Psoriasis Flashcards
Psoriasis.
Classification
- plaque psoriasis 2. guttate psoriasis 3. erythrodermic psoriasis
- pustular psoriasis 5. inverse psoriasis
Psoriasis
Pathophysiology
- not fully understood, genetic and immunologic factors
* shortened keratinocyte cell cycle leads to th1- and Th17-mediated inflammatory response
Psoriasis
Epidemiology
1.5-2%, M=F
• all ages: peaks of onset: 20-30 yr old and 50-60 yr old
• polygenic inheritance: 8% with 1 aected parent, 41% with both parents aected
Psoriasis
Differential Diagnosis
AD, mycosis fungoides (cutaneous T-cell lymphoma), seborrheic dermatitis, tinea, nummular
dermatitis, lichen planus
Psoriasis
Investigations
• biopsy (if atypical presentation, rarely needed)
psoriasis
• risk factors:
smoking, obesity, alcohol, drugs, infections, physical trauma (Koebner phenomenon)
PLAQUE PSORIASIS
Clinical Feature. Worsing. Auspitz sign. common site
• chronic and recurrent disease characterized by well-circumscribed erythematous papules/plaques with
silvery-white scales
• often worse in winter (lack of sun)
• Auspitz sign: bleeds from minute points when scale is removed
• common sites: scalp, extensor surfaces of elbows and knees, trunk (especially buttocks), nails, pressure
areas
PLAQUE PSORIASIS
Management depends on
severity of disease, as defined by BSA afected or less commonly PASI
• mild (<3% BSA).
- moderate (3-10% BSA) to severe (>10% BSA)
PLAQUE PSORIASIS
Management.
mild (<3% BSA)
topical steroids, topical vitamin D3 analogues, or a combination of the two are first line
topical retinoid ± topical steroid combination, anthralin, and tar are also effective but tend to be less
tolerated than first line therapies
emollients
phototherapy or systemic treatment may be necessary if the lesions are scattered or if it involves sites
that are dicult to treat such as palms, soles, scalp, genitals
PLAQUE PSORIASIS
Management.
moderate (3-10% BSA) to severe (>10% BSA). Goal
goal of treatment is to attain symptom control that is adequate from patient’s perspective
phototherapy if accessible
systemic or biological therapy based on patient’s treatment history and comorbidities
topical steroid ± topical vitamin D3 analogue as adjunct therapy
Topical Treatment of Psoriasis. Mechanism
Emollients
Reduce fissure formation
Topical Treatment of Psoriasis. Mechanism.
Salicylic acid 1-12%
Remove scales
Topical Treatment of Psoriasis. Mechanism of Tar (LCD: liquor carbonis detergens)
Inhibits DNA synthesis, increases cell
turnover. Poor long-term compliance
Topical Treatment of Psoriasis. Mechanism of Topical Corticosteroids
Reduce scaling, redness and thickness.
Use appropriate potency steroid in
different areas for degree of psoriasis
Topical Treatment of Psoriasis. Mechanism of Vitamin D3 analogues: Calcipotriene /
calcipotriol (Dovonex®, Silkis®)
Reduces keratinocyte hyperproliferation