Common Infections of the Skin Flashcards
HSV 1 and 2
Grouped vesicles on an erythematous base
Persists in sensory ganglia leading to recurrent infections
Can see erosions and crusting sometimes
Varicella
Morphology like “a dewdrop on a rose petal”
Initial lesions papules which become vesicles
Vesicles then crust over
May heal with scarring
Crops of lesions in all stages
Herpes zoster
Prodrome of neuritic pain
Acute vesicles then crusted papules
Distribution is unilateral and dermatomal
Grouped vesicles on an erythematous base
Non bullous impetigo
Scaling honey crusted non bullous impetigo
Superficial infection of epidermis caused by group A strep or s aureus
Bullous impetigo
Vesicles and bullae
Clear or slightly yellow fluid
Shallow erosions if bullae break
Caused by S aureus
Bedbugs
Cause erythematous papules, vesicles, nodules
Will often bite on body and head and neck area
Itchy
Groups of 3 or 4
Pityrosporum folliculitis
Monomorphous papules without comedones
Sweaty people
Caused by normal healthy yeast that has gone into the hair follicle
Not very inflamed
Pseudomonas folliculitis
History of hot tub exposure
Inflammatory follicular-based papules and pustules
Involves exposed areas
Self limited
Tinea corporis
Annular scaling edge
Well demarcated plaques
Central clearing
Single or multiple lesions
Pityriasis versicolor
Not a dermatophyte infection
Well marginated round scaling brown or pale minimally elevated papules
Yeast
Common in young adults
Secondary syphilis
2-6 months after primary infection
First eruption is macular then can be papulosquamous, pustular or acneiform
Look for involvement of palms and soles
Verruca vulgaris
Common warts
Firm, hyperkeratotic papules with clefted surface and vegetations
Red or brown dots from thrombosed capillary loops
Transmitted by skin to skin contact
Molluscum contagiosum
Skin coloured umbilicated papules
Mollusca undergoing spontaneous regression may have an erythematous halo/ezcema
Scabies
Widespread pruritic eczematous eruption
Spares head and neck usually
Can take 6 weeks from exposure
Burrows: serpiginous track with spot at end
Nodules: red/brown nodules in axillary area and groin, can persist after infection is clear
Norwegian scabies
Heavy infestation of scabies mite in immunocompromised hosts
Highly contagious and requires repeated treatments
Pediculosis corporis
Body louse
Eczematous eruption
No primary lesions
Secondary infection common
Look in seams of clothing for louse and nits
Very itchy - a lot of crusting and superficial erosions
Pediculosis Capitis
Head lice
Itchy
Bite reactions include eczema, excoriation, lichenification
Tinea cruris
Well marginated scaling red plaques with central clearing
Papules and pustules may be present at margins
Occurs in inguinal region and on thighs
Candidal intertrigo
Erythematous plaques with satellite papules and pustules
Found in moist environment
From yeast
Erythasma
Sharply marginated patch
Redilection for folds
Inverse psoriasis
Well marginated erythematous plaques
Check for psoriasis elsewhere (scalp, nails, etc)
Tends not to scale like psoriasis elsewhere
Things that Staph aureus can cause
Impetigo Ecthyma Cellulitis Folliculitis Furuncles (boils) Carbuncles Abscesses
Things HPV can cause
Flat warts Plantar warts Verruca vulgaris Periungual warts Condylomata
Tinea unguium
Thick yellow dystrophic toenails or fingernails
Toes more often involved
Genetic predisposition
Often associated with tinea pedis
Tinea pedis
Athlete’s foot
Interdigital (scaling, maceration, fissures) and moccasin (well marginated, fine scale, hyperkeratosis) types
Inflammatory or bullous types
