very brief periods of time (1 week or less)
When are low potency topical corticosteriods used?
-Can be used safely for relatively long term application
-Can be used with occlusion
-Safe for use on intertriginous and facial areas
-Used for the treatment young children
About what amount (grams) is a fingertip unit?
0.5 g
About how many FTU does it take to cover the face and neck?
2.5 FTU
About how many FTU does it take to cover both sides of 1 hand?
1 FTU
About how many FTU does it take to cover one arm?
3 FTU
What are some of the systemic effects of topical corticosteriods?
-growth retardation (children)
-iatrogenic cushing syndrome
-hypothalamic-pituitary-adrenal axis suppresion
What are some of the characteristics accompanying dermal atrophy caused by topical corticosteriods?
Telangiectasia, ecchymoses, striae, prominent underlying veins, and hypopigmented skin which bruises easily are characteristics of developing skin atrophy
What is steriod rosacea?
-Also called steroid acne
-Also called perioral dermatitis
-Occur as result of regular use of corticosteroids on the face
-Persistent erythema, papules, pustules, and telangiectasia
-Condition may flare when steroid is withdrawn
What are some indications for class 1 topical corticosteriods?
-Alopecia Aerata
-Bullous Pemphigoid
-Discoid Lupus Erythematous
-Severe Nummular Eczema
-Lichen Planus
-Severe Psoriasis
What are some eczematous type diseases?
-Atopic Dermatitis
-Infantile Eczema
-Hand eczema
-Contact Dermatitis
-Scabies
What are characteristics of an acute eczematous reaction?
-Acute eczematous rash is characterized by erythematous weeping vesicles and “juicy” papules
-Usually intensely itchy
What are characteristics of a subacute eczematous reaction?
-Red scale, erythema, and fissuring
-Itching is moderate
-Continuous scratching and rubbing converts this condition to a chronic process
What are characteristics of chronic eczema?
-Lichenification
-Thickened skin caused by chronic rubbing
-Exaggeration of normal skin markings
-Change in pigmentation
-Itching is intense
What is the distribution of eczema in infants?
-Cheeks, arms, legs, and groin
-Perioral area and scalp
-Around the ears
-On the body sparing the diaper area
What is the distribution of eczema in adults?
-Flexural involvement is common
-Hand dermatitis may be only manifestation
-Upper eyelid dermatitis is common
-Dermatitis on neck is common
-Dermatitis on face is less common
-Dermatitis on body can be diffuse and patchy
What are the goals of treating eczema?
-Dry acute weeping lesions
-Maintain skin hydration in subacute and chronic form of the disease
-Avoid or minimize factors that trigger or aggravate the disease
-Reduce itching
-One absolute goal must be obtained. Scratching must be stopped
-Therapy that fails to interrupt the itch scratch cycle will not lead to long-term clinical improvement
What is the role of antihistimines in treating eczematous disease?
-Topical antihistamines should be avoided
-Inhibit inflammatory mediators such as histamine
-Cause CNS depression which helps with sleep and reduces nighttime itching
-CNS depression may be most important effect of antihistamines
-Studies show tranquilizers reduce itching as well as antihistamines
-No place for non-sedating antihistamines
What are the cautions of using systemic corticosteriods in the treatment of eczematous disease?
-Therapy must be followed by a good topical program
-Failure to recognize this point will result in a rapid exacerbation of the disease
-One problem with this therapy is the possibility of precipitating a “flare” reaction.
-This can be avoided by tapering prednisone dosage
-Long term administration of oral corticosteroids have no place in the treatment of atopic dermatitis
What is the description of an acute lesion in contact dermatitis?
Well-demarcated, plaques of erythema and edema on which are superimposed closely spaced vesicles and punctate erosions exuding sebum and crusts
What is the description of a subacute lesion in contact dermatitis?
Plaques of mild erythema showing small, dry scales sometimes associated with small red firm papules
What is the description of a chronic lesion in contact dermatitis?
Plaques of lichenification with prominent skin lines and with satellite small firm excoriations and pigmentation or mild erythema.
What is appropriate treatment for irritant contact dermatitis?
-Use mildest soap possible to wash affected area
-When appropriate, no soap should be used
-Frequent application of thick and occlusive moisturizer is essential
-For irritant hand dermatitis, medium to high potency corticosteroid ointment applied twice a day for several weeks is usually effective in reducing erythema, itching, swelling and tenderness.
How does spreading of allergic contact dermatitis occur?
Spreading is believed to occur through hematogenous, immune-complex deposition is the skin
What are the two phases of allergic contact dermatitis?
-Sensitization phase
-Elicitation phase
What occurs during the sensitization phase of allergic contact dermatitis?
-A hapten penetrates into the epidermis and combines with epidermal protein to form an antigen
-Hapten-protein binding takes place near or on Langerhans’ cells
-Macrophages and T-cells in the epidermis process the antigen
-Sensitized T-cells are formed
What occurs during the elicitation phase of allergic contact dermatitis?
