Dermatology Flashcards
1
Q
Seborrhea dermatitis
A
- malassezia yeast, immunocop, bimodal (2-12mo, adolescence/early adulthood), M>F
- sxs: scaling erythema, itching, most common on scalp, face, chest, back, axilla, groin
- Infants: thick white or yellow greasy scale on scalp
- adults: flaky, greasy erythematous patches on scalp, nasolabial folds, ears, eyebrows, ant chest or upper back
- dx: mainly clinical, but bx may reveal parakeratosis, plugged follicular ostia, and spongiosis
- tx: topical ketoconazole, antifungal shampoo (selenium sulfide), zinc pyrithione twice/wk, irritation, topical steroids, calcineurin inhib second line, short term
- infants resolve spontaneously
2
Q
atopic dermatitis (eczema)
A
- more . susceptible to skin infxns, S. aurus (most common), associated allergic triad: asthma, allergic rhinitis, atopic derm
- onset before age 2, 10% diagnosed after age 5
- acute phase: vesicular, weeping, crusting eruption
- subacute: dry, scaly, red papules and plaques
- chronic: excoriations and lichenifiecation of skin, xerosis, hyperpigmentation, flexural lichenification in adults: anterior and lateral neck, eyelids, forehead, face, wrists, dorsa of feet, hands, facial and extensor involvement in children and infants
- dx: complications: secondary bacterial infxns - pustules and crusts
- tx: moisturizers or emollients: cetaphil or eucerin (ointments = aquaphor, patroleum jelly)
- bathing removes scale, crust irritants, allergens, limit use of nonsoap cleansers
- topical steroids = first line for flareups
- topical calcineurin for mod-severe (pimecrolimus/elidel or tacrolimus)
- abx to reduce flare ups
- UV phototx for severe or refractory
3
Q
nummular eczema
A
- one or several . coin-shaped plaques on extreities, typically on backs of hands
4
Q
dyshidrosis (pompholyx)
A
- occurs on lateral digits, clear, deep-seated erythematous “tapioca pudding” vesicles +/- scaling
- dx: history/clinical dx
- tx: topical steroids and emollients
5
Q
lichen simplex chronicus
A
- MC: adults, possible in children
- sxs: eczematous eruption caused by habitual scratching of single localized area, one or more plaques with lichenification in an area that is easily scratched
- tx: high potency topical steroids (first line) for all forms: clobetasol
- health maintenance: avoid scratching and picking at skin
6
Q
lichen planus
A
- chronic, inflammatory autoimmune dz, MC in perimen women 30-60yo, commonly associated with hep C
- sxs: acute onset, affects flexor surfaces of . wrists, forearms, legs
- 6 Ps: planar (flat topped), purple, polygonal, pruritic, papules, plaques, pruritis
- signs: Koebner phenomenon - follow lines of trauma, covered by lacy, reticular, white lines (wickham striae), postinflammatory hyperpigmentation as skin lesions clear, especially with darker skin
- dx: 4mm punch bx helpful and required for atypical dz
- tx: high potency topical steroids (first line) for all forms: clobetasol
- oral antihist, for itching, intralesional triamcinolone (kenalog) for hypertrophic lesions, topical calcineurin inhib (tacrolimus or pimecrolimus) for vulvovaginal lichen planus, 3-6wk oral prednisone for severe widespread cases
- prognosis: most self-limites: resolves spontaneously within 1-2y although recurrence is common
- screen for hep C
7
Q
pityriasis rosea
A
- children . and young adults, related to herpes type 7, not contagious, common on trunk, upper arms, and thighs
- sxs: begins w/ herald patch, pruritis, progress to generalized rash in 1-3wks, multiple salmon-pink oval papules scattered symmetrically, christmas-tree like distribution over neck, trunk, and proximal extremities, annular plaques with collarette scale
- tx: self-limiting (reassurance) in 6-8 wk without tx, antihistamines for itching
8
Q
Psoriasis
A
- etiology: genetic . and enviro factors, immune-mediated dz, MC form: plaque psoriasis
- RF: direct skin trauma (Koebner phenom), strep infxn, stress, smoking, obesity, ETOH
- sxs: distinctive red, scaling patches and papules that coalesce to form round-to-oval plaques on extensor surfaces, itchy and sometimes painful
- associated comorbidities: CV dz, lumphoma, depression
- dx: clinical, bx rarely needed
- tx: topical steroids, topical vitD, tazarotene for mild cases, calcineurin inhib such as tacrolimus or pimecrolimus, biologics for . severe, TNF inhib for sporiatic arthitis
- Pustular psoriasis: on palms and feet without plaques, can be severe and life-threatening
9
Q
erythema multiforme
A
- delayed-type hypersensitivity rxn to infxn or drugs, adults 20-40, infectious causes = HSV 1 or 2, M pneumo, fungal
- meds: barbiturates, hydantoins, NSAIDs, PCN, phenothiazines, sulfonamides
