Infectious Skin Diseases Flashcards
type of wart caused by HPV 1 and 2; transmission of person to person or contact with contaminated surfaces; common in kids; hyperkeratotic, exophytic (dome-shaped) papules and plaques with scattered black dots (thrombosed capillaries); common on HANDS; many regress with time but takes 1-2 years
Verruca Vulgaris (common warts)
virus associated with many warts; transmitted by skin-skin contact or through contaminated surfaces/objects; infects basal keratinocytes of epithelium
HPV
type of wart caused by HPV 3 and 10; skin-colored to pink/brown minimally elevated papules with smooth flat top; common on hands, face, legs; easily spread by shaving
Verrucae Planae (flat warts)
type of wart caused by HPV 1 and 2; thick hyperkeratotic papules and plaques with black dots (thrombosed capillaries); common on palms or soles
Plantar warts
Treatment for warts (Verruca vulgaris, planae or palmoplantar)
Cryotherapy
Salicylic acid
type of wart caused by HPV 6 and 11; range from small smooth flesh-colored papules to large verrucous cauliflower-like plaque; on genitalia, perineum, and perianal
Condyloma Acuminatum (genital warts)
Treatment for genital warts
Cryotherapy, imiquimod, excision rarely
Flesh-colored papules with central umbilication caused by pox virus; very common in young children; spread by skin to skin contact usually; considered as STI if on genital skin in aults
Molluscum Contagiosum
Treatment for Molluscum Contagiosum
observe (self-resolve over time)
skin infestation with Sarcopetes scabiel (mites that live in s. corneum); multiple very itchy erythematous small papules, vesciles, patches of eczema; burrow in the webspaces; more common in GROUP settings (group homes, nursing homes, daycare); spread by DIRECT contact with infested person or fomite; incubation up to 6 weeks
Scabies
small area of grayish white scale where scabies has been moving
burrow in the webspaces
Mineral oil prep of a skin scraping helps diagnose
Scabies
Treatment for Scabies (dermal infection with burrows)
Medication: Permethrin cream or oral ivermectin
Wash all clothing and bedding with high heat drying of all family members
painful erythematous grouped vesicles on lips; spread by contact with bodily secretions containing the virus; primary infection 3-7 days after exposure with fever, malaise, and lymphadenopathy; viral latency in dorsal root ganglia
HSV I (cold sores)
reactivation of what virus can be triggered by stress, UV light, fever, trauma, immunosuppression; presents with localized pain and burning; shorter course than primary infection
HSV I (cold sores; labial herpes)
painful erythematous vesicles on genitalia; spread by contact with bodily secretions containing the virus; primary infection 3-7 days after exposure with fever, malaise, and lymphadenopathy
HSV 2 (genital herpes)
Treatment for HSV 2
acyclovir or valacyclovir
HSV infection of the finger; mostly seen in children
Herpetic Whitlow
Skin disorder caused by reactivation of VZV (human herpes virus 3) after chickenpox exposure in childhood; more common in elderly and immunocompromised; first sign is pain, then pink edematous papules in dermatomal distribution often on trunk, then evolve into vesicles/pustules with crusting
Herpes zoster virus (Shingles)
Pathology of herpes zoster will show
multinucleated giant cells
Tx for zoster
acyclovir or valacyclovir
Shingles put patient at risk for what?
post-herpetic neuralgia
Infection of the deep dermis and maybe subcutaneous fat; painful, warm to touch, spreading redness with fevers and chills; normally caused by Strep pyogenes or Staph. aureus (gram - if immunocompromised); almost always unilateral leg
Cellulitis
If both legs have cellulitis-like infection, what must be considered first?
Stasis dermatitis (bilateral cellulitis is very rare)
Well-defined bright red hot indurated (hardened) plaque with possible progression into vesciles/bullae; commonly caused by Strep. pyogenes infection of the superficial dermis with lymphatic involvement.; higher risk in pts with lymphedema or elderly
Erysipelas
firm, tender red nodule/abscess that involves a hair follicle
furuncle
firm, tender red nodule/abscess that involves several adjacent hair follicles
carbuncle
furuncle/carbuncle are most commonly due to
staph aureus; sometimes by MRSA
SUPERFICIAL bacterial skin infection of gram + cocci (Staph. aureus and Strep. pyogenes); erosions with honey colored crust; may be bullous or nonbullous; very contagious
Impetigo
Bullous impetigo due to staph aureus is caused by
exfoliative toxin that binds to desmoglein I (desmosome) and leads to acantholysis of upper epidermis
Treatment for Impetigo
Topical or oral antibiotics
Staph. aureus (group II) infection elsewhere and not at the skin sites with symptoms; exfoliative toxin leads to widespread superficial blisters and skin peels away in sheets; crusting and radial fissures around corners of mouth and eyes
Staphylococcal Scaled Skin Syndrome (SSSS)
Infection of the subcutaneous fat and fascia; violaceious to gray color indicative of necrosis; resembles cellulitis but pain is out of proportion; MEDICAL EMERGENCY; risk factors include diabetes, alcoholism, elderly, vascular disease, immunosuppression
Necrotizing Fasciitis
Treatment for Necrotizing Fasciitis
Debridement ASAP and IV antibiotics
Dermatophyte (fungal) skin infection; “ringworm” usually affecting trunk and limbs; erythematous annular (central clearing) thin plaque with scaly border; transmitted by close contact with infected human, animal, or fomites
Tinea Corporis
Tinea in general is more common in adults/kids
adults (except tinea capitis)
Treatment for Tinea Corporis
Topical antifungals (allylamines, imidazoles) or oral allylamine if extensive (terbinafine)
What can be seen on KOH prep that is used for diagnosis of Tinea corporis?
hyphae
fungal infection caused by Trichophyton rubrum; 3 different types
Tinea Pedis
type of tinea pedis; erythema and scaling on lateral surface of the feet
mocassin
type of tinea pedis with scaling in webspaces
Interdigital
type of tinea pedis with vesicles
inflammatory
Diagnosis and Tx for Tinea Pedis
same diagnosis (KOH) and treatment as tinea corporis
Which fungal infection is referred to as “athlete’s foot”
Tinea Pedis
Chronic dermatophyte fungal infection of the toe nail bed; respond POORLY to topical antifungals; need MONTHS of oral azoles or terbinafine; often seen with concurrent tinea pedis or tinea cruris
Onychomycosis
Dermatophyte infection of moist areas such as groin and inner thighs ; aka. jock itch
Tinea cruris
infection of the face with a dermatophyte fungus
Tinea facei
Fungal skin infection often caused by microsporum canis; causes fragility and breakage of the hair leading to multiple patchy ALOPECIA and black dot patches on scalp; reversible; 2 types
Tinea Capitis
type of tinea capitis in which spores coat the hair
ectothrix
type of tinea capitis in which spores are in the hair
endothrix
Treatment for Tinea Capitis
oral antifungals since TOPICAL INEFFECTIVE
What tinea is more common in kids than adults?
Tinea Capitis
candidiasis infection causing erythematous patch with occsional erosions in intertriginous areas (groin, armpits, buttocks, breasts, muffin-top)
Candidiasis (Intertrigo)
primary syphilis presents with
painless chancre (an ulcer on genitalia)
pink scaly papules that can occur anywhere on the body, especially on palms and soles; can imitate any skin disease; appears 3-10 wks after chancre; can cause moth-eaten alopecia
secondary syphilis