-Upon re-exposure to hapten-protein complex, sensitized T-cells release lymphokines
-Lymphokines recruit inflammatory cells that cause acute eczematous rash
-Time required to produce rash is usually 12-48 hours
-Varies from 8-120 hours
What are physician prescribed therapies for allergic contact dermatitis?
-More potent topical corticosteroids
-Oral corticosteroids such as prednisone
-For severe or generalized reactions a 3 week tapering course of oral corticosteroids such as prednisone may be used
-For allergic contact dermatitis, Medrol Dospak is not usually sufficient to achieve good clinical response
What are the characteristics of Rhus Dermatitis?
-Caused by poison ivy, oak, sumac
-The allergen on the plant is the oleoresin
-Rash appears within 12 hours to 2 days of exposure
-85% of patients will eventually develop sensitivity to the plant
-Rash lasts 10 days to 3 weeks
-Rash resolves completely without scarring
-Scratching can lead to secondary bacterial infections
What is the standard treatment for mild rhus dermatitis?
-Short, cool baths or showers are soothing for itching and swelling
-Cold but not icy wet compresses are highly effective during the acute blistered stage
-Calamine Lotion helps to control itching and dry wet, oozing lesions
-Medium potency topical corticosteroids are applied after the wet compresses
-Oral diphenhdramine or hydroxyzine helps to control itching and encourage sleep
How does the psoriasis skin cell cycle work?
-Epidermal cell cycle is accelerated
-Cell division occurs every 1.5 days
-Entire cell cycle takes placed in 3-4 days rather than 4 weeks
-Cells move so rapidly that they do not have time to differentiate and mature properly
-Stratum corneum is not fully keratinized
-Epidermal cells build up and become scaly
What is the theraputic wavelength of light for psoriasis?
UVB radiation
What types of drugs worsen psoriasis?
-Lithium
-Antimalarial agents
-β-blockers
-Systemic corticosteroids
What is guttae psoriasis?
-Guttate psoriasis is less common and characterized by many small teardrop-shaped lesions distributed evenly over whole body
-Scaling papules rather than plaque predominates
-Scaling papules develop within 1-2 weeks of a streptococcus or viral infection
-Lesions first appear on trunk and extremities
-May resolve spontaneously in 1-2 months
-More responsive to drug therapy than other forms of psoriasis
What is erythrodemic psoriasis?
-Rare, widespread disease
-Associated with massive protein and fluid loss and difficulty in maintaining body temperature
What are the goals of therapy for psoriasis?
-Decrease size and thickness of plaques
-Decrease epidermal proliferation and underlying dermal inflammation
-Relieve pruritus
-Induce remission and then use maintenance therapy
-Improve emotional well-being
What are some systemic therapies for psoriasis?
-Psoralens and UVA light (PUVA)
-Methotrexate
-Acitretin (Retinoid)
-Cyclosporin
How are topical corticosteriods useful in the treatment of psoriasis?
-Anti-mitotic and anti-inflammatory
-Helps to control itching
-Class II-V give best results
-Apply 1-2 times a day
-Ointment is base of choice
-Solutions are useful on scalp
-OTC hydrocortisone 1% products are virtually useless for treatment
How does coal tar work to treat psoriasis?
-Decreases epidermal mitosis and scale development
-Reduces sebum production and has anti-inflammatory properties
What are some adverse reactions associated with the use of coal tar?
-Skin irritation is common and therefore it is not recommended to apply over a large area
-Can cause acneiform rash or folliculitis
-Can cause contact dermatitis
-Can induce a phototoxic reaction
-Can stain the skin and hair
Carcinogenic? (in animals)
-May make inflammatory psoriasis worse
How do vitamin D3 derivatives work?
(Calciprotriene-Dovonex 0.005%)
-Bind to vitamin D3 receptors on the keratinocytes and regulate keratinocyte proliferation
-Inhibits T-Cell activity
-Indicated for mild to moderate plaque psoriasis
-Use twice daily on on plaque.
What kind of disease is seborrheic dermatitis?
Papulosquamous
What are some factors associated with seborrheic dermatitis?
-Vitamin B complex deficiency
-Zinc deficiency
-Food allergies
-Climate changes and low humidity
-Emotional and physical stress
-Overgrowth of normally present Pityrosporium ovale
What are the main differences between seborrheic dermatitis and dandruff?
-Incompletely keratinized cells make up 25-25% of cells in seborrheic dermatitis but are present in less than 5% of the cells in dandruff
-Seborrheic dermatitis is associated with inflammation
-Dandruff is not associated with inflammation
What are the differences used to diagnose seborrheic dermatitis versus psoriasis, impetigo, pityriasis versacolor, atopic dermatitis, and rosacea
-Psoriasis- No silvery scales
-Impetigo-No honey colored crusts and no bacteria present
-Pityriasis versicolor-No fungus present
-Atopic dermatitis-No allergic history and less itching. Difficult to differentiate
-Rosacea-No scalp and forehead involvement
What are the goals of treatment for seborrheic dermatitis?
