Psoriasis Flashcards
epi of psoriasis
2% of world
bimodal pattern (childhood, adulthood)
northern european descent
mild, moderate, severe based on % of body affected
psoriatic plaque morphology
well-demarcated circular, oval, or polycyclic erythematous plauqes that are symmetric in distribution
very thick (micaceous) and silvery scales
distribution of psoriasis
scalp, elbows and knees
lesions can last from months to years in the same location
what is auspitz sign?
removal of scale result in pinpoint bleeding, suggesting dianosis
scraping will raise bright white or silvery scales
what is this a presentation of?
Koebner phenomena
trauma-induced psoriasis
can interpret as slow healing wounds
what dermatitis co-exist with psoriasis
seborrheic dermatitis
psoriatic nail changes can be seen in absence of cutaneous involvement
T
what changes are seen in psoriatic nail disease
nail pitting
onycholysis (lifting of distal nail plate)
splinter hemorrhages
subungual hyperkeratosis
leukonychia
oil drop changes (red-brown discoloration)
what is inverse pattern of psoriasis
intertriginous areas of body
(axillae, groin, genitals, submammary area)
erythematous and well-demarcated but lack classic scale
how is scalp psoriasis treated
topical descaling agents such as salicylic acid or corticosteroids
what is this a presentation of?
pustular psoriasis
widespread erythematous, sterile pustules
palmar and plantar involvement
increased risk for psoriasis patients
CV disease (MI, PE, cerbrovascular accidents)
screen for diabetes, cholesterol, hypertension, obesity, smoking
chronic renal disease
Tx for psoriasis
IV light therapy
<10% BSA involvement: topical (retinoid, corticosteroid, vit D analog, topical tar, anthralin)
>10% BSA: systemic (methotrexate, mycophenolate mofetil, cyclosporine, tacrolimus, acitretin)
what is this a presentation of?
pityriasis rosea
describe pityriasis
discrete oval, erythematous, scaly plauqes and patches oriented along skin cleavage lines
most commonly on trunk and upper extremities
face palms, soles are usually spared
what is this a presentation of?
herald patch
solitary, scaly, pink or flesh-colored plaque
speculated etiology of pityriasis rosea
associated with systemic reactivation of human herpes virus 6 and 7
what pattern does pityriasis rosea present in?
begin with herald patch (truncal), with fine collarette of scale, patches and plaques form along skin fold lines on trunk
what is this a presentation of?
lichen planus
describe the pathophysiology of lichen planus
autoreactive T lymphocytes attack basal kertinocytes in skin, mucous membranes, hair follicles, and/or nail units
unclear etiology
presentation of lichen planus
pruritic, flat-topped, pink to purple papules that are localized most commonly along the volar wrists, shins, presacral area, and hands
what has been associated with cause of lichen planus?
hep b vaccination
medications causing lichen planus-like eruption
what phenomenon is a hallmark of lichen planus (same for psoriasis)
Koebner phenomenin
what is this a presentation of?
lichen planus
describe mucous membrane involvement of lichen planus
lacy, net-like, white plaques with violaceous base on tongue or buccal mucosa
Tx of lichen planus
withdraw potential offending medication
antihistamines for pruritus
systemic corticosteroids
metronidazole
systemic retinoids
phototherapy
what is this a presentation of?
pityriasis rubra pilaris (PRP)
acute cutaneous eription accompanied by pruritus and/or pain
follicular papules on erythematous base coalescing to form large orange-red plauqes but islands of sparing
commonly begin on scalp, rapidly spread in craniocaudal direction
what is this a presentation of?
erythroderma
diffuse redness of skin >90% of body surface
causes of erythroderma
psoriasis, atopic dermatitis, idiopathic erythroderma, cutaneous T-cell lymphoma, drugs
what can induce erythroderma?
drugs such as allopurinol, ampicillin, omeprazole, vancomycin
