Viral, Bacterial, & Parasitic Skin Infections Flashcards
What are the s/s of condyloma acuminata (genital warts)?
Tiny, painless papules
Evolve into soft, fleshy cauliflower-like lesions (ranging from skin colored to pink or red)
How & where does condyloma acuminata occur?
Occurs in clusters in the genital regions & oropharynx
How do you dx mucosal HPV?
Whitening of lesion w/ acetic acid application
How do you treat condyloma acuminata?
chemical, salicylic acid, cryotherapy, laser & podophyllin
What are the s/s of herpes simplex virus 1 & 2?
Prodromal sx 24hrs prior (burning, paresthesias, tingling) –> painful, grouped vesicles on an erythematous base
What are the s/s of acute herpetic gingivostomatitis?
Sudden onset fever, anorexia –> gingivitis, vesicles in mouth, tongue, & lips –> grey/yellow lesions
What are the s/s of acute herpetic pharyngotonsillitis?
Vesicles rupture –> ulcerative lesions w/ grayish exudates in posterior pharynx
What are the s/s of herpes labialis?
Cold sore, fever blister w/ stress/illness
How do you diagnose HSV?
PCR = most sensitive/specific test
Tzanck smear
How do you treat HSV?
Acyclovir, valcyclovir, famiciclovir
What viral family does molluscum contagiosum belong to?
Poxviridae
What are characteristics of molluscum contagiosum?
Highly contagious
MC in children, sexually active adults, pts w/ HIV
What are s/s of molluscum contagiosum?
Single or multiple dome-shaped, flesh-colored to pearly-white, waxy papules w/ central umbilication
How do you treat molluscum contagiosum?
No tx needed
Curettage, cryotherapy, podophyllotoxin.
Topical retinoids if severe
How do you treat verruca (warts)?
Most resolve spontaneously within 2 yrs
Topical salicylic acid & plasters
Cryotherapy, electrocautery, CO2, laser, bleomycin
How is varicella zoster virus (HHV3) transmitted?
Respiratory droplets, direct contact
What are the s/s of varicella (chicken pox)?
Fever, malaise, pruritis
Clusters of vesicles on an erythematous base “dew drops on a rose petal” in different stages*
Begins on face, trunk –> extremities
What are the s/s of herpes zoster (shingles)?
VZV reactivation along 1 dermatome of the dormant virus in the spinal root & CN ganglia
What are the s/s of herpes zoster oticus (Ramsay-Hunt Syndrome)?
Facial nerve (CN VII) - otalgia, lesions on the ear, auditory canal & TM, facial palsy
Auditory sx: tinnitus, vertigo, deafness, ataxia
How do you treat the chicken pox?
Symptomatic tx
How do you treat the shingles?
Acyclovir, valacyclovir, famciclovir (given within 72 hrs to prevent PHN)
How do you treat Ramsay Hunt Syndrome?
oral acyclovir + corticosteroids
What causes cellulitis? How does it occur?
MC caused by S. aureus & GABHS/S. pyogenes
Occurs after a break in the skin
What are s/s of cellulitis (locally)?
Macular erythema (not sharply demarcated), swelling, warmth, & tenderness
What are s/s of cellulitis (systemically)?
Not common
Fever, chills, +/- tender lymphadenopathy, myalgias, vesicles, bullae, hemorrhage & necrosis
How do you treat cellulitis?
Cephalexin, dicloxacillin x7-10days
Clindamycin or erythromycin if PCN allergic
MRSA: IV vanco or linezolid, oral TMP-SMX, doxycycline, daptomycin
What causes erysipelas?
GABHS
What are s/s of erysipelas?
Well demarcated margins of cellulitis, intensely erythematous (St. Anthony’s fire)
MC involves the face or skin w/ impaired lymphatic drainage
How do you treat erysipelas?
IV PCN
Vanco (if PCN allergic or MRSA suspected)
Describe vasculitis
See pages 63, 220-223, 340, 343, 438 of PANCE Prep Pearls
What are RFs for impetigo?
Warm, humid conditions
Poor personal hygiene
Where does impetigo occur on the body?
Sites of SF skin trauma, primarily on face & extremities
What does nonbullous impetigo look like?
Vesicles, pustules –> “honey-colored crust”
MC type, a/w lymphadenopathy
What bacteria causes nonbullous & bullous impetigo?
S. aureus MC
What are the s/s of bullous impetigo?
Vesicles –> large bullae –> rupture –> thin “varnish-like crusts”
Fever, diarrhea
What does ecthyma impetigo look like? What bacteria causes it?
Ulcerative pyoderma
GABHS
How do you treat impetigo?
Topical mupirocin (bactroban) = DOC! x 10 days
Bacitracin. Good hygiene.
If extensive or sx persist –> Cephalexin, dicloxacillin, macrolides
How are scabies transmitted?
Mites are transmitted through prolonged, skin-skin contact or fomites
Burrow into skin to lay eggs, feed, & defecate
What are s/s of scabies?
Intensely pruritic lesions (papules, vesicles, & linear burrows). Increased at night
Commonly found in the intertriginous zones (web spaces btwn fingers/toes, scalp, scrotum, glans, penile shaft, body folds)
Usually spares the neck/face
How do you diagnose scabies?
Clinically!
Skin scrapings of the burrows w/ mineral oil
How do you treat scabies?
Topical permethrin = DOC! Applied from neck to the soles of feet for 8-14hrs before showering. Repeat application after 1 week.
Lindane (cheaper): DO NOT USE AFTER BATH/SHOWER –> SEIZURES!! Also teratogenic (DO NOT USE IN PREGNANCY, BREASTFEEDING, or CHILDREN<2)
What are s/s of pediculosis (lice)?
Intense itching (esp occipital area), papular urticaria near lice bites
Nits: white oval shaped eggs at base of hair shafts
How do you treat pediculosis?
Topical permethrin = DOC! x 8-10 hrs
Capitus: permethrin shampoo x 10mins
2nd line: Lindane (S/E = neurotoxic)
