Rx:

d/c lithium and -blockers

of scalp: steroids (DermaSmooth 0.01% hs, or other fluocinolone), Oluxfoam; salicylic acid solutions, tar shampoos, mineral oil

of other areas:

• Sunlight or other broad band UVB source, short of burn, which will cause flare
• Steroids topically (avoid systemic po steroids, which can precipitate pustular psoriasis) for small areas, with occlusive plastic dressings; or injections, eg, dilute (1:3) triamcinolone with lidocaine; adverse effects: widespread use leads to systemic absorption and adrenal suppression; can precipitate exfoliative erythroderm; skin atrophy; rebound much more likely than with anthralin
• Anthralin paste, 0.1%, 0.2%, or 0.4%, to rash qd for 10 min to 1 h, then removal with mineral oil, bath, and extensive hydrophilic ointment; or Z-tar emulsion (Dithranol) topically × 1 h, then shower, follow with UV; avoid groin; stains hair, skin
• Vit D analogs: Calcipotriene (Dovonex) (Med Let 1994;36:70) ointment 0.005% bid; a vit D analog, as good as topical steroids, although tachyphylaxis potential unknown; often used w potent or superpotent topical steroid initially then taper steroid; adverse effects: hypercalcemia at high doses because it is a vit D analog; now available only combined w betamethasone (Taclonex) much more expensive.
• Calcitriol (Vectical) ointment bid Tazarotene gel (Tazorac) (topical retinoid) (Med Let 1997;39:105) 0.05 or 0.1% qd to <20% of body surface (<40 gm/wk); for stable plaque type psoriasis; avoid in pregnancy; $2/gm

2nd-line meds, usually used w dermatologic collaboration:

• Methotrexate 2.5-5 mg q12h × 3 doses q1week, but check current guidelines (Arch IM 1990;150:889) w 1 mg folate po qd; 10% get liver disease (Am J Med 1991;90:711); equieffective as psoralen (Nejm 2003;349:658)
• Psoralen or methoxsalen po with UV-A (PUVA) highly effective, used tiw × 10 wk helps 85% then maintenance q1-4wk, but increases incidence of squamous cell cancer × 3 (Nejm 1984;310:1156) including male genitals unless protected (Nejm 1990;322:1093) and melanoma risk w 10-yr lag (Nejm 1997;336:1041)
• Immune suppression (Nejm 2001;345:248, 284):
• Monoclonal antibodies like interleukin 12/23 of CD4 and CD8 T cells, 90 mg sc q1wk × 4 helped 81% (Nejm 2007;356:580)
• TNF antagonists like infliximab, etanercept (Enbrel) (Nejm 2008;358:241) 50 mg biw, ustekinumab (Nejm 2010;362:118), adalimumab (Humira), alefacept (Amevive) (Med Let 2003;45:31) 7.5-15 mg iv/im q1wk × 12; adv effects: chills w infusion, cost $8400/12 wk
• Cyclosporine works, though nephrotoxic (J Am Acad Derm 1995;32:78; Nejm 1991;324:1277)
• Acitretin (Soriatane) (Med Let 1997;39:106) 25-50 mg po qd w food; adv effects: teratogenic for 3 yr after stop, elevated LFTs can revert on rx, various anterior eye changes, all worse w alcohol, pseudotumor cerebri esp w tetracycline; $7/pillof arthritis: (Ankylosing Spondylitis) (Arch Rheum 1996;132:215)