To the Editor: Psoriasis is a well-known cutaneous adverse effect of lithium treatment
(1). Among the various options for treatment are infusions with omega-3 fatty acids (2, 3). Recently, we participated in a double-blind, placebo-controlled study on the effects of the addition of a maximum of 6 g/day of omega-3 fatty acids containing eicosapentaenoic acid (EPA) ethyl esters to patients with bipolar disorder. In this study, two patients reported a spontaneous reduction of psoriasis, possibly related to taking omega-3 fatty acids.

Our positive findings regarding 4–6 g/day (but not 2 g/day) of omega-3 fatty acids in these two patients with lithium-associated psoriasis are in line with the positive results from recent studies of infusions of omega-3 fatty acids in patients with acute psoriasis (3). In addition to studies in patients with bipolar disorder, we suggest further studies of omega-3 fatty acids in patients with (lithium-associated) psoriasis.