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137 Cards in this Set
- Front
- Back
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How often does skin slough off? |
Every 25-45 days |
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What is the criteria of normal flora? |
1. resistance to drying 2. resistance to salt 3. grow in clumps |
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Normal Flora species |
Staphylococcus epidermidis Corynebacterium diptheriae Candida sp Staph aureus Bacteroides Hemophilus |
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Macule |
Flat, lesion with color change |
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Papule |
small elevated solid bump
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vesicle |
Elevated lesion filled with clear fluid |
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Bulla |
Large vesicle
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Pustule |
Small elevated lesion filled with pus |
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Petichiae |
Small purpura (reddish purplish discoloration due to blood in small areas of tissue) |
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Abcess |
Deeper dissue, decreased blood flow and therefore antibiotics don't penetrate well |
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Staphylococcus Aureus |
Gram + cocci in cluster |
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Staph Aureus infection |
Folliculitis (hair follicle infection) Sty (eyelash infection) Cellulitis and boils |
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Boils |
Must lance to drain boil and culture |
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Staph Aureus Impetigo (bullous) |
on surface of skin impetigo |
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Impetigo |
vesicle around mouth |
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Carrier state of Staph Aureus |
Nose (20-40%) Skin (25%) |
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Transmission of S. aureus |
Fomites |
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What is the major cause of skin disease in the US? |
community acquired MRSA |
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What are the virulence factors of S. Aureus |
Adhesins, antibiotic resistance, cytotoxic factors peptidoglycan, clumping factor, Protein A (binds to Fc to IgG and no signaling of immune cells) Coagulase (causes clotting, hide inside and not be recognized), siderophobes, breaks hyaluronidase which holds skin together, collagen binding proteins |
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Where can S. Aureus cause infection in the body? |
Surface (impetigo) Enteritis (diarrhea) Toxic Shock Everywhere in body Pneumonia Food Poisoning |
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2 Types of MRSA |
Community acquired Hospital Acquired |
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Which RMRSA contains the PVL gene? |
Community acquired
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Which MRSA is resistant to all antibiotics except Vancomycin? |
Hospital acquired |
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Treatment of S. Aureus |
Methicillin, penicillin, vancomyocin |
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Prevention of S. Aureus |
Cleanliness Maintain innate immunity New vaccine for compromised dialysis patients |
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What is S. aureus Toxemia |
The toxin is responsible for symptoms No bacteria at site of skin manifestation |
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What are the s. aureus toxicemias? |
Toxic Shock syndrome Scalded skin syndrome |
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Scalded Skin Syndrome |
Toxemia of s. aureus Bacteria colonize in the intestine of newborn and children less than 2 Toxin enters the bloodstream and affects the epidermis |
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Virulence factors of Scalded Skin syndrome |
Exfoliative toxin a and B -destruction of intracellular connective tissue -skin peels off in sheets
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Toxic Shock Syndrome
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Colonization elsewhere, toxin enters bloodstream
Effects: fever, vomiting, sunburn-like rash, leads to peeling skin |
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When does Toxic Shock Syndrom occur?
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TSST-1,
-menstrual TSS occurs in association with tampons, incidence rises w/ increases in absorbency, tampons too long -nasal surgeries |
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Virulence factors of Toxic Shock Syndrome
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TSST-1:superantigen,
(ability to stimulate t cells and induce TNF and IL-2 |
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Diagnosis of Toxic Shock
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Culture on blood agar
Verify TSST-1 toxin with 1) RIA 2) ELISA 3) PCR |
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Gram stain of Streptococcus Pyogenes
(Group A Strep |
Gram positive cocci in chains
(greater invasiveness than staph) |
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Skin infections cause by group a strep
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1) impetigo
Vesicular 2) Erysipelas-infection of dermal layer, tissue destruction, can lead to sepsis 3)late sequelae -acute glomerulonephritis -rheumatic fever (less common) |
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How do you get GAS? (Epidemiology)
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Direct contact with lesion (highly infectious)
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Virulence Factors for GAS
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-Hyaluronic acid capsule
-M protein (outside cell wall fuzzy fibril layer that inhibits phagocytosis) |
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LTA
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Lta is anchored to proteins on bacterial surface, including m protein, mediate bacterial adherence to host epithelial cells
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Exotoxins
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Streptokinase, hyaluronidase
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Diagnosis of GAS
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-Gram + cocci in chains
-Culture Beta hemolytic -Catalase - -Group A carbohydrate teichoic acids |
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Treatment of GAS infection
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Antibiotics
Must prevent late sequaelae -acute glomerulonephritis -follows infections with skin M types of S. progenies -Immune complex disease type III -No live bacteria (has cleared and gone) |
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Prevention of GAS skin infections
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No vaccine