- sxs: acute, polymorphous eruption of macules, papules, and “target or iris lesions” without scaele = round shape, 3 concentric zones, itching or burning at site
- signs: sharply demarcated red or pink macules → papular → plaques , central portion becomes darker red, brown, dusky, or purpuric, crusting or blistering of center, symmetrically distrib, spreads distal to prox, minimal mucous memb involvement
- dx: <10% of body surface area
- tx: tx existing infxn or dc drug (mild = no tx; recurrent = acyclovir continuously)
- prognosis: resolves spontaneously in 3-5wks without sequelae, may recur
10
Q
Stevens-Johnson syndrome
A
- most often caused by meds, MC = sulfonamides (TMP-SMX), allopurinol, antipsychotics, antisiezure meds
- sxs: no typical target lesions, flat atypical targets, confluent purpuric macules on face and trunk, severe mucosal erosions at one or more sites
- dx: <10% of body surface area
- tx: stop meds immediately and transfer pt to burn center
11
Q
toxic epidermal necrolysis
A
- fever, mucocutaneous lesions, necrosis . and sloughing of epidermis (diffuse, macular rash with indistinct margins and central purpuric region followed by eventual formation of vesicles and bullae as epidermal necrosis develops over days; start on face . and spread inf to trunk and lower extrems), no typical target lesions, flat atypical target lesions, begins with severe mucosal erosions and progresses to diffuse, generalized detachement of epidermis
- dx: >30% of body surface area, nikolsky sign + (sloughing of superficial skin layers with gentle pressure), must have erythema and sloughing of mucosal surfaces including conjunctiva, oral, and vagina (2 or more)
- bx: full-thickness involvement of dermis
- tx: prednisolone
12
Q
bullous pemphigoid
A
- IgG Ab complexes deposit between the epidermis and dermis causing formation of fluid-filled bullae
-
autoimmune skin disorder with subepidermal blistering, mostly elderly onset 60-80, M=W, S. aureus
- Scenario: elderly who takes multiple meds
- sxs: large, tense bullae, but may begin as an urticarial eruption, fluid with clear fluid or hemorrhagic, discrete lesions arise on axilla, medial thigh, groin, abdomen, flexor arms, and lower legs, itchy, NOT PAINFUL, tense, not easy to rupture, lesions start as urticarial eruption, developing into bullae over wks to mos, no scar formation after but milia appear at sites of perv involved skin
- dx: nikolsky sign -: no sloughing of skin w/ light pressure
- skin bx: REQUIRED FOR DX - subep separation and intact ep
- tx: oral prednisone, alone or in combo with steroid-sparing Asathioprine, mycophenolate mofetil or tetracycline
13
Q
urticaria
A
- vascular rxn of skin marked by transient appearance of smooth, slightly elevated papules or plaques (wheals) that are erythematous and often itchy, IgE triggers release of histamine from mast cells
- etiology: drugs (NSAID, ASA, opiates, succinylcholine, abx), radiocontrast media\
- sxs: rapid onset pruritic erythematous wheals (lack of ep change, intense itching, presence of advancing edge and receding edge), life-threatening angioedema, features of anaphylaxis (HoTN, resp distress, stridor, GI distress, swallowing difficulty, jnt swelling, pain)
- dx: RAST
- tx: 2nd gen H1 antag: cetirizine, loratadine, fexofenadine (1st line), H2 antag (in combo with 2nd gen H1s - famotidine, ranitidine), 1st gen H1 antac (diphenhydramine, hydroxyzine, chlorpheniramine), epi for laryngeal angioedema
14
Q
actinic keratosis
A
- RF: sun exposure, considered premalignant (of SCC)
- sxs: 3-6mm in size, rough texture, red, scaly plaques, formation of yellow adherent crust
- dx: bx to exclude SCC
- tx: cryotx, curettage +/- electrocautery, shave excision, topical 5-FU or imiquimod, photodynamic tx
15
Q
seborrheic keratosis
A
- age 40+, benign, hereditary (autosomal dom), no association with sunlight
- sxs: usually multiple, located on all body surfaces except palms . and soles
- signs: well-circumscribed border, stuck-on or waxy (velvety) appearance, tan, brown, black color
- dx: dermoscopy - keratin pseudocyst, tend to get darker the longer theyve been present
- tx: cryotherapy, curette, electrocautery shave removal
16
Q
Lice
A
- Head: pediculus humanis capitis or pediculus capitis
- Genital: phthirus pubis
- Transmission: sexual contact, clothing, towels
- sxs: severe itching of scalp, body, groin
- signs: live lice and nits attached to hair on exam
- dx: requires observation of live lice, most commonly found behind ears and on back of neck
- tx: permethrin cream shampoo (elimite)
17
Q
scabies
A
- mites tunnel into skin, lay eggs, depositing feces (scybala), causing delayed type IV hypersens. rxn
- highly contagious via skin-skin contact, towels, bed linens, or clothes, caused by skin mite Sarcoptes scabiei var hominis
