Evaluation of the efficacy of topical caffeine in the treatment of psoriasis vulgaris.
BACKGROUND
Psoriasis is a common disease which often requires long-term maintenance therapy. In psoriatic epidermis, the level of cyclic adenosine monophosphate (cAMP) decreases. It has been reported that beta-blockers exacerbate existing psoriatic plaque and decrease the concentration of intracellular cAMP. Caffeine is a methylxanthine that inhibits phosphodiesterase enzyme and results in a higher concentration of intracellular cAMP.


OBJECTIVE
Evaluation of the efficacy of topical caffeine 10% in the treatment of psoriasis.


METHODS
The patients were treated by topical application of 10% caffeine or placebo three times per day on the right or left side of the body (randomly selected by flipping a coin). Thirty-nine patients with stable plaque psoriasis were included in a randomized, double-blind, placebo-controlled, right/left comparison. The patients visited every other week for a period of 8 weeks. Their Psoriatic Area and Severity Index (PASI) scores were assessed at each visit.


RESULTS
The reductions in PASI scores measured at the four visits for the caffeine-treated group were 2.64+/-2.89, 4.47+/-3.62, 5.73+/-4.16, 6.58+/-4.40 and for the placebo-treated group the values were 1.45+/-2.32, 3.04+/-2.68, 4.02+/-3.36, 4.43+/-3.45, respectively. Comparing the corresponding results of the two groups, p values at the second, fourth, sixth and eighth week were 0.081, 0.083, 0.079 and 0.047, respectively. Based on presented p values, the treatment with caffeine is more effective than with placebo after 8 weeks (p<0.05), and the only side effect of caffeine is mild itching.


CONCLUSIONS
Based on the results of the trial, topical caffeine is an effective, safe and inexpensive treatment for psoriasis, with a delay in action.
Vali
Anahita
A
Department of Dermatology, Isfahan University of Medical Sciences (IUMS), Iran. vali@med.mui.ac.ir
Asilian
Ali
A
Khalesi
Elaheh
E
Khoddami
Leila
L
Shahtalebi
Mohammadali
M
Mohammady
Maryam
M
D000287:Administration, Topical; D000328:Adult; D002110:Caffeine / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D011565:Psoriasis / Q000188:drug therapy* / Q000473:pathology; D016896:Treatment Outcome
D010726:Phosphodiesterase Inhibitors; D002110:Caffeine