G157
Psoriasis
Several reports show that the safest treatment for psoriasis may be a combination of a vitamin D ointment (1) and oral antibiotics (2). Psoriasis means that you make too much skin because your immunity is overactive. We do not know if an infection is the trigger of the overactive immunity. New skin cell is laid down at its innermost part. Then another cell is laid down underneath that. As each successive new cell is laid down underneath it, the cell over it moves outward, until it is shed as dander or dandruff 28 days later. Psoriasis means that the skin turns over 7 times as fast as normal so cells are shed after only four days, instead of the usual 28. This causes thick plaques to form on top of the skin, particularly at the elbows and knees and the face and scalp develop thick scales, and the nails thicken and grow very fast. So, all treatments for psoriasis are aimed at slowing skin turnover rate to normal.
The most common treatment includes cortisone-type ointments, but continued use can cause irreversible thinning. Doctors prescribe light treatments and drugs that sensitize the skin to sunlight (3), but they can cause skin cancer, even the deadly melanoma (4), many years later. Surprisingly, inexpensive commercial tanning parlors may be as effective in treating psoriasis as the highly expensive PUVA treatment administered by dermatologists (5). For severe psoriasis, doctors use poisons, such as methotrexate, but sulfasalazine is far safer, even though it is not as effective (6).
Psoriatic arthritis is very difficult to treat. I often prescribe sulfasalazine 1000 mg T.I.D. plus cephalexin 500 mg twice a day plus Cordran tape on the lesions. For severe cases, the treatment of choice is probably cyclosporine 250 mg per day, but it is loaded with potential side effects (7). Vitamin D ointment slows skin turnover and is not a poison. It is applied to the thick psoriatic plaques at bedtime and covered with special plastic wrap. Rapid spread of psoriasis is usually caused by infection, so doctors often prescribe antibiotics, such as cephalosporins, to kill staph and strep two germs that commonly cause psoriasis to worsen. There is no effective treatment for nails deformed by psoriasis. The most effective is 5% 5-fluorouracil cream applied nightly for several months.
A study from the University of Michigan showed that Rezulin, a drug that was used to treat diabetes, might help to control psoriasis (9). Rezulin has been taken off the market, but two similar drugs, 30 mg/day of Actos or 4 mg per day of Avandia, should act the same way. Psoriasis is caused by a defect that forces the skin to turn over seven times as fast as normal skin, and PPAR-gamma is a chemical that regulates how fast cells make new cells. Rezulin treated diabetes by making cells more sensitive to PPAR-gamma so they needed less insulin. PPAR-gamma also slows the rate that cells form new calls. 400 mg of Rezulin cleared men with total body psoriasis. If this study can be repeated, doctors should have an effective treatment for psoriasis, that is safer than other pills used to treat this disease. I have treated patients with total body psoriasis with Avandia and an injection of triamcinolone. Thick plaques that covered the entire body weree gone in two months , and the nails cleared up also.
1) SI Cullen, L Drake, T Kahn, HI Katz, RW Loss, MT Jarratt, T Funicella, C Whitmore, H Luber, A Ison, EL Jones, S Primmer, C Huerter, D Kingsley, H Moss, S Bruce, J Milbauer, I Kantor, J Lederman, J Shavin. Long-term effectiveness and safety of topical calcipotriene for psoriasis. Southern Medical Journal 89: 11(NOV 1996):1053-1056. calcipotriene 0.005% ointment is safe and effective.
2) SL Gottlieb, et al. Response of psoriasis to a lymphocyte-selective toxin (DAB389IL-2) suggests a primary immune, but not keratinocyte, pathogenic basis. Nature Medicine 1995;2:442-447.
3) Z Evenpaz, R Gumon, V Kipnis, DJ Abels, D Efron. Dead Sea sun versus Dead Sea water in the treatment of psoriasis. Journal of Dermatological Treatment 7: 2 (JUN 1996):83-86.
4) NEJM, April 10, 1997.
5) AB Fleischer, AR Clark, SR Rapp, DM Reboussin, SR Feldman. Commercial tanning bed treatment is an effective psoriasis treatment: Results from an uncontrolled clinical trial. Journal of Investigative Dermatology 109: 2 (AUG 1997):170-174.
6) B Combe, P Goupille, JL Kuntz, J Tebib, F Liote, C Bregeon. Sulfasalazine in psoriatic arthritis: A randomized, multicentre, placebo-controlled study. British Journal of Rheumatology 35: 7 (JUL 1996):664-668. SSZ, at a dose of 2.0 g/day appeared to be a safe treatment in patients with psoriatic arthritis. At this dosage, its efficacy was only demonstrated for the pain variable.
7) Charles Ellis and John Koo in symposium at the annual meeting of the American academy of DErmatology Feb 27 to March 4, 1998.
8) Cutis July, 1998 volume 62.
9) Archives of Dermatology, May, 2000. Page 609.
Checked 3/9/08