Derm dz

atopic dermatitis (eczema) - etiology

personal or family hx of atopy (AD, asthma, allergic rhinitis)

childhood onset most common

genetic, environmental, immunological factors

atopic dermatitis (eczema) - s/s

pruritic, xerotic (dry), exudative, lichenified eruption

ill-defined, scaly, red plaques, loss of pigmentation

darker skin - follicular accentuation, post-inflammatory hyperpigmentation

atopic dermatitis (eczema) - dx

clinical presentation - need 3 major criteria = itchy, eczematous, relapse, personal or family hx

atopic dermatitis (eczema) - tx

emollients or bleach bathing

high potency topical corticosteroids for a short period of time depending on severity

irritant contact dermatitis - etiology

80% of contact dermatitis cases

localized to area of direct contact

develops within 24 hours of contact with irritant

irritant contact dermatitis - s/s

erythematous rash with well defined borders localized to area of direct contact

burning sensation

chronic - scaling, erythema, and thickened skin

irritants - acids, plastics, detergents, food, water, plants, bodily fluids

allergic contact dermatitis - etiology

20% of contact dermatitis cases

extends beyond area of contact with allergen

delayed response - may take 24 to 72 hours to develop

type IV hypersensitivity - requires prior sensitization

common occupations - textile workers, cashiers, shoemakers, hairdressers, medical , masseuse

allergic contact dermatitis - s/s

pruritic, erythematous rash with ill-defined borders extending past area of direct contact

itchy

contact dermatitis - dx

clinical presentation

localized vs. widespread

burning vs. itching

contact dermatitis - tx

avoidance of irritants

topical corticosteroids

antihistamines

severe - prednisone

dishidrotic eczema (pompholyx) - etiology

not an independent disease - linked with AD, ICD, ACD

hyperhidrosis (excessive sweating)

stress

dishidrotic eczema (pompholyx) - s/s

extremely pruritic “tapioca” vesicles on lateral and medial aspects of fingers, palms, and soles

dishidrotic eczema (pompholyx) - dx

clinical presentation

don’t need skin biopsy or KOH unless trying to rule out other pathologies

dishidrotic eczema (pompholyx) - tx

high potency topical corticosteroids

stasis dermatitis - etiology

venous hypertension due to incompetent valves

chronic venous insufficiency

stasis dermatitis - s/s

occurs in lower extremities around the ankle area

pruritus, discoloration, hyperpigmentation, edema, scaly dry skin

stasis dermatitis - dx

venous doppler

clinical presentation

stasis dermatitis - tx

compression stockings

vein ablations

wet to damp gauze dressings

lichen planus - etiology

idiopathic

systemic drugs and HepC

lichen planus - s/s

very itchy!

5 P’s - pruritic, purple, polygonal, papules, and plaques with fine white streaks (Wickham striae)

flexor surfaces, mucous membranes

lichen planus - dx

clinical presentation - cardinal findings = typical skin lesions, mucosal lesions, and histopathological features of band-like infiltration of lymphocytes in upper dermis

lichen planus - tx

super potent topical corticosteroids

candidiasis - etiology

Candida albicans

common normal flora but opportunistic pathogen

common in diabetic patients, pregnancy, obese, immunocompromised

can be secondary to abx, oral corticosteroids, oral contraceptives, or hormone therapy

candidiasis - s/s

beefy redness and itching primarily in bold fold areas or moist areas

burning around the affected vulva or anus

candidiasis - dx

clinical presentation - moist, erythematous plaques usually in body fold areas

KOH positive for cluster of buddying yeast and pseudohyphae

candidiasis - tx

keep area dry

mild = antifungal topical or ointment

vaginal - fluconazole

drug eruptions - etiology

delayed T-cell mediated hypersensitivity

• morbilliform (most common)

• fixed

immediate-type hypersensitivity

• urticarial

morbilliform drug eruption - s/s

maculopapular

erythematous macules that sometimes become slightly palpable and confluent

symmetrical distribution beginning on trunk and spreading to extremities

fixed drug eruption - s/s

solitary dusky erythematous plaque that may be edematous or bullous

urticarial drug eruption - s/s

wheals that usually resolve within 24 hours

drug eruptions - dx

clinical presentation with precise medication hx prior to rash onset

drug eruptions - tx

discontinue suspected medication triggers

topical corticosteroids

photosensitivity disorders - etiology

UV radiation

phototoxic (most common)

• medication becomes activated by UV exposure causing damage to skin that looks like rash or sunburn