-Reduce epidermal turnover rate
-Reduce or eliminate visible erythema
-Reduce inflammation
-Reduce pruritus
-Eliminate scaling
-This is a chronic disease that requires initial therapy followed by maintenance therapy
How does ketoconazole work to treat seborrheic dermatitis?
Helps reduce overgrowth of Pityrosporium ovale.
How is "cradle cap" treated?
-Gently massage baby oil into scalp
-Follow with a non-medicated shampoo to remove the loosened scales
-The condition usually clears spontaneously by 1 year of age
What is the disease process of pityriasis rosa?
-Within 1 week small, pale, erythematous, round to oval macular and papular lesions with fine scale appear on the trunk and extremities
-Usually no rash on face, hands and feet
-Lesions usually resolve in 7-14 days
What are the inflammatory lesions of acne?
Inflammatory lesions consist of papules, pustules, and cysts
What changes occur during puberty that lead to acne?
-Androgenic (testosterone) hormone production is increased
-Testosterone is taken up by the sebaceous gland and converted to dihydrotestosterone (DHT)
-DHT stimulates the secretion of sebum
-Sebum is thought to be the the main cause of acne
What is the first lesion that develops in acne?
Microcomedo.
What is the pathogenesis of inflammatory acne?
-Propionibacterium acnes (an anaerobic diptheroid) is a normal skin inhabitant
-P. acnes generates components that create inflammation
--Lipases
--Proteases
--Chemotaxic factors
-Lipases hydrolyze sebum to form free fatty acids
-Free fatty acids (FFA) are primary irritants
-It is though that FFA initiate inflammation
What is the role of chemotaxis factors in acne?
-They attract neutrophils to the follicular wall.
-Neutrophils release hydrolases which weaken the follicle wall
-The wall thins and eventually ruptures
-Primary inflammation develops with the disruption of the follicle wall
-Resulting lesion is an inflammatory papule
What is acne conglobata?
-Acne conglobata is a chronic highly inflammatory form of cystic acne
-Characterized by communicating blackheads and cysts
Where is neonatal acne located and what is its cause?
-Confined to nose and cheeks.
-Caused by maternal androgens that stimulate sebum secretion
-No treatment necessary
What kinds of lesions are associated with mild, non-inflammatory acne?
blackheads and whiteheads
What kinds of lesions are associated with mild inflammatory acne?
papules and pustules
What kinds of lesions are associated with moderate inflammatory acne?
papules, pustules, and some cysts
What kinds of lesions are associated with severe inflammatory acne?
many papules, pustules, and cysts
What kinds of lesions are associated with mild, non-inflammatory acne?
blackheads and whiteheads
What kinds of lesions are associated with mild inflammatory acne?
papules and pustules
What kinds of lesions are associated with moderate inflammatory acne?
papules, pustules, and some cysts
What kinds of lesions are associated with severe inflammatory acne?
many papules, pustules, and cysts
What are the goals of treatment of acne?
-Relieve social discomfort
-Remove excess sebum from skin
-Prevent closure of pilosebaceous orifice
-Unblock sebaceous ducts
-Reduce FFA formation
-Reduce conditions that cause acne such as the use of oil based cleansers and cosmetics
What is the course of treatment for non-inflammatory acne?
-Begin with tretinoin
-After patient adapts then add benzoyl peroxide or topical antibiotics
-Consider increase strength of tretinoin after 6 weeks of treatment
How does tretinoin work?
-Works by normalization of the follicular epithelium resulting in loosening of comedones
-Works on microcomedo causing expulsion of microplug
-Allows sebum to reach surface of skin preventing sebum buildup
-New comedo formation is prevented
-Converts closed comedo to open comedo
How does benzoyl peroxide work?
-Potent oxidizing effect results in antibacterial activity and suppress the population of P. acnes
-Causes irritation and desquamation that prevents closure of pilosebaceous orifice
-Promotes resolution of comedo by increasing epithelial turnover rate
-Is drying and reduces sebum on skin
What is the role of androgens in acne?
-Androgens increase sebum production
-Androgens promote hyperkeritinization and promote pilosebaceous plug
-Serum concentration of DHT is directly related to severity of acne
What are some oral contraceptives that have low androgenic activity?
-Desogen (desogestrel)
-Ortho-Cept (desogestrel)
-Ortho-Cyclen (norgestimate)
-Ortho Tri-Cyclen (norgestimate)
What are some oral contraceptives with high androgenic activity?
