Dermatology Flashcards
Etiology for Tinea Capitis
-Trichophyton tonsurans -Microsporum canis
Epidemiology for Tinea Capitis
Age: Childhood infection Ethinicity: African American Other: personal hygiene, over crowding, asymptomatic carriers
How is Tinea capitis acquired
-Direct contact -Fomites
How does Tinea Capitis present
-Scaly patches w/ Alopecia -Patches of alopecia w/ black dots -Wide spread scaling w/ subtle hair loss -Kerion -Flavus
DDx for Tinea Capitis (6)
-Seborrheic dermatis -Contact dermatitis -Pustular/plaque psoriasis -Atopic dermatitis -Alopecia areata -Trochotillomania
How is Tinea Capitis evaluated (5)
-Physical exam -KOH prep -Woods light -Culture -Dermosocopy
How is Tinea Capitis treated (3)
Griseofulvin x6-12wks (mirosporum) Terbinafine x2-4wks (trichphyton) Itraconazole x4-6wks or Fluconazole x8-12wks
Etiology for Tinea Corporis
-T. rubrum -Epidermophyton floccosum, T. interdigitale, M. canis, T. tonsurans
Epidemiology for Tinea corporis (4)
-Caregivers w/ children -Athletes (Tinea gladiatorum) -Immunocompromised -Pets
How does Tinea Corporis present
Pruritic annular erythematous plaque with central clearing and advancing border
DDx for Tinea corporis (5)
-Erythema annulare centrifugum -Granuloma annulare -Nummular eczema -Psoriasis -Tinea versicolor
How is Tinea corporis evaluated (3)
-Hx and physical exam -KOH prep -Culture
How is Tinea corporis treated
-Topical antifungals (-azoles) x2 *Avoid Nystatin -Systemic: Terbinafine, Fluconazole, Itraconazole PO
Why shouldn’t you give steroids to treat Tinea corporis (5)
-Doesnt work -Changes appearance of lesions -Majocchi’s granuloma -Skin atrophy -Expensive
Etiology for Tinea Cruris (Jock itch)
-T rubrum and E floccosum -T interdigitale -T verrucosum
Epidemiology for Tinea cruris
-Autoinnoculation from tinea pedis -Men>women -Skin folds
How does Tinea cruris present (5)
-Well marginated annular plaque w/ scaly raised border. -Extends from inguinal fold -Pruritis and pain -Scrotum spared -Chronic and progressive
DDx for Tinea cruris (8)
-Erythrasma -Cutaneous candidiasis -Candida intertrigo -Contact dermatitis -Psoriasis -Sehorrheic dermatitis -Lichen simplex chronicus -Folliculitis
How is Tinea cruris evaluated (3)
-Hx and physical exam -KOH prep -Culture
How is Tinea cruris treated
-Topical antifungals -Resitant: oral Griseofulvin -Treat Tinea pedis -Lifestyle (no tight clothing or hot baths)
Etiology for Tinea pedis
-T rubrum, T interdigitale, E floccosum
Epidemiology of Tinea pedis
-Most common dermatophytosis -Occlusive footwear, communal showers/pools
How does acute Tinea pedis present
-self-limited, intermittent, recurrent -Itchy/painful vesicles after sweating -Secondary staph infection -Cn cause dermatophytid reactions
How does chronic Tinea pedis present
-Slowly progressive -Erosion/scales between toes -Interdigital fissures -Moccasin ringworm -Sharp demarcation with scales in creases
DDx for Tinea pedis
-Eczema -Psoriasis -Bacterial co-infection -Interdigital erythrasma -Dyshidrosis -Contact dermatitis
How is Tinea pedis evaluated
-Hx and exam -KOH prep
How is Tinea pedis treated
-Topical antifungal x4wks -Terbanifine, itraconazole, Fluconazole for chronic disease -Burrows wet dessing, 20min BID/TID -Lifestyle (foot powder, proper footwear)
Etiology for Onychomycosis
-T. rubrum -T. mentagrophytes -Candida albincans -Nondermatophyte mold
Epidemiology for Onychomycosis
-Dermatophyte (toenails) -Yeast (fingernails) -Non-dermatophyte molds -Risk factors; age, tines pedis genetics, immunodeficiency, household infection
How does distal subungual Onychomycosis present
-Starts with great toe. Discoloration at distal corner toward cuticle Distal end of nail breaks to expose nail bed
How does proximal subungual Onychomycosis present
-Starts near the cuticle Seen in severely immunocompromised (AIDS)
How does white superficial Onychomycosis present
-Dull white spots on the surface of nail plate and spread centrifugally
How does yeast Onychomycosis present
-Thickening of fingernail with brown/yellow discoloration. May cause paronychia
DDx for Onychomycosis
-Psoriasis -Eczematous conditions -Onychogryphosis -Lichen planus -Iron deficiency
How is Onychomychosis evaluated
-KOH prep of nail scrapings -Culture -Biopsy
How is Onychomycosis treated
-Oral Terbinafine (6wks fingernails, 12wks toenails) or Fluconazole/Itraconazole (for both dermatophyte and nondermatophyte)
Another name for Atopic dermatitis is?
