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55 Cards in this Set
- Front
- Back
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Name the four layers of the epidermis (deep to superficial).
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Basal, spinous, granular, cornified.
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What helps keratinocytes in the spinous layer adhere to each other?
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Desmosomes.
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What kind of granules are in the granular cell layer keratinocytes?
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Keratohyaline.
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What is a melanosome and what is its function?
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A melanin pigment-containing organelle produced by the melanocyte. It absorbs UV radiation.
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What is the Langerhans cell's function and what kind of granules does it have?
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It's an APC that has Birbeck granules.
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What is the function of a Merkel cell and where in the epidermis can you find it?
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The Merkel cell senses touch and is found in the basal layer of the epidermis adjacent to nerve fibers.
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Name the three sections of the hair follicle.
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Infundibulum (surface to sebaceous gland), isthmus (sebaceous gland to arrector pili insertion), lower part.
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How can you tell the apocrine glands from the eccrine glands?
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Apocrine glands have a much bigger diameter and are only found in the axilla, groin, and areola.
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What are the two most common lesions associated with pilosebaceous units?
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epidermal inclusion cysts (infundibulum of follicle) and leiomyoma (associated w/ arrector pili muscle)
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Which of the following is a secondary lesion:
a. plaque b. nodule c. erosion d. bulla |
c. erosion
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What are the steps in a KOH prep and what does it test for?
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Put scrapings from a lesion on a slide. Add KOH, heat the slide gently, and drain the excess KOH. Look for hyphae.
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What are the steps in a Tzanck smear and what does it test for?
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Unroof a blister, scrape the base, and smear it on a slide. Wright or Giemsa stain for 5-10 min, then rinse with tap water. Look for multinucleated giant cells to confirm the presence of a herpes virus.
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What is mutated in Epidermolysis bullosa simplex?
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keratin 5 or 14 in desmosomes.
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Name two diseases that cause mutations in or antibodies to hemidesmosome proteins.
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Junctional EB (collagen 17, integrins, laminins) and pemphigoid (collagen 17, plakins).
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What two diseases have a mutation in collagen 7 that leads to scarring?
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dystrophic EB and EB acquisita.
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What are the immunofluorescence patterns for
a) pemphigus b) pemphigoid |
a) net-like
b) linear |
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What causes impetigo? If the causative agent makes exfoliative toxins, what desmosomal antigen is affected?
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Staph aureus- it can affect desmoglein 1 and lead to SSSS.
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What type of Ig is involved in type I hypersensitivity and what are the skin manifestations of type I HS?
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IgE; urticaria and/or angioedema.
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What type of hypersensitivity is pemphigus? What kinds of Ig are involved?
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type II- cytotoxic. IgM and IgG are involved.
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Describe the pathophysiology of type III hypersensitivity. What clinical manifestations does it cause?
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Antigen-antibody complexes get trapped below vascular endothelium leading to vasculitis.
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What is the pathophysiology of type IV hypersensitivity and what is its clinical manifestation?
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Activated T lymphocytes lead to pruritic areas of erythema, edema, and vesiculation. (allergic contact dermatitis)
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What type of hypersensitivity doesn't involve Ig, antibodies, or T lymphocytes?
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type V- irritant contact dermatitis. Often occupational.
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What are diagnostic criteria for atopic dermatitis?
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Pruritus plus at least three of the following: Hx of flexural eczema, Hx of asthma or arthritis, dry skin in last yr, onset before 12 y.o., flexural dermatitis.
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What are the etiology and pathogenesis of atopic dermatitis?
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Unknown etiology, but perhaps increased IgE due to skin staph, defective CMI, inflammatory mediators, family history of atopy.
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How old are most patient when they first get atopic dermatitis and how do you treat it?
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60% of pts get AD at < 1 year of age; 90% of pts with AD have it by 5 y.o. Treat with moisturizers, avoidance of aggravating factors. No cure.
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What are the skin changes seen in SLE?
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photosensitivity, painless oral ulcers, malar eruption, erythema (sparing DIP and PIP) on hands
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What are the skin changes seen in dermatomyositis?
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photosensitivity, heliotrope eruption, Gottron's papules. (look for purple on upper eyelids w/ periorbital edema)
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Where on the body would you see Gottron's papules and what disease are they associated with?