-Loestrin (norethindrone)
-Ovral (norgestrel)
-Lo/Ovral (norgestrel)
-Triphasil (levonorgestrel)
-Nordette (Levonorgestrel)
How does spironolactone work to treat acne?
-It is a potassium-sparing diuretic that has anti-androgenic activity
-Acts peripherally by blocking receptors for DHT in sebaceous glands
-Dose of 200mg/day suppresses sebum production by 75%
What are the actions of accutane?
-Reduction in sebaceous gland activity
-Reduces sebum secretion
Reduction in sebaceous gland size
-Reduces follicular keritinization
-Dissolves follicular plug
-Reduces P. acnes
What is the dosage of accutane?
-1mg/kg/day given for 4 months
-Cumulative dose may be more important than daily dose or duration of therapy
-Total dose of 120mg/kg is considered optimal
What are the lesions of rosacea?
-Begin as facial flushing over nose and cheeks
-Persistent erythema and telangiectasias
-Later development of inflammatory papules, pustules and perhaps even nodules
-No comedones
-Longstanding disease can result in rhinophyma
What are treatments of rosacea?
-OTC therapy does not work and may make the disease worse
-Oral antibiotics work reasonably well
-Tetracycline or erythromycin are treatments of choice
-1g/day is usual dose
-Medication is stopped when pustules have cleared
-Antibiotics will not help erythema to any great extent
Why is metronidazole used for treatment of rosacea?
-Does not work by killing P. acnes but by inhibiting oxidative tissue injury by neutrophils
-Takes 6-8 weeks to work and may be used in combination with oral antibiotics
What are the characteristics of dermatophytes?
-Superficial fungi live on the dead horny (keratin) layer of the skin and on the hair and nails
-Produce enzymes which digest keratin
-Results in epidermal scale, thickened crumbly nails, or hair loss
-Responsible for majority of skin, nail and hair fungal infections
-Cannot survive in mouth or vagina where keratin layer does not form
What are the 3 genre of dermatophytes?
-Trichophyton
-Epidermophyton
-Microsporium
What is the active border of a fungal infection?
-Highest concentration of infective organism is in border of rash
-Border is scaly, erythematous and slightly raised
-Central is lighter than border and may look “normal”
-Vesicles can occur in the border when inflammation is intense
-This pattern is present in all locations except on palms and soles of feet
What is vesicular tinea pedis?
-Highly inflammatory infection may originate from chronic interdigital infections
-Vesicles form on soles or on dorsum of feet
-Vesicles may enlarge to form bulla
-Secondary bacterial infections may occur
What drying agents can be used for tinea pedis?
Aluminum acetate soaks, talc, desenex af powder, zeasorb af powder
What some of the imidazole antifungal agents?
-Miconazole (Micatin-OTC)
-Clotrimazole (Lotrimin-OTC)
-Econazole (Spectazole-Rx)
-Oxiconazole (Oxistat-Rx)
-Sulconazole (Exelderm-Rx)
-Ketoconazole (Nizoral-Rx)
What are some of the characteristics of imidazole antifungal agents?
-These products not only kill dermatophyte fungus but yeast (candida) as well
-Take at least 4-6 weeks of treatment to cure infection
-Econazole is active against several bacterial species associated with severely macerated, interdigital interspaces
-All produce virtually no side effects
What are the Allylamine and Benzylamine Antifungal Agents?
-Allylamine Agents
--Terbinafine (Lamisil-OTC)
--Naftifine (Naftin-Rx)
-Benzylamine antifungal agents
--Butenafine (Mentax-Rx)
What are the characteristics of allyamine antifungal agents?
-These products not only kill dermatophyte fungus but yeast (candida) as well
-Allylamine type antifungal have proven to produce higher cure rates in the treatment of dermatophyte infections
-They produce more rapid response
-Have low relapse rates
-Usually require 2-4 weeks of treatment rather than 4-6 weeks of treatment
-All produce virtually no side effects
What kind of treatment is used for tinea barbae?
-Must use systemic therapy
-Sometimes infection is caused by fungus but becomes secondarily infected with bacteria
What are the systemic antifungal treatments?
-Terbinafine (Lamisil) 250mg/day for 2-4 weeks
-Itroconazole (Sporanox) 200mg/day for 2-4 weeks
-Fluconazole (Diflucan) 150mg/week for 3-4 weeks
What types of treatments are used for Tinea Cruris?
-The use of absorbent powders will help to control moisture and prevent infection
-They are applied until infection is gone and should then be used for a prolonged period of time to prevent reoccurrence
-Antifungal therapy should be with agents that have activity against candida
-Moist lesions can be treated with astringent soaks, powders, and topical antifungal therapy
What are the characteristics of tinea capitis?
-Most forms of tinea capitis begin with one or several round patches of scale or alopecia
-Black dot ringworm is caused by the fungus infecting and weakening the hair shaft which causes them to break off at the scalp surface.
