derm infections Flashcards
How is cellulitis treated?
oral cephalosporins or penicillinase-resistent beta lactams for 10-14 days; IV abx for severe cases or bacteremia; linezolid or IV vancomycin for MRSA. diabetics should receive broad coverage becuase ofa n increased risk of multiorganism infection
what is a carbuncle?
a collection of multiple infected hair follicles causing an abscess
what parts of the skin are involved in hidradenitis suppurativa?
chronic follicular occlusion and apocrine gland (!!) inflammation that cuases recurrent abscess in the axilla, groin, and perineum
What are complications of hidradenitis suppurativa?
lare eroding facial abscess can cause cavernous sinus thrombosis
What pathogens most commonly cause necrotizing fasciitis? Common exam findings?
group A strep, or multipathogen infection of fascial planes
-warm swollen skin, loss of sensation in involved tissue, fever, crepitus, discoloration, bullae
What are causes of gangrene? What are the types of gangrene?
tissue necrosis due to poor vascular supply or severe infection.
dry gangrene: gradual necrosis of skin from vascular insufficiency, so skin is hard and dry
wet gangrene: necrosis due to acute vascular obstruction or infection causing blistering and swelling of involved area
When might you see subcutaneous air on Xray or CT?
wet gangrene, necrotizine fasciitis
What features suggest S. aureus vs. group A step for impetigo?
staph: vesicles/blisters
strep: pusutles
both are pruritic and have yellow crusted lesions
How should varicella be handled during pregnancy?
check varicella immunity in all pregnant women. varicella immune globulin should be given to all nonimmune pregnant women
What are complications of varicella virus that are seen among the immunocompromised?
encephalopathy or retinitis
How soon will the rash appear in chickenpox?
sx begin 2 wks after exposure; rash should develop within 3 days of HA, malaise, fever, myalgias
What is the course of chickenpox/shingles?
lesions may develop for up to 1 wk and resolve a few days after appearing. infective until lesions crust over
When is acyclovir given for varicella?
severe chickenpox, chickenpox or shingles in immunocompromised, trigeminal nerve shingles,
What are the labs for molluscum contagiosum?
giemsa and wright stains show large inclusion bodies
How is scabies treated?
permethrin cream or oral ivermectin. benadryl for itching. wash linens, clothes, etc in hot water
How is tinea versicolor diagnoesed and treated?
- Dx: KOH shows short hyphae and spores (spaghetti and meatballs), wood lamp shows extent of disease
- tx: oral ketoconazole for 5 days or topical antifungal
intertrigo: diagnosis and treatment
KOH prep shows pseudohyphae; give topical antifungal agent and topical corticosteroid
