Lec23 ID of the Skin Flashcards
What is folliculitis?
- inflammation of hair collicle
- get itching
What are the causes of folliculitis?
- gram positives: staph, strep
- gram negatives: pseudomonas “hot tub” folliculitis
- fungal: pityrosporum
- mechanical occlusion [collect debris viewed as foreign, get inflammation
What is the treatment of bacterial or mechanical folliculitis?
- topical mupicorin
- oral antibiotics [cephalexin, doxycyclin]
- shower after exercise
- keep skin dry
- wear loose clothing
What is treatment of fungal folliculitis?
- topical antifungals [ketoconazole]
What is an abscess?
- walled off space with pus, usually infected and painful
What is a furuncle?
furuncle = boil
- walled off fluctuant mass encolsoing pus that evolved from superficial folliculitis
What is a carbuncle?
group of coalesced furuncles
What causes skin absesses?
usually staph aureus
- also can be anaerobe, gram neg, or fungus
What is treatment for furuncle/carbuncle?
- incise and drain and culture pus
- warm soak
- antibiotics
- intralesional steroid injection
What are normal antibiotics for treating furuncle/carbuncle?
cephalexin orally AND mupirocin topically
What is skin sign of MRSA?
- furunculosis
- can evolve in large ebsesses, cellulitis, or necrotic plaque
What is treatment for MRSA skin infection?
binor: bactrim, doxycycline, clindamycin
severe: vancomycin
What is impetigo?
- superficial skin infection
- can be bullous or non-bullous
- starts around bug bite, pimple, eczema etc
- honey colored crust, weeping, oozing
What are causes of impetigo?
- staphylococcus aureus
- streptococci [often colonize nose]
What is treatment for impetigo?
- mupirocin
- may also need oral antibiotic for severe disease
What is important sequelae of impetigo?
post strep glomerulonephritis[ BUT NOT ARF]
What is cellulitis?
- infection of dermis and subcutis [fat], due to break in skin, usually bacterial
What causes cellulitis commonly?
most commonly: staph aureus, group A strep
- can be any organism
What are the 4 signs of cellulitis?
- rubor [erythema]
- dolor [pain]
- calor [heat]
- tumor [swelling/edema]
How do you diagnose cellulitis?
primarily just clinically
What is treatment for cellulitis?
antibiotics
if in lower extremity –> elevate leg to minimize edema and increase drug distribution to target
What is erysipelas?
superficial bright red cellulitis with lymphatic involvement
- more sharply demarcated than regular celluliits
What is common cause of erysipelas?
group A streptococci
How is erysipelas diagnosed?
usually based on clinic
what is treatment for erysipelas?
oral antibiotics [penicillin]
What is cause of scarlet fever?
streptococcus pyogenes [group A strep]
- usually due to pyrogenic exotoxin after pharyngeal infection
What are signs of strep pyogenes?
after 2-4 days get:
- acute pharyngitis
- diffuse eryhtmeatous rash that spares face, palms, sole
- pastia’s line: petechial lines in skin folds
- strawberry tongue
- skin rash fades with desquamatoion
- fever, malaise, headahce,
How is scarlet fever diagnosed?
positive throat culutre for s. pyogenes + clinical symptoms
what is treatment for scarlet fever?
normally:: penicillin or amoxicillin
can also use: cephalosporins, macrolide
What are signs of necrotizing fasciitis?
- rapidly progressive necrosis of subcutaneous fat/fascia/muslce
- begins with area of tenderness, erythema, warmth, swellin
- quicky progression
- skin changes from red & purple to gray-blue
water, bad smelling fluid - life threatening need emergency surgery
What are causes of necrotizing fasciitis?
- streptococci
- polymicrobial
How do you diagnose necrotizing fasciitis?
- MRI to look for gas and soft tisuse involvement
What is treatment for necrotizing fasciitis?
- early and aggressive debridement
- IV broad spectrum antibiotics
What is cause of menigococcemia?
neisseria meningitidis = gram negative diplococci
= derm emergency must notify state dept of health
What are signs of meningococcemia?
- meningitis
- septic shock
- slate-gray purpura/ecchymosis signaling DIC
What is therapy for meningococcemia?
- droplet isolation
- penicillin G
What do you use for prophylaxis of contacts to meningococcemia?
rifampin, cirpofloxacin
What is cause of lyme disease?
borrelia burgdorferi from bites of ixodes [deer tick]
What are 3 stages of lyme disease?
- erythema chronicum migrans = circle shaped rash
- carditis [AV block] and bell’s palsy
- arthritis
What is treatment for lyme disease?
doxycycline or amoxicillin
What is prophylaxtic treatment for lyme diease?
- insect repellent
- doxycline at time of tick bite
What are skin signs of primary, secondary, and latent syphilis?
primary: chancre –> painless
secondary: palsm/soles like erythema multiforme, papulosquamous like pityriasis roasea, mucous patch in mucosal surface, condyloma latum
What are skin signs in latent syphilis?
no rash
what are skin signs in tertiary syphillus?
- gumma [rubbery ulcerated nodule]
clinical: insect bite then redness and swelling around bite, spread up leg = red and swollen
what should you think?
cellulitis –> likely due to staph aureus, group A strep
clinical: 18 yo, fever, sore throat, malaise, generalized erythematous rash, strawberry tongue, sister recently treated with penicillin for sore throat
what should you think?
scarlet fever –> strep A [pyogenes]
diabetic with necrotic area on anterior thigh, foul smelling?
what should you think?
necrotizing fasciitis
due to strep or polymicrobial
18 yo with low grade fever, runny nose, headache, stiff neck, petechial rash
what should you think?
meningococcemia due to neisseria meningitidis
30 yo with sore throat, neck stiff, erythematous circular rash on back, EKG incomplete right bundle branch block, just got back from hamptons
what should you think?
lyme disease due to borrelia burgorferia via bite of ixodes deer tick
clinical: 1 wk history of painless penile lesion, condom use intermittent, no fever, chills, dysuria, nontender adenopathy
what should you think?
syphilis due to terponema pallidum
What are signs of early and late congenital syphilis?
early: first two yrs have rhinitis
late: untreated get cutaneous, dnetal, skelatal, deafness
How do you diagnose syphilis?
- dark field microscopy
- RPR [for acute infection]
- FTA-Abs [pos for live]
What is treatment for syphilis?
- penicillin
- HIV test
- alert sexual contacts and state dept
What is salmonellosis?
- infection by G-aerobic bacilli in genus salmonella
What is typhoid fever? how is it spread?
enteric fever due to S. typhi
- via direct contact with persons with typhoid fever
what is paratyphoid fever? how is it spread?
enteric fever by non-typhoidal strains [s. paratyphi]
- from inadequately cooked poultry or eggs
What are signs of salmonellossi?
rose spots = red blanching macules and papules on chest and abdomen in groups
fever
GI symptoms
How do you treat salmonellosis?
- ceftriaxone
- quinolones