-If the lesion becomes inflamed, it can resemble a large, wet, indurated, tumor-like mass
-This tumor-like mass is called a kerion
What are the characteristics of a candida infection?
-Rash in many cases is beefy red in color
-Pustules form but become macerated and develop into red papules with fringes of moist scaling at the border
-Intact pustules maybe found outside the opposing skin folds
-Tendency for painful fissure formation in the skin creases
What are the characteristics of tinea versicolor?
-A common infection caused by a type of yeast called Pityrosporum orbiculare
-May be contagious
-People with oily skin maybe more susceptible
-Excess heat and humidity may predispose a person for the development of the infection
-Multiple small, circular, white, macules found on the upper trunk
-Lesions are white on tanned skin and pink or brown on untanned skin
-Powdery scale is always found
What are some treatments for tinea versicolor?
-Selenium sulfide lotion 2.5% is applied and washed off in 10 minutes. Repeat daily for 7 days
-Treat the entire skin surface from the lower posterior scalp down to the thighs
-Ketoconazole shampoo is applied to dampened skin, lathered and left on for 5 minutes and then rinsed off. Repeat daily for 3 days.
-Response rate is about 70%
What type of bacterial skin disease can be treated topically?
Mild cases of impetigo, can be treated with Mupirocin (Bactroban).
Where do most piercing-related staph bacterial infections occur?
Most infections occur with piercing in the tongue, lips, and navels.
What are the types of secondary dermatological bacterial infections?
-Infected ulcers
-Infected atopic dermatitis
-Infected fungal infections
-Bacterial intertrigo
What are some of the types of systemic bacterial infections that present on the skin?
-Scarlet fever
-Leprosy
-Meningococcal meningitis
-Lyme Disease
What are the types of primary dermatological bacterial infections?
-Known as pyodermas
-Impetigo
-Cellulitis
-Folliculitis
-Furuncle
-Carbuncle
-Erysipelas
What types of bacteria cause skin infections?
-Staphylococcus aureus
-Group A beta-hemolytic streptococci
What types of infections does staphylococcus aureus cause?
-Impetigo
-Folliculitis
-Furuncles
-Carbuncles
What are the characteristics of the lesions of bullous impetigo?
-Lesions begin as vesicles
-Enlarge to form bulla
-Bulla form with very thin, fragile roofs
-These bulla collapse leading to an inner-tube-shaped rim with a thin, flat, center that is often associated with honey colored crusts
-Lesions enlarge and often coalesce.
-Minimal surrounding erythema and no pain
-Toxins produced by S. aureus are responsible for the lesions of bullous impetigo and staphylococcal scalded skin syndrome
What are the characteristics of non-bullous impetigo?
-Also known as crusted impetigo
-Originate as small vesicle or pustule that ruptures to expose a red, moist base
-Firmly adherent crust accumulate
-Crusts in many cases are honey-colored
-Little surrounding erythema
-Skin around nose, and mouth are most commonly affected
If impetigo remains untreated, what serious disease can it lead to?
post-streptococcal glomerulonephritis
What is used for the systemic treatment of impetigo?
-A 10 day course of antibiotics that will kill both staph and strep is effective
-Penicillin is not a good choice because most strains of S. aureus are resistant
-Erythromycin is a good choice except in those communities where resistant strep have been isolated
-Cloxacillin and dicloxacillin are active against staph but not nearly as active against strep
-Cephalexin is active against strep and staph and significant resistance has yet to develop at least as it applies to the treatment of impetigo
What is cellulitis?
-characterized by erythema, edema and pain
-an infection of the dermis and subcutaneous tissue
-Infection of the dermis and subcutaneous tissue caused by group A beta-hemolytic streptococci and S. aureus
-Occurs near surgical wounds and other trauma sites such as insect bites, abrasions, and ulcers
What is erysipelas?
-Erysipelas is similar to cellulitis except that it involves the lymphatics and “streaking” is common
-Erysipelias is also more clearly demarcated than cellulitis
-Infection of the dermis and subcutaneous tissue caused by group A beta-hemolytic streptococci and S. aureus
-Occurs near surgical wounds and other trauma sites such as insect bites, abrasions, and ulcers
What are the characteristics of lesions associated with folliculitis?
-Dome-shaped pustules with small erythematous halos
-Inflammation may be intense and painful
-Lesions are in a follicular arrangement
-Most common bacteria associated with folliculitis is S. aureus
What is the treatment for severe folliculitis?
-Claxacillin
-Dicloxacillin
-Cephalexin
-Cefuroxime
What are the characteristics of a furnucle?
-Also called an abscess or a boil
-Walled-off collection of pus
-Any hair bearing site can be affected
Painful, and usually firm
-The deep, painful, firm subcutaneous mass points and drains through multiple openings
-Cellulitis may precede or occur in conjunction with it
-S. aureus is most common pathogen
-Patient remains afebrile
-Many furuncles are self-limiting and respond well to a minimum of treatment
What is the course of treatment for furuncles?