Atopic eczema
What are the characteristics of dematitis/eczema
-Pruritis -The itch that rashes -Begins early in life -Chronic
What is the Atopic triad
-Atopic dermatitis -Allergic rhinitis (hay fever) -Asthma
How does Eczema present
-Ill-defined erythematous scaling patches to edematous papules and vesicles -Children; cheeks, scalp and extensor surfaces -Adults; flexor surfaces, hands/feet
How is dermatitis diagnosed
Based on clinical presentation (pruritus, eczema, Hx, early age of onset, Xerosis-dryskin)
What is DDx for Eczema
-Nummular dermatitis -Seborrheic dermatitis -Scabies -Contact dermatitis -Tinea infections -Cutaneous T cell lymphoma
How is eczema treated
-Topical steroids (briefly) -Oral antihistamines prn for pruritis -Abx for secondary infection -Topical calcinerin inhibitors (Tacrolimus,P Pimercrolimus) -Avoid exposure to triggers -Use emollients
How does Lichen simplex chronicus present
-Dry leather appearance, hyper pigmented, exaggerated skin markings -On back of neck, wrists, forearms, lower legs, genitals
How is Lichen simplex chronicus treated
-Stop itch-scratch cycle
Etiology for Dyshidrotic Eczema
-Dyshidrosis -Pompholyx
how does Dyshidrotic eczema present
-pruritic deep vesicles with tapioca like appearance -on hands, sides of fingers, palms, soles
How is Dishydrotic eczema treated
-Wet dressings -Topical steroids
What happens in Keratosis pilaris
disorder of keratinization that forms horny plugs in hair follicles
How does Keratosis pilaris present
Rough raised flesh colored/red/brownish papules -On upper arms, thighs, cheeks, upper back
How is Keratosis pillars treated
-Creams -Exfoliating scrubs -Topical retinoids -Salicylic acid/alpha-hydroxy acid
How does allergic contact dermatitis present
??
How is contact dermatitis treated
-Bacitracin ointment (avoid neomycin) -Avoid allergenic agents(Ni, Latex, Poison oak/ivy, preservatives) -Emollient -Topical steroids
What is the cause of irritant contact dermatitis
-Occupational -repeated friction -Chemicals
Etiology for seborrheic dermatitis present
Malessezia furfur
Epidemiology of seborrheic dermatitis
-Infants, teens, adults
How does seborrheic dermatitis present
Infants: yellow greasy adherent scales on vertex of scalp, diaper area, axillary skin Adults; greasy scales and yellow macules, patches, papules on scalp, face,ears
DDx for seborrheic dermatitis
-Rosacea -Psoriasis -Perioral dermatitis -Rash of SLE
How is seborrheic dermatitis treated
-Selenium sulfide/anti-dandruff shampoo -ketoconazole shampoo/cream -Mild topical steroids
Etiology of Pityriasis rosea
unknown - viral
How does Pityriasis rosea present
-Exanthem; herald patch on trunk w/ secondary patch in 2wks, may or may not be pruritic -Oval papules/plaques with christmas tree pattern -Trunk and proximal extremities
DDx for Pityriasis rosea
-Tinea corporis -Tinea versicolor -Guttate psoriasis -Nummular eczema -Drug eruptions -Secondary syphilis
How is Pityriasis rosea treated
-Self limiting -Loratidine (Claritin) 10mg PO x1 daily, Cetirizine (zyrtec) 10mg PO x1 daily, DIphehydramine (benadryl) 25-50mg PO q6hrs PRN -Med strength topical corticosteroids
Epidemiology of Lichen planus
-Middle aged adults
How does lichen planus present
-4Ps(purple, pruritic, polygonal, papules) -Wickham’s striae visible (white lines) -Affects wrists, back, shins, scalp, penis, mouth
How is lichen planus treated
-Topical/oral intralesional steroids -Cyclosporin
Etiology of Psoriasis
-2% of western popn -Peaks at 15-30 and 50- -Hereditary component -Infections (strep) -Drugs -Stress/injury
How does Psoriasis present
-Thickened red plaques with silvery scale -Pitted nails (onycholysis), arthritis -On extensor surfaces -Koebner phenomenon-plaques in areas of skin injury(rubbing, scratching)
How do you evaluate Psoriasis vulgaris evaluated
-Auspitz sign (remove scale=punctate bleeding)
What are the morphological variants of Psoriasis
-Vulgaris(chronic plaque) -Guttate (small drop like plaques) -Inverse/flexural -Palmar-plantar -Generalized pustular -Nail
DDx for Psoriasis
-Seborrheic dermatitis -Nummular eczema -Candidiasis -Tinea corporis/capitis -Mycosis fungoides -Psoriasiform drug eruptions
How is Psoriasis treated
-Depends on pattern and severity -General measures (sunshine, baths, emollients, occlusive dressing, rest) **Do not use oral steroids** -Topical (Anthralin, Ultra high potency steroids, calcipotriol, tazarotene, coal tar, calcineurin inhibitors) -Phototherapy (UVB/UVA) -Systemic (Methotrexate, Biologics)