Background and aim: Psoriasis is one of the most common papulosquamous diseases that often requires long-term maintenance therapy. Long-term use of topical corticosteroids on the face and intertriginous areas will increase the risk of steroids side effects such as striae and atrophy development. A safe, effective and inexpensive modality in topical therapy of inverse psoriasis is required. adrenergic antagonists has been reported to exacerbate existing plaque psoriasis because of increasing concentration of intracellular cAMP. On the other hand, caffeine is a methylxanthin that inhibits phosphodiesterase enzyme and results in a higher concentration of intracellular cAMP. We evaluated the efficacy of topical caffeine 10% in the treatment of psoriasis.
Materials and Methods: This randomized, double blind, controlled clinical trial was performed on 39 patients with typical lesions of psoriasis vulgaris who referred to dermatology clinics of Isfahan University of Medical Sciences from December 2002 to July 2003. These patients were randomized in two groups and treated by topical application of drug or placebo, three times per day. The patients were seen in two-week intervals for 8 weeks, and their PASI score was assessed in each visit.
Results: The decrease of PASI score after 2,4,6 and 8 weeks compared to the first visit in caffeine treated group were 23%, 41%, 54%, and 62% and in placebo treated group were 15%, 19%, 25%, and 29% respectively(P<0.05).
Conclusion: Topical caffeine may be an effective, safe and inexpensive therapy in psoriasis but its onset of action is late.