-Warm, moist compresses are applied 15-30 minutes 2-4 times/day if lesion is deep seated
-Drainage (I&D) is the primary management for pointing, fluctuant lesions
-Antibiotic therapy can be used for recurrent furuncles
-Anti-staphylococcal antibioitcs are taken at the very first sign of localized swelling and erythema
-Continue for 5-10 days
What is the cause of pseudofolliculitis barbae?
-Foreign-body reaction
-Hair follicles orient at a oblique angle to the skin surface
-A sharp, shaved, tapered hair reenters the skin as it grows from below the skin surface and causes an inflammatory reaction that results in microabcess formation
What is the cause of warts?
-Caused by human papilloma virus (HPV)
-Virus infects keratinocytes resulting in epidermal proliferation
-Papules, corrugated, hyperkeratotic growths confined to the epidermis
How is HSV transmitted?
-Skin to skin
-Skin to mucosa
-Mucosa to skin
What are the symptoms of a primary HSV infection?
-Symptoms begin 3-12 days after contact
-Tenderness, pain, and mild paresthesia precede the onset of lesions in most cases
-Gingivostomatitis and pharyngitis are most frequent manifestations of first episode
-Localized pain, tender lymphadenopathy, generalized aching, and fever are characteristic symptoms associated with the primary infection
How long does it take for HSV-1 lesions to heal?
-2 to 6 weeks without scarring.
What are some topical non-antiviral treatments for HSV-1
-Cool compresses decrease erythema and debrides crusts to promote healing
-Tetracaine cream (Viractin) which is OTC helps with pain and may help enhance healing
What are the topical antiviral treatments for HSV-1
-Penciclovir (Denovir) when applied Q2H reduces the duration of disease 1-3 days
-Topical acyclovir (Zovirax) is not effective for the treatment of HSV-1 infections
What systemic treatment is used for severe primary HSV-1?
-Valacyclovoir (Valtrex) 1gm po BID for 10 days
-Acyclovir (Zovirax) 200mg 5 times/day for 10 days
-Most effective when given within 48 hours of first sign of infection
What systemic treatment is used for severe recurrent HSV-1?
-Valacyclovoir (Valtrex) 500mg po BID for 5 days
-Famciclovir (Famvir) 125mg BID for 10 days
-Acyclovir 400mg TID for 5 days
What chronic suppressive therapy is used for HSV-1?
-Used when there are more than 6 recurrences/year
-Valacyclovoir (Valtrex) 500mg po QD for 6-12 months
-Famciclovir (Famvir) 250mg BID for 6-12 months
-Acyclovir 400mg BID for 6-12 months
What is the cause of shingles?
-Disease results from re-activation of varicella virus that entered the cutaneous nerves during an earlier episode of chicken pox
What are the characteristics of the lesions of herpes zoster?
-Usually limited to the skin of a single dermatome
-Eruption begins with red, swollen papules and spread to involve all or part of the dermatome
-Vesicles arise in clusters in the 3rd or 4th day along the dermatome and become cloudy with purulent fluid
-Vesicles vary in size in contrast to the relatively uniform size in HSV
-Vesicles rupture and form crusts which fall off in 2-3 weeks
Herpes zoster can have the involvement of which cranial nerve?
CN V, opthalmic branch
What are some of the general therapies for herpes zoster infections?
-Wet compresses with tap water or Burrow's solution
-Apply for 20 minutes 3 times daily
-Macerate vesicles, removes serum and crusts, suppresses bacterial growth
-Calamine Lotion
-Covering the lesion with an occlusive dressing (cotton & elastic bandage)
-Oral Analgesics
How are oral corticosteriods used to treat patients with herpes zoster infections?
-Will reduce the severity of pain and edema and is very useful in patients with ocular zoster
-Must be started within 5 days of eruption
-Dose is 40-60mg/day and then tapered over a 3-4 week period
-Does not seem to reduce time to healing or cause dissemination of the disease
-Decrease incidence of post-herpetic neuralgia
What is post-herpetic neuralgia?
-Pain can persist in a dermatome for months or years after lesions have disappeared
-Occurs in 10-15% of patients
-Pain can be severe and debilitating
-Mechanism of pain has not been established
-No really good treatment
What are some treatments for post-herpetic neuralgia?
-Capsaicin (Zostrix and Zostrix-HP cream)
--Depletes pain impulse transmitter substance P and prevents re-synthesis
--Applied 3-5 times/day
-Studies have shown that Amitriptyline 75-100mg/day in combination with thioridazine 25mg qid provided good to excellent pain relief in patients with PHN
-Early treatment is essential
What is the incubation period of varicella?
14-21 days
For what period of time is a person with varicella contagious?