• happens within minutes - timing is important

photoallergic

• UV rays interact with ingredients of meds applied direct to skin

• body recognizes changes caused by UV exposure as foreign threat

• production of antibodies and attacks = rxn

• takes a couple days, not immediate

photosensitivity disorders - s/s

painful or prurutic erythema, edema, or vesciulation on sun-exposed surfaces

peeling of epidermis and pigmentary changes

photosensitivity disorders - dx

clinical presentation - localization of rash to sun exposed areas

photosensitivity disorders - tx

sunscreen

severe = systemic corticosteroids

pityriasis rosea - etiology

idiopathic

healthy adolescents and young adults

pityriasis rosea - s/s

initial herald patch - skin-to-pink-to-salmon colored patch or plaque with slightly raised advancing margin

single herald patch will progress to christmas tree pattern on posterior trunk

darker skin - lesions are more papular and hyperpigmented

pityriasis rosea - dx

clinical presentation

histopathology to nonspecifically rule out tinea vs. psoriasis

definitive = KOH or skin biopsy

pityriasis rosea - tx

no treatment required

low to medium topical corticosteroids

psoriasis - etiology

immune-mediated disease

usually leads to psoriatic arthritis in 5-30% of patients

genetic and environmental triggers

psoriasis - s/s

symmetric distribution of sharply defined plaques covered with silvery scales

mild to moderate = usually asymptomatic

severe or widespread = severe pruritus

present on elbows, knees, scalp, and lower back and legs

if symptomatic to nail and scalp, more likely to develop into psoriatic arthritis

psoriasis - dx

clinical presentation

definitive = biopsy

psoriasis - tx

based on BSA involvement and presence of secondary diseases like arthritis

vitamin D3 - inhibit epidermal proliferation

topical corticosteroids or retinoids

erythema multiforme (EM) - etiology

does not usually progress to SJS/TEN

rarely caused by drugs

HSV = most common cause

erythema multiforme (EM) - s/s

acute, self limited

symmetrical, fixed, erythematous papules

true targetoid appearance

minor - extensor surfaces, face, mild to no mucosal, no systemic sx

major - all minor locations, but severe mucosal and systemic sx

erythema multiforme (EM) - dx

clinical presentation - good H&P

skin biopsy

erythema multiforme (EM) - tx

oral variant - oral and topical corticosteroids

widespread and severe lesions - systemic prednisone

oral prophylaxis for HSV

SJS/TEN - etiology

always drug related

usually abx, antiepileptic, neurological meds

1-3 weeks after initiating drug therapy

SJS/TEN - s/s

SJS - <10% BSA detachment

SJS/TEN 10-30% BSA

TEN - >30% BSA detachment

initial sx - fever, stinging eyes, pain upon swallowing

progresses to erythema and erosions of buccal, ocular, and genital mucosae and increased epidermal involvement

full-thickness necrosis, dusky red macular lesions

detaching of epidermis

SJS/TEN - tx

discontinue all meds

burn care/ICU

bullous pemphigoid - etiology

primarily affects the elderly

drugs such as furosemide

autoimmune

bullous pemphigoid - s/s

subepidermal blistering in flexural areas

starts as pruritic urticarial and edematous lesions that progress to blistering

symmetrical distribution

does not happen in the mouth!!

bullous pemphigoid - dx

biopsy with direct immunofluorescence exam and serum antibody testing

punch biopsy = closer to lesion, DIE = further away from lesion

bullous pemphigoid - tx

mild/localized disease - superpotent topical corticosteroid

extensive/persistent - superpotent TCS and oral corticosteroid

pemphigus vulgaris - etiology

autoimmune

happens in the mouth!!

pemphigus vulgaris - s/s

relapsing crops of bullae that are fragile leading to rupturing and erosions

lesions usually appear first on oral mucous membrane, skin, or on erythematous base

Nikolsky sign - intact epidermis shears away from underlying dermis leaving a moist surface

Asboe-Hansen sign - bulla-spread phenomenon = pressure on intact bulla gently forces fluid to spread to adjacent skin

GI involvement

pemphigus vulgaris - dx

Light microscopy, direct (skin) and indirect (serum and blood) immunofluorescence (IIF) microscopy, and ELISA to detect autoantibodies to desmoglien 3 and 1

pemphigus vulgaris - tx

severe = hospitalized at bed rest with IV abx

mild = topical corticosteroids, systemic or local abx

rosacea - etiology

idiopathic

possible factors

• immune factors

• vascular hyperreactivity or neurogenic inflammation

• demodex folliculorum

• genetics

• UV exposure

rosacea - s/s

gradual onset of facial redness, flushing, or “pimples” on central face

no comodones are seen

• erythematotelangiectatic (vascular) - flushing and persistent central facial erythema with or without telangiectasia

• papulopustular (inflammatory) - persistent central facial erythema with transient papules and/or pustules

• phymatous - thickening skin, irregular surface nodularities and enlargement (nose, chin, forehead, cheeks or ears)

• ocular - FB sensation in eye, burning or stinging, dryness, itching, ocular photosensitivity, telangiectasia of sclera, periorbital edema

rosacea - dx

clinical presentation

biopsy only for severe cases

rosacea - tx

avoid triggers (EtOH, spicy foods)

topical abx or benzyl peroxide

oral abx if topical doesn’t work

do not give topical steroids!!