Treat rapidly so you don't build antibodies |
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Toxemia of staph
Necrotizing fasciitis |
Flesh eating strep
Rapid disease course, destroys tissue as quickly as removed |
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Epidemiology of Necrotizing fasciitis
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can cause death and loss of limbs
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Virulence Factors of necrotizing fasciitis
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-Pyrogenic exotin A (SPE A) -superantigen: bypasses regular immune system and your own response kills you, overrides regulatory system inflammation (fever causing)
-Streptolysin O (SLO) lyses cells, assist spread through tissues and exaggerated immune response |
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Diagnosis of necrotizing fasciitis
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culture on blood agar
Beta hemolytic Group A Immunological Assays for toxin |
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Treatment for Necrotizing Fasciitis
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-antibiotics (penicillin)
-wound debridement almost always necessary |
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Strep Toxic Shock Syndrome
(Toxemia) |
similar to staph toxic shock
less frequent rash and more frequent bacteremia, shock and organ damage Toxin TSS-1 |
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Propionibacterium acne
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opportunistic pathogen, normal flora grows out of control
Acne: inflammatory, whitehead (closed comedo), Blackhead (open comedo) |
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Treatment of acne
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-benzoyl peroxide
-rein A -blue light |
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Pseudomonas Aeruginosa
Gram stain and where is it found? |
Aerobic gram - rod
Naturally found in soil and water Strict aerobe Very common |
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Pseudomonas dermatitis
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Disease of Pseudomonas aeurginosa
-rash from swimming in pool/hot tubs |
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Ottis externa
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Disease of Pseudomonas aeruginosa
ear infection of external canal -outer ear canal -swimmer's ear |
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Epidemiology of Pseudomonas Aeurginosa
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opportunistic pathogen ,lives in the dirt , comes across frequently
-nosocomial infections (resides in sink drains) -Very naturally antibiotic resistant, few antibiotics effective -HARD TO TREAT |
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Virulence Factors of pseudomonas aeruginosa
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produces exotoxin A
dense biofilm in cystic fibrosis patients lungs |
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Diagnosis of Pseudomonas Aeruginosa
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culture on routine media
-non-lactose fermentor mac agar -oxidase + - Grape-like odor -green, green-blue pigment |
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3 ways pathogens attack
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1) breach of intact skin
2) skin manifestation of a systemic infection (infection is all over but can only see it on skin) 3) Toxin-mediated skin damage |
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Measles
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rubeola virus
rash -macular red flat rash, face, starts at trunk -KOPLICK'S SPOTS: tiny red patches, white center, enough to diagnose |
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Epidemiology of measles
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can be highly virulent (w/in 7 ft of infected patient, 90% change of getting it)
-humans only reservoir (human to human spread) -mortality in very young and old -spread by respiratory droplets (7ft) -rare serious sequelae occur |
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Subacute Schlerosing Panencephalitis (SSPE)
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Rare event 1/million male children and young adults infected
1-10 years after measles infection brain issues, disorientation, can't walk always fatal Worst Case scenario |
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Diagnosis of Measles
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look for signs and symptoms
-rash and koplick's spots |
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Treatment for measles
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None
Quarantine not real effective spread before you had symptoms |
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Prevention of measles
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Vaccine MMR
-live attenuated strain of virus (pass it until not an infection but still giving measles-1 cell memory and b cell memory, downside is can't get disease |
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MMR
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Measles, mumps, rubella vaccine
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German Measles (Rubella)
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Low-grade fever and rash
encephalitis rare (brain issues) Real problem is congenital rubella syndrome (spread through respiratory route to pregnant woman |
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Epidemiology of Rubella
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-spread by respiratory route
-severe birth defects when mom infected during 1st trimester and ability to stop mitosis, baby usually not even born (-used to do a blood test for rubella before marriage) |
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Prevention of Rubella
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Vaccine MMR, live attenuate strain of virus
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Fifth Disease (parvovirus B19-distemper)
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fifth eyrthema infectiosum
5th of list of skin rashes Butterfly rash of face for kids Spike a fever and then it goes away |
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Epidemiology of fifth disease
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-Mild flu-like symptoms
-Slapped cheek butterfly rash -Self-limiting so no treatment |
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Roseola
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-Human herpesvirus 6 (HHV6)
-very common rash -High fever few days, rash lasts day or 2 longer |
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Five Exanthems
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1. varicella
2. measles-rubeola 3. rubella 4. roseola 5. fifth disease |
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Chickenpox