Patients are contagious from 2 days before onset of rash until all lesions have crusted over
What are the treatments for varicella?
-For healthy children treatment is symptomatic
-Calamine lotion
-Oral antihistamines (Diphenhydramine)
-Mild antipruritic lotions such as Sarna
-For adolescents and adults give early therapy with acyclovir
Acyclovir 800mg 5X/day for 5 days
-Beginning therapy after first day of illness is of no value in uncomplicated cases
What is used to prevent insect bites/stings?
-Insect repellents
-Useful for repelling biting insects such as mosquitoes, fleas, ticks, and chiggers but not spiders
-Not use for repelling stinging insects
-Most products contain DEET
-Tends to make you unappealing to the insect
What are some local anesthetics used to treat insect bites/stings, and what are their side effects?
-Benzocaine and lidocaine may cause allergic contact dermatitis
-Pramoxine produces virtually no side effects and does not exhibit cross sensitivity with other anesthetics
-Dibucaine is a common allergen and may cause systemic toxicity such as convulsions and myocardial depression if used on large areas where skin is not intact
What are some characteristics of spiders and their bites?
-All spiders are carnivorous and poisonous
-Most spiders are small and have fangs that cannot penetrate human skin
-Most spider bites cannot be felt when the occur but within a few minutes a painful, hive-like swelling develops
-Most spider bites cause pain, swelling and inflammation
-Area becomes warm and erythematous
-Sometimes two fang marks can be observed in the skin
What are the characteristics of a black widow spider bite?
-Bite may produce sharp pain or may be painless
-Venom is a neurotoxin that is absorbed by the lymph system and distributed by the blood vessels
-15 minutes to 2 hours after bite muscle cramping or spasms and pain develop which spreads from the bite site to the entire torso.
-Spasms most severe in abdomen and legs
What is used to treat pain and severe muscle spasms associated with black widow spider bites?
-Combination of IV morphine and diazepam (Valium)
-After 1-2 hours the dose can be repeated if necessary
-If more therapy is needed, oral rather than IV doses are given
-Calcium gluconate may also be used to relax muscles and help relieve pain
What is used to treat brown recluse spider bites?
-Ice and elevation
-Exercise is avoided
-Antibiotics and NSAIDs are usually given
-No antivenin is currently available
-Dapsone at a dose of 50 to 100mg/day has been found to be useful in controlling severe symptoms
--Helps to prevent venom induce perivasculitis
What are the standards of triage for insect/spider stings/bites?
-Refer all tick bites
-Refer all spider bites
-Refer if reaction is not confined to site of bite
-Refer if signs of systemic allergic reaction
-Refer if symptoms do not respond within 7 days
What are the 3 species of lice that affect humans?
-Infestation by Pediculus humanus capitis causes head lice
-Infestation by Phthirus pubis causes pubic lice
-Infestation by Pediculus humanus corporis causes body lice
What are the characteristics of lice?
-Lice feed about 5 times/day
-Claws pierce skin, inject irritating saliva, and suck blood
-Lice feces can be seen on the skin as small rust-colored flecks
-Feces and saliva are responsible for inflammatory reaction and itching associated with infestation
-Live about one month
-Female lays about 6 eggs or nits/day
How long does it take for lice eggs (nits) to hatch?
7-10 days
How do Pyrethrins work?
-Come from chrysanthemums
-Interfere with neural transmission which leads to paralysis and death
-PBO potentates pyrethrins by inhibiting arthropod enzymes responsible for hydrolyzing pyrethrins
-May be used on infants, young children, and pregnant or lactating women
What can be used to break the chitin bond that binds nits to hair?
-Vinegar (acetic acid)
-Step 2 (formic acid)
-Apply these products on hair after shampooing. Apply chitin-breaking soaks for 10-15 minutes before combing out nits
What other topical therapy is used in resistant cases of lice?
-Malathion 0.5% Lotion (Ovide)
-Malathion is pediculicidal and ovidicidal
What oral therapy is used in severe infestations of lice?
-Rare patients with severe hair matting and dense infestation may not respond to topical therapy
-Several small studies showed taking trimethoprin-sulfa bid for 3 days resulted in a cure
-Within 24-48 hours after completing treatment, dead lice were found on all patients bed sheets
What is the organism that causes scabies?
Caused by the mite Sarcoptes scabiei hominis.
What are the typical areas that scabies are found?
wrists, finger webs, feet, and genital area
What are the secondary lesions of scabies?
They have an eczematous reaction pattern associated with many excoriations.
What can be used for inflammation and itching associated with scabies?
-Group V topical corticosteriods.
-Nighttime itching can be treated with diphenhydramine.
What are risk factors for developing skin cancer?
-long-term unprotected exposure to sun
-many severe sunburns
-blonde or red hair
-a history of freckling
-a tendency to burn rather than tan
What are the 3 major bands of UV radiation?
