Workshop: Skin Infections Flashcards
two broad groups of fungi:
yeast and mold
Mold spores germinate to produce ____ _____=
hyphae
• ____ infections
• Tinea corporis, tinea capitis, tinea pedis,
onychomycosis
Mold spores germinate to produce branching filaments=
hyphae
• DERMATOPHYTE infections
• Tinea corporis, tinea capitis, tinea pedis,
onychomycosi
• Yeasts are solitary rounded forms that reproduce by
making more rounded forms (____/____)
• CANDIDA
• Yeasts are solitary rounded forms that reproduce by
making more rounded forms (budding/fission)
• CANDIDA
what is the morphology
- irreuglar annular border with central clearing. its a large and riased plaque with a roled/scale border.
probably a tinea infection
what is the morphology
hyperpifmented plaque with some raising along peripheral border.
central clearing, probably tinea
athletes foot; tinia pedis
t/f tinea corporis and pedis treatment requries combination treatment with topical corticosteroid and anti-fungal
false. corticosteroids clears fungus from top surface but makes the fungal infection grow deeper into thes kin. loses its central clearing–makes it harder to diagnose.
- Treat a fungal infection with topical antifungal
- Treat cutaneous inflammation (eczema, psoriasis) with topical corticosteroid
• When you don’t know- do a fungal scraping, bacterial swab and/or
take a skin biopsy!
majocchi’s granuloma
Treating tinea corporis with a topical steroid
Erythematous Plaque Loses its advancing border
tinea
ddx
onychomychosis; accumulation of fungal contents underneath the nail bed and causes separation.
could be psoriasis
morphology
located on skin folds
erythematous papules coalescing into patches
satellite lesions
candida intriga or diaper rash
candida intriga
• Focus on the bright erythematous patches WITH satellite
erythematous papules • These satellite papules = candida infection
treatment with diaper dermatitis
its a very common to have secondary candidal infection
- keep the area as dry as possible
- change diaper frequently; especially afer poo
- use barrier cream
- use topical antifungal if candida suspected
morphology
crusting
erythematous papules coalescine together to form blistering erythematous plaques
probably impetego
crusting
erythematous papules coalescine together to form blistering erythematous plaques
probably impetego
crusting
erythematous papules coalescine together to form blistering erythematous plaques
probably impetego
- kind of looks like psoriasis
bacteria that causes impetigo and mechanism
staph aureus causing local production of exfoliative toxins, separting the keratinocytes within the granular layer. same as in pemphigus (autoantibodies target demosomes)
- it’s contagious; person to person or fomite contact
- infection usually occurs of site of scratching (insect bites, atopic derm)
baterial folliculitis
lesion caused by bacterial folliculitis
furuncle= entire hair follicle and surrounding tissue involved.
- multiple = carbuncle.
treatment for bacterial folliculitis
superficial: antibacterial washes with benzoyl peroxide, topical antibiotics.
- widespread or recurrent- oral beta-lactam antibiotics, tetracyclines or macrolides.
carbuncle: larger pustules coalescing onto an inflammatory plaque.
several follicles infected.
• Tx: warm compresses, incision and DRAINAGE, systemic antibiotic
therapy if drainage not possible
• MRSA common
cellulitis
what layers are affected by cellulitis
deep dermis and subcutaneous tissue causing erythema swelling warmth and tenderness with ill-defined borders
4 key signs of inflammation/infection
- rubor
- calor
- dolor
- tumor
which bacterias cause cellulitis
• GAS or staph aureus (diabetic often mixed gram pos, neg, anaerob)
cellulitis
t/f you should prescribe antibiotics for lower leg lredness and swelling
false. Cellulitis is very rarely bilateral– must rule out other causes
primary morphology
grouped/clustered vesicles. indicative of viral infection
groups of clustered vesicles that are now pustules. probably started as a viral infection, then became secondary impetigenized (secondary staph infection)
HSV1, 2, 3.
1= oral
2= genital
3= varicella zoster
where is latency of hsv virus “stored”
sensory ganglia. Virus replicates at site of infection, travels to the dorsal root ganglia
where it becomes latent (exist in non-infectious state in host = evades
detection)
symptomatic primary infection symptoms
• gingivostomatitis in children or pharyngitis and mono-like syndrome in young adults-
mouth, lips, buccal mucosa, gingivae
• Painful erosive balanitis/vulvitis, often involve cervix, buttocks, perineum, dysuria, aseptic meningitis in 10% of females, urinary retention, extragenital lesions
what is eczema herpeticum
occurs in someone with barrier disruption in the skin = atopic dermatitis.
- widespread disseminated of HSV1 ( or 2) across affected skin.
eczema herpeticum
eczema herpeticum
what are dermatomes
an area of the skin supplied by nerves from a single spinal root
juicy vesicles and papules with a clear demarkation evident.
shingles
shingles
shingles
treatment of Zoster
- begin antiviral treatment within 72 hours optimally (but up to 7 days after is still beneficial)= earlier is better
• Acyclovir, famciclovir and valacyclovir are FDA approved
• Decrease severity and duration of skin lesions and pain • IV acyclovir for immunocompromised and those with serious complications
most common complication of shingles
Postherpetic neuralgia = Damage to the sensory nerves following
zoster infection, resulting in burning, debilitating pain > 3 months
after shingles episode
describe the morphology
vesicles on an erythematous base. DEW DROPS ARE CHARACTERISTIC CHICKEN POX
primary varicella infection
-
whats goin on
erythematous papules
- umbilization = ciruses
- not pustules = not yellow– not vesicles cause they are not fluid filled
MOLLUSCUM CONTAGIOSUM POXVIRUS
treatment for molluscum
- watchful waiting, most resolve on own in months to years
BUT it doesn’t look really good. topical; cantharidin, podophyllin cream, cryotherapy, curettage etc.
HPV
HPV; pedunculated on shaft of penis
t/f palmar or plantar warts are oncogenic
false. ones that are cerivcal, anogenital warts cause squamous cell carcinoma
how does HPV infect the host
it’s sneaky. HPV evolved to evade immune surveillance. There is no viremic phase during life cycle so avoids systemic immune response.
• 2/3 warts spont regress in 2 years and lesions of multifocal infections often
regress concomitantly
scabies
scabetic nodules of the genitals. erythematous papules
scabies treatment
MAKE SURE YOU TREAT ALL FAMILY MEMBESR
furuncle due to bacterial folliculitis
yeast/candida = moisture and heat causing candida intertrigo
scabies
shingles on a specific dermatome
erysipelas- superficial variant of cellulitis affecting dermis with lymphatic involvemnet vs cellulitis
GAS
- check for recent strep infection and treat with penicillin