-name -symptoms |
Varicella-zoster(reactivation)
-herpesvirus 1 varicella is chicken pox fever, vesicles, scabs, lasts 10 day Latent infections in nerve cells-dorsal root ganglion of spine |
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Zoster
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Shingles, relapse of chicken pox
sits in spine until reactivation very painful most cases in adults over 50 increasing in younger adults |
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Epidemiology of Chicken pox
-spread? -complications? |
spread by respiratory secretions
most people get vaccine or have had chicken pox mostly get it in childhood, secondary is cellulitis when scratching (treat with antibiotics) complications are encephalitis pneumonia and is more dangerous in adults |
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Reye's Syndrome
-cause? -symptoms? |
in children
caused by taking aspirin for fever vomiting and brain disfunction should take tylenol or motrin |
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Treatment for Varicella-Zoster
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Chicken pox: tylenol, motrin for fever and anti-itch treatment
Shingles: treat only severe cases-antiviral drugs |
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prevention of varicella-zoster
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Vaccine
-live attenuated vaccine which causes latent infection -attenuated vaccine virus can reactivate and cause herpes zoster -children vaccinated appear to have a lower risk of zoster than people who were infected with wild type |
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Smallpox
-name |
Variola major (20% mortality rate)
Viriola minor (<10% mortality rate) |
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Epidemiology of smallpox
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successfully eradicated
epidemics with mortality biological warfare (us and Russia) respiratory route (human to human only) |
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Prevention of smallpox
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Vaccination COW POX
-successful elimination from earth? -waning immunity in population Monkey pox? -conco-jumped from monkey to human (was an outbreak in 2003) |
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Herpes Simplex Virus
-Types, symptoms |
HSV-1 and HSV-2
-cold sore, genital herpes, skin herpes (herpes gladitorum, wrestlers) -whitlow (inoculation herpes)- dentists spread to hands from cold sores |
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Herpes encephalitis
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Rase spread to brain
Latent infections in nerve ganglion relapse (reactivation-stress, sun, UV) |
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Epidemiology of Herpes
HSV1,2 |
-90% of population infected
HSV1 is oral previously HSV2 genital previously currently mixed |
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Treatment of Herpes
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Acyclovir ACA Zovirax
Treatment must be early to prevent sores |
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Prevention of herpes
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Prevent direct contact with lesions
Virus killed by soap |
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WArts
-How many types? -Incubation period? |
Papillomavirus
-more than 80 types -incubation period is weeks -infection lasts for years -hyperplasia of sin cells |
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How are warts spread
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spread from hand to hand
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Treatment of warts
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Cryosurgery:cold liquid nitrogen
laser Acid (over the counter) |
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Prevention of warts
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None, not cancer association
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Mooluscum Contagiosum
-name? symptoms? |
Poxvirus
wart-like in children Direct contact, autoinoculation |
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Dermatophytes
What kind of infection? Where does it grow? 3 genera AKA |
Fungal infection
Grows on keratin 1. trichophyton 2. microsporum 3. epidermophyton AKA ringworm |
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Types of ringworm (dermatophyte)
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tinea captis
-ringworm of scalp tinea pedis -athlete's feet tinea crurls jock itch tinea ungulum nail onychomycosis |
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Diagnosis of Dermatophyte (ringworm)
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signs and symptoms (athlete's food)
Microscopy of skin scrapings for line of spores hyphae (at room temp is hyphae) Culture which takes weeks |
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Treatment of Dermatophytes
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topical non prescription (start at topical)
-miconazone, clotrimazole, not effective on hair oral -griseofulvin, ketoconazole |
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Candidasis
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Fungal skin infections
Candida albicans -opportunistic infections 1. 2nd to antibiotic therapy 2. change in ph skin cutaneous- thrush (around mouth) or vaginitis |
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Epidemiololgy of Candidiasis
-Groups at risk |
1. infants- thrush
2. aids patients 3. obese-increased moisture 4. diabetics because of decreased circulation |
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Diagnosis of Candidiasis
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signs and symptoms
Culture: german tube |
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Treatment of Candidiasis
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topical miconazole, clotrimazole, takes yeast and tells species based on color
systemic infections with oral ketoconazole with antifungals |
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Scabies
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Parasitic infection
Caused by mite sarcoptes scabies -burrow under skin to lay eggs -causes itching and inflammation -transmitted by intimate (sexual included) -500,000 a year seek treatment |
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Treatment of scabies
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various insecticides
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Symptoms of scabies
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2-6 weeks after initially infected because your immune system which is thought to produce the symptoms of itchiness associated with scabies, needs time to react to infection
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How long if previously infected will it take to begin to show signs of infection?
