PSORIASIS


I. Pathophysiology and epidemiology

  1. Psoriasis is mediated by T-lymphocytes migrating to and causing inflammation in the epidermis and dermis.
  2. IL-12 and IL-23 are likely involved in stimulating T-cell activity in psoriasis
  3. Two peaks of onset, at ages 20-30 and 50-60yo
  4. Excess alcohol use is associated with risk as well as severity of psoriasis

II. May be associated with increased risk of:

  1. Myocardial Infarction--In a prospective population study; RR was 1.43 for severe psoriasis or 1.13 for mild psoriasis after controlling for known MI risk factors; no relation between meds for psoriasis and risk of MI (JAMA 296:1735, 2006--JW)
  2. Lymphoma, especially Hodgkin's lymphoma cutaneous T-cell lymphoma (HR 17.18 with severe psoriasis and 5.42 with mild psoriasis) (J. Invest. Dermatol. 126:2194, 2006--JW)
III. Treatment
  1. Coal tar preparations
  2. Topical corticosteroids
    1. Equally effective for chronic placque psoriasis as vitamin D analogues but with fewer local reactions per a 2010 Cochrane review
  3. "PUVA" (Psoralenz (topical or PO) + phototherapy (UVA))
    1. Psoralens can cause nausea, headache, and phototoxicity.
    2. It is thought that UVB may produce less photodamage and perhaps fewer skin cancers than PUVA.
    3. In a study in 88 pts with psoriasis randomized to PUVA vs. UVB 2x/wk (max 30 sessions), over 1y, the efficacy and durations of remission were sig. higher with PUVA (Arch. Dermatol. 142:836, 2006--JW)
    4. Does not reduce the excess cardiovascular risk associated with psoriasis
  4. Phototherapy (UVB)
  5. Calcipotriene, aka Calcipotriol (Dovonex) (see BMJ 320:963, 2000--AFP, JW)
    1. A topical synthetic vitamin D3 analogue
    2. More effective than placebo in adults but not children
    3. BID more effective than QD application
    4. More effective than coal tar or anthralin
    5. As effective as topical steroids in some trials
    6. May cause some skin irritation
    7. Can be used in combination with topical steroids
  6. Tazarotene (Tazorac)-A topical retinoid
  7. Methotrexate, cyclosporine, acitretin-For more severe disease; Methotrexate may reduce cardiovascular risk associated with psoriasis
  8. Anti-Tumor Necrosis Factor Medications
    1. Etanercept ass'd with sig. greater rates of clinical improvement c/w placebo in a randomized trial of about 600 pts with moderate-to-severe placque psoriasis (NEJM 349:2004, 2003--JW)
  9. Immunomodulators, Non-Steroid
    1. In a study in 167 pts with facial or intertriginous non-plaque-type psoriasis randomized to tacrolimus 0.1% pointment BID vs. placebo x 8wks, tacrolimus pts were sig. more likely to show improvement than placebo pts (67% vs. 37%) (J. Am. Acad. Dermatol. 51:723, 2004--AFP)
  10. Alefacept (Amevive)
    1. A T-cell-activation inhibitor
    2. Administered IM or IV
    3. Must monitor CD4+ T-lymphocyte counts during treatment
  11. Efalizumab (Raptiva)
    1. Monoclonal IgG Ab against the alpha-subunit of leukocyte-function-associated antigen type 1.  It binds to that subunit and inhibits T-cell binding to endothelial cells and T-cell activation
    2. Concern exists that agents that affet T-cell function may increase the risk of malignancies, infection, and autoimmune disease
    3. Associated with sig. greater rates of clinical improvement c/w placebo in two randomized trials of pts 18-75yo with moderate-to-severe placque psoriasis (NEJM 349:2014, 2003; JAMA 290:3073, 2003)
    4. Relapse occurs in many patients after cessation of treatment.
    5. Ass'd with headache, chills, fever, and myalgias more than placebo in randomized trials
    6. Removed from U.S. Market 2009 due to association with progressive multifocal leukoencephalopathy
  12. Ustekinumab (effective for both psoriasis and psoriatic arthritis)
  13. Oxsoralen (methoxsalen)
  14. Immunosuppressants
    1. 88 pts with moderate-to-severe psoriasis not responding to UVB randomized to methotrexate (5mg Q12h x 3) Qwk vs. cyclosporine (1.5mg/kg QD x 2) Qwk x 16wks; at 16wks, mean reduction in psoriasis severity score and incidence of complete remission were not sig. diff. between the two groups (NEJM 349:658, 2003--AFP)
IV. Psoriatic arthritis
  1. Occurs in 6-40% of pts with psoriasis, male:female 1:1
  2. Onset typically 7-10y after onset of cutaneous disease
  3. Assocaited with increased cardiovascular mortality compared to psoriasis without psoriatic arthritis
(Sources include Core Content Review of Family Medicine, 2012)