Lithium Therapy Associated with Hidradenitis Suppurativa: Case Report and Review of Dermatologic Side Effects

In the 1995 case report, a 42-year-old woman developed hidradenitis suppurativa (HS) after starting lithium therapy for bipolar disorder, marking a rare association not widely reported in English literature. Upon discontinuing lithium and switching to divalproex sodium, her HS improved but did not fully resolve. The review highlighted other dermatologic side effects of lithium, including psoriasis, acneiform lesions, folliculitis, alopecia, and maculopapular/macular eruptions, with an incidence rate of 3% to 34%