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48 hours
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Symptoms of scabies
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immense itchiness and tend to be worse after shower at night,
red blotches and lines of skin caused by burrowing into skin |
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Treatment of scabies
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insecticides
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Pediculosis (lice)
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parasitic infection
1. body lice (pedicures humans corporis) spreads endemic typhus, public lice (crabs) 2. Head lice (pediculus), human capitis |
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Lice disease
-requires what? |
Require blood from host
sensitization to louse saliva causes itching female lay eggs called nits(stuck to hair follicles) |
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Epidemiology of head lice
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very common school children disease
pubic lice is STD crabs |
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Treatment of pediculosis
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Nix or Rid over the counter insecticides
-resistance to those common -comb out nits with comb |
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Prevention of lice
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Thourough cleaning of bedding, hat, bruised, stuffed animals
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Leishmaniasis
-caused by ? spread by? - |
Caused by Leishmania sp
protozoan single cell, spread by sand fly affects about 12 million people globally SA, africa and middle east cutaneous or systemic |
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Gas gangrene
-gram stain -infection type? |
Bacterial would infection
clostridium perfringens gram positive rod spore former strick anaerobe any organism can cause wound infection |
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Gas gangrene disease
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degrades carbs to acid and gas through fermentation
H and Co2 bubles in tissue putting pressure on nerves, causing pain and cuts of blood flow causing ischemia and necrosis fatal if untreated antibiotics can't get to infection |
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Epidemiology of gas gangrene
Who gets it? |
1. improper abortions
2. wartime injuries 3. diabetes |
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C perfrigens virulence factors (Gas gangrene)
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metabolism-gas production
Toxin production alpha toxin and beta toxin (necrotizing toxin) |
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Diagnosis of gas gangrene
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Clinical signs (black color)
isolate bacterium and conduct toxin typing must use anaerobic culture techniques |
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Treatment of gas gangrene
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debridement of wound and amputation
penicillin Hyperbaric chamber passive antibody against alpha toxin specific for toxin Y |
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Prevention of gas gangrene
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clean and deride wounds, faster cleaned less chance of developing gas gangrene
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Pseudomonas Aeruginosa
Gram stain and where found? |
Aerobic gram - rod found in soil/water
strick aerobe |
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Infections cause by aeruginosa
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burn wounds (fluoresces)
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Epidemiology of pseudomonas aeruginosa
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opportunistic pathogen bc in dirt air
nosocomial infections in hospital VERY ANTIBIOTIC RESISTANT, hard to treat and control |
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Virulence factors for pseudomonas aeruginosa
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Exotoxin A
Dense biofilm in CF patients |
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Top causes of wound infections
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Staph aureus
Coag - staph Enterococci E. Coli Pseudomonas Aeruginosa |
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Ophthalmia neonatorum
Gram stain? Organism? |
Bacterial eye infection
neisseria gonorrhoeae gram - diplococci chlamydia trachomatis |
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Epidemiology of Ophthalmia neonatorum
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STD in adults, newborn infected during birth via infected birth canal
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Treatment of ophthalmia neonatorum
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instilled erythromycin instead of classically used silver nitrate
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Inclusion conjunctivitis
Organism? Where acquired? Treatment |
Chlamydia trachomatis
acquired in swimming pool, resolves itself and can scar young adults Tetracycline drops to treat |
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Trachoma
organisms |
Chlamydia trachomatis: small obligate intracellular parasite
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#1 preventable cause of blindness in world
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Trachoma
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Trachoma disease
What is it? Lead to? Formation? |
Chronic inflammation of cornea and conductive
Leads to trichiasis-eyelashes turn inward cause corneal scarring and pans Panus formation gets into cornea can cause permanent blindness |
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How is trachoma transferred?
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Carries from person to person on flies, towels, clothes,
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Chlamydias odd life cycle
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Obligate intracellular bacteria cannot complete life cycle out of cell.
Elementary body is infectious reticulate body noninfectious but metabolically active in this form (gives symptoms) replicate in cytoplasm of host cells can't gram stain cyst is EB and troph is Rb |
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Epidemiology of trachoma
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north africa, native americans appalachia
worldwide 500 million cases per year and 2 million go blind |
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Transmission of trachoma
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hand contact
shared towels flies |
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Treatment of trachoma
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tetracycline ointment
surgery to prevent eyelash abrasion |
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Prevention of Trachoma
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Higher living standards
Better sanitary practices Health education don't let flies near eyes |
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Conjunctivitis (pinkeye)
Organisms |
Strep pneumoniae
Haemophilus influenzae Staph aureus Pseud sp Viral conjunctivitis also (not pus filled) contact lenses increase prevalence |
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Herpes Keratitis
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Viral infection of eye
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