Adding caffeine to topical skin treatments would be a simple way to reduce inflammation in patients with atopic dermatitis and psoriasis, suggests a review presented at the Psoriasis: From Gene to Clinic International Congress, which took place in London this week.

The researchers identified past studies which had investigated the effects of topical caffeine in atopic dermatitis or psoriasis, the results of which have all but been forgotten, and looked for potential mechanisms for caffeine’s positive effects.

Patients with atopic dermatitis and psoriasis have decreased intracellular cAMP levels in cutaneous leucocytes, and the reviewers propose that caffeine, being a methylxanthine and hence a phosphodiesterase inhibitor, raises intracellular cAMP levels, which suppresses inflammatory pathways.