- sxs: burrows and typical distrib on . hands, feet, waist, axilla, or groin - linear marks, severe itching, especially at night
- signs: erythematous papules on wrists, between fingers, and in genital area, excoriation, characteristic burrows on hands, wrists, and ankles and in genital region
- dx: hx of itching, rash in typical distrib, hx of itching in close contacts, definitive dx = mites, eggs, fecal pellets, skin scraping from nonexcoriated burrows, papules, or vesicles
- tx: overnight tx with permethrin (no longer contagious after one tx although itching may continue), topical steroids and oral antihist for itching
18
Q
Rosacea
A
- common, chronic, progressive
- MC: white F
- avoid sun exposure, emotional stress, hot weather, wind, strenuous exercise, alc consump, hot baths, cold weather, spicy food, humidity, indoor heat, hot beverages
- sxs: central . facial erythema, symmetric flushing, stinging sensation, inflamm lesions, telangectasias, phymatous changes
- signs: erythematous edematous eruptions fof papulles and pustules on forehead, cheeks, nose, and eyes, NO COMEDONES
- tx: emollients, moisturizers, fragrance and soap-free cleansers, broad spectrum sunscreen with zinc, topical metronidazole FIRST LINE, topical + oral tetracycline, doxycycline, or minocycline for mod-severe disease
- erythematotelangiectatic = most difficult to treat: peristent erythema of central face, prolonged flushing, telangiectasias, burning/stinging, ocular may coexist
- papulopustular rosacea = easiest to tx: persistent central erythema with small papules and pinpoint pustules, burning/stinging, sparing of periocular and perioral areas, resembles acne vulgaris WITHOUT comedones
- phymatous: more common in men, marked skin thickening and irreg nodularities of nose, chin, ears, forehead, or eyelid, rhinophyma
- ocular: watery, bloodshot eyes, dry eye, foreign body . sensation, irritation, photophobia
19
Q
acne vulgaris
A
- four factors responsible: increased sebum production, hyperkeratinization of follicle, colinization by P. acnes, inflammatory rxn
- occurs on face, neck, chest, back, adding benzoyl peroxide to abx tx prevents risk of bact resistance
- after tx goals reached, oral abx should be replaced by topical retinoids for maintenance tx
- MC skin disorder in US, MCC = P. acnes, more prevalent in adolescents and more severe in males
- pathology: plugged follicles, retained sebum, bacterial overgrowth, release of fatty acids
- sxs: noninflamm → open comedones = blackheads, closed comedones = whiteheads
- inflammatory: erythematous papules, pustules, nodules or cysts
- dx: testosterone, FSH, LH, DHE-5 levels (not necessary for dx)
20
Q
acne tx mild, moderate, severe
A
- mild: noninflamm → topical retinoids, benxoyl peroxide, salicylic acid or azelaic acid; inflamm → topical tretinoin, topical benzoyl peroxide, topical abx (erythro or clinda)
- moderate: oral abx (tetracyclines, erythromycin, doxycycline, minocycline, bactrim, clindamycin) effective of monotx but better when combined w/ retinoids (topical benzoyl peroxide)
- severe: oral isotritinoin, must be member of iPLEDGE, premature closure of long bones, visual changes, elevated LFTs, laeukopenia, triglyceridemia, teratogenicity, oral abx topical retinoid benzoyl peroxide
21
Q
Spider bites
A
- Black widow: presynaptic release of most neurotrans (AcH, NE, Dop, glutamate)
- sxs: mod to severely painful bite, no surrounding inflamma, muscle spasms and rigidity starting at bite site w/in 30min-2h, spreads proximally to abd and face, rebound tenderness mimicking acute appy
- tx: resolves over 2-3d, death rarely occurs
- brown recluse: local cytotoxicity w/ subsequent ulcerating dermonecrosis, occurs early in morning, painless - delayed reaction (3-7d), arthralgias, fever, chills, maculopap rash, N/V, progress to ulcerating dermonecrosis at bite site, most ulcers heal over 1-8wk
- Tarantula: urticating hairs on dorsal abdomen, penetrate skin causing foreign body keratoconjuctivitis or ophthalmia nodosa, refer opthalmo if suspected eye injury (slit lamp exam)
27
Q
chronic paronychia
A
- inflamm of proximal paronychia more common in children
- RF: DM, systemic retinoids, protease inhibs
- sxs: hx continuous immersion of hands in H2O, contact w/ soap, detergents, other chemicals, similar to acute paronychia: erythema, tenderness, swelling of prox nail fold, retraction of prox nail fold, absence of adjacent cuticle
- signs: nail plate thickened and discolored with beau lines (inflamm of matrix) and nail loss, cross striations of nail, +/- pus
- dx: hx and PE, present at least 6 wks, strep, staph or candida on smear/cx
- tx: avoid exposure to irritants, topical antifungal and steroid (use emollients)