-UVA Radiation 320-400nm (Long-Wave Radiation)
-UVB Radiation 290-320nm (Sunburn Radiation)
-UV-C Radiation 200-290nm (Germicidal Radiation)
What are the characteristics of UVA radiation?
-Not associated with production of erythema but of a slowly developing tan
-Penetrates deeper into skin than UVB radiation
-Used in tanning beds
What are the characteristics of UVB radiation?
-Major cause of true sunburn
-Chronic to exposure to UVB radiation is the major cause of photo-aging and skin cancer
-Carcinogenic effect is augmented by UVA
-Implicated in the development of cataracts
What are the effects of photo-aging?
-Mild damage results in dry, rough skin, appearance of age spots, fine lines and wrinkles
-Fat and collagen in dermis declines
-Capillaries become dilated producing visible telangiectases
-Skin thins, sags and becomes susceptible to bruising
-Development of solar lentigos
What are actinic (solar) keratoses?
-Clumps of abnormal keratinocytes
-Rough, dry, scaly lesions found on the hands, face, arms and other regions of high sun exposure
-Slow growing and do not flake off when touched
-Considered “pre-malignant” and should be removed
-Associated with development of squamous cell carcinoma
What is the therapy for solar keratoses?
-Cryotherapy is the treatment of choice for isolated superficial lesions
-5-FU (fluorouracil) solution or cream is treatment of choice for more extensive disease
What are the phases of treatment of solar keratoses?
-Early inflammation phase
-Severe inflammation phase
-Lesion disintegration phase
--Erosion, ulceration, intense inflammation, discomfort , pain, crusting, and escar formation
-5-FU application is stopped when patient enters lesion disintegration phase
What are the characteristics of basal cell carcinomas?
-White, or colored, pearly and translucent with a rolled edge
-Arises from the basal cell layer
-Occurs most frequently in people exposed to sun
-Can cause massive tissue destruction but do not metastasize
-Are curable
What are the characteristics of squamous cell carcinomas?
-Most arise on sun damaged skin and from skin lesions diagnosed as actinic keratosis
-Painless, scaly, and crusted.
-Usually red in color
What are the ABCs of melanoma?
-Asymmetry
-Border
-Color variegation
-Diameter greater than 1/4” (6 mm)
What are the characteristics of a photo-allergy?
-True allergic reaction
-Lesions are hives rather than a sunburn
-May spread to parts of the skin not exposed to sunlight
-Each subsequent exposure will give a more intense reaction
-Develops in a very small percentage of patients
What are the characteristics of photo-toxicity?
-Appears more like a sunburn than allergic reaction
-Not immune related and can occur after single exposure to drug and sunlight
-Occurs only in those areas exposed to UV radiation
What is MED?
-minimal erythemal dose
-Smallest amount of sun exposure necessary to produce redness
-Measured in millijoules/square centimeter (MJ/cm2)
-1 MED produces slight redness
-2 MEDs produces bright redness
-8 MEDs produces severe burn with blistering
How does MED relate to skin type?
-Type II skin requires about 25 MJ/cm2 to produce 1 MED
-Type VI skin requires about 200 MJ/cm2 to produce 1 MED
-A person with type II skin will receive 1 MED after about 15 minutes of sun exposure
How is SPF calculated?
-Divide: MED of skin protected by sunscreens/MED of unprotected skin
SPF 10 = 250 MJ/cm2 ÷ 25 MJ/cm2
What are some of the chemical sunscreens?
-PABA derivatives
-Anthranilates
-Benzophenones
-Cinnamates
-Dibenzoylmethane derivatives
-Salicylates
-Methylanthranilate
What is Stevens-Johnson syndrome?
Stevens-Johnson Syndrome is a rare disorder characterized by inflammation of the mucous membranes of the mouth, throat, anogenital region, intestinal tract and membrane lining the eyelids (conjunctiva). Affected individuals may have abnormalities (lesions) of the skin and mucous membranes that are purplish or red in color. The abnormalities may be flat (macules) or small and raised (papules). In some cases, the lesions may develop raised fluid-filled centers (bullae or blisters). Affected individuals may also have blisters and/or bleeding in the mucous membranes of the lips, eyes, mouth, nasal passage, and genitals.
What is Toxic Epidermal Necrolysis?
It is characterized by blisters that meld into one another to cover a substantial portion of the body (30% and more), and extensive peeling or sloughing off of skin (exfoliation and denudation). The exposed under layer of skin (dermis) is red and suggests severe scalding. Often, the mucous membranes become involved, especially around the eyes (conjunctivitis), but also the mouth, throat, and bronchial tree.
What is Erythema Multiforme?
Erythema Multiforme is an inflammatory skin disorder characterized by symmetric red and blistery (bullous) lesions of the skin or mucous membranes of the hands, feet and eyelids.