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Knuckles, elbows, knees- associated w/ dermatomyositis.
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What skin lesions would you see in a patient with vasculitis?
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Palpable purpura (raised, non-blanching erythema). Lesions are often symmetric and are found on the legs.
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What are the cutaneous manifestations of neurofibromatosis type I?
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ptic gliomas, at least 6 cafe-au-lait macules (at least 1.5 cm across), sphenoid dysplasia, Lisch nodules (iris hamartomas), axillary freckling (Crow's sign)
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What is the hyponychium?
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the area under the free edge of the nail plate.
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What is the visible part of the nail matrix called?
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lunula
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What are the clinical nail-related findings in psoriasis?
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nail plate pitting, onycholysis, subungual hyperkeratosis, "oil spots" or discoloration due to glycoprotein deposits under the nail.
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What phase of hair growth determines hair length?
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anagen.
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What would a hair removed from the scalp during anagen look like? in telogen?
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Anagen: ragged end with parts of the surrounding sheath. Telogen: club-like, rounded terminal end with no sheath.
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What causes androgenetic alopecia (hmm...) and what treatments are available?
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Inherited sensitivity to circulating androgens; treatable with minoxidil or finasteride.
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What are some causes of telogen effluvium?
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childbirth, emotional stress, meds.
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What is the clinical manifestation of alopecia areata and what is the type of hair associated with its lesions?
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discrete bald patches with exclamation point hairs at the patch periphery.
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What are causes of anagen effluvium?
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Chemo, poisoning, nutritional deficiency- it's pretty rare.
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Would a red, scaly lesion be due to lymphocytic or neutrophilic scarring hair loss?
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Lymphocytic. Neutrophilic presents w pustules, crusting.
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What's the clinical presentation of body lice?
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Excoriations, erythematous papules, eczematous changes, urticaria on the back, waist.
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How long after infection with lice does a patient begin to show symptoms?
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One week for initial infestation; within 24 hours for subsequent infestations.
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How should you treat a lice infestation?
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Pyrethrin cream applied for 10 minutes, then rinsed; repeat after 7-10 days. Alternatively, permethrin shampoo- don't use in kids, nursing moms.
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Which of the following causes hyperpigmentation due to an increased number of melanocytes?
a. UV radiation b. hyperthyroidism c. minocycline d. cafe au lait macules |
a. UV radiation
d. cafe au lait macules |
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What causes the change in pigmentation seen in minocycline-induced pigmentation- both focal and diffuse?
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focal: accumulation of macrophages w/ inclusions that stain for hemosiderin.
diffuse: increased basal melanization, minocycline complex in dermal macrophages. |
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What are the gross and microscopic findings in amiodarone-induced hyperpigmentation?
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micro: yellow-brown granules in dermal macrophages.
gross:slate gray color to exposed areas, blue/red on hands and feet. |
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What conditions/drugs are associated with melasma?
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Pregnancy, OCP use.
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What causes hyperpigmentation in UV exposure?
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Increased synthesis and transfer of melanosomes to keratinocytes.
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Name 3 systemic diseases that can cause hyperpigmentation.
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Addison's, neurofibromatosis, scleroderma.
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Which of the following conditions causes destruction of melanocytes?
a. albinism b. tinea versicolor c. piebaldism d. vitiligo |
c. piebaldism (in some cases; in other, there are just fewer melanocytes)
d. vitiligo |
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Name 3 conditions that may be associated with vitiligo.
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hyperthyroidism, pernicious anemia, psoriasis, adrenocortical insufficiency, alopecia areata.
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How can you treat vitiligo?
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steroids, photochemotherapy, depigmentation, surgery, skin grafts, tattooing
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How is piebaldism inherited and how does it affect melanocytes?
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Autosomal dominant.
It causes a lack of melanocytes or, rarely, destruction of melanocytes. |
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How do the number of melanocytes compare in a patient with albinism and a normal patient?
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Same.
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Describe the hypopigmentation pattern of idiopathic guttate hypomelanosis- grossly and microscopic features.
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Discrete hypopigmented macules 2-5 mm across.
Decreased density of melanocytes, less melanin. |