acne vulgaris - etiology

Cutibacterium acnes or Propionibacterium acnes

inc sebum production, cohesion, and hyperproliferation of keratinocytes —> inflammation —> rupture

acne vulgaris - s/s

• comedomal

  • closed - white head

  • open - black head

• papulopustular - papules, pustules, small cysts

• nodular - severe cystic acne

acne vulgaris - dx

clinical presentation - comedones

acne vulgaris - tx

mild comodonal - topical retinoid

mild papular/pustular - topical retinoid and topical abx

mod papular/pustular - oral abx, topical retinoid, BPO

severe - isotretinoin

seborrheic dermatitis - etiology

Malassezia species - lipid dependent fungi

occur in areas rich in oil glands (head, neck, chest, back)

seborrheic dermatitis - s/s

sharply demarcated patches or thin plaques that may be flaky but not itchy

pink-yellow to dull red to red brown in color

crusting may occur

areas rich in sebacous glands

usually associated with HIV, mood disorders and neuroleptic drugs, Parkinson’s, stroke, DM, obesity

seborrheic dermatitis - dx

clinical presentation - distribution and involvement

skin biopsy may be needed with exfoliative erythroderma

fungal culture to r/o tinea

seborrheic dermatitis - tx

topical azoles

low potency topical corticosteroids and emollients

tinea - etiology

Trichophyton rubrum - most common dermatophyte worldwide

tinea corporis - s/s

rings of erythema that have an advancing scaly border and central clearing

pruritus and burning

tinea corporis - dx

KOH - hyphae

tinea corporis - tx

topical antifungals

never give topical corticosteroids —> tinea incognitio

tinea pedis - etiology

most common dermatophyte infection

acquired going barefoot (locker rooms, gyms, public facilities)

moccasin, interdigital, inflammatory (vesicular), ulcerative

tinea pedis - s/s

scaling, peeling, itchiness, redness

moccasin - soles of feet

interdigital - interdigital web spaces

tinea pedis - tx

topical antifungals

refractory - oral antifungals for diabetics, immunocompromised, and moccasin type

tinea versicolor - etiology

Malassezia furfur

tropical climates with high humidity

sebum-rich areas

tinea versicolor - s/s

multiple oval to round patches or thin plaques with mild scale

upper trunk and shoulders favored

common colors - brown (hyperpigmented), tan (hypopigmented)

sometimes mild inflammation with pink color

usually asymptomatic, only appearance

tinea versicolor - dx

KOH - pseudohyphae

ziti and meatballs

tinea versicolor - tx

ketoconazole

selenium sulfide shampoo

paronychia - etiology

chronic immersion of hands in water or trauma to the nail fold

acute = Staphylococcus aureus

chronic = Candida albicans

paronychia - s/s

erythema, swelling, and pain of nail fold along with retraction of cuticle

acute - painful and purulent

chronic - without fluctuance

paronychia - dx

clinical presentation showing soft tissue infection of lateral or proximal nail folds

paronychia - tx

I&D of abscess and topical abx

black widow bite - etiology

Lactrodectus mactans - release of neurotoxin Ach

found in the outdoors, usually in wood piles or shoes

black widow bite - s/s

muscular pain

muscle spasms

muscle rigidity

black widow bite - tx

Lactrodectus antivenom

parenteral opioids or muscle relaxants

brown recluse spider bite - etiology

Loxosceles reclusa - release cytotoxin

inside tiny dark spots or in bed sheets or clothing

brown recluse spider bite - s/s

local progressive necrosis of tissue

brown recluse spider bite - dx

enzyme immunoassay to detect venom in skin biopsy

brown recluse spider bite - tx

excision of necrotic tissue

oral corticosteroids

anecdotes (dapsone, colchicine)

verrucae - etiology

direct person to person contact

common warts by HPVs

verrucae - s/s

<1cm hyperkeratotic, exophytic and dome-shaped papules or nodules

usually asymptomatic unless on plantar (painful with pressure) or anogenital (itchy)

usuallyfound on fingrs, dorsum of hand, palmar and plantar

verrucae - dx

clinical presentation

definitive = punch biopsy

verrucae - tx

cryotherapy with liquid nitrogen

OTC salicylic acid

Herpes (Varicella) Zoster - etiology

primary varicella (chicken pox)

reactivation of latent varicella infection (Shingles)

Herpes (Varicella) Zoster - s/s

shingles - painful grouped vesicles on an erythematous base within a single unilateral dermatome

chicken pox - dew drops on rose petal = vesicle on erythematous base; very pruritic

Herpes (Varicella) Zoster - dx

clinical presentation of dermatomal rash or dew drops on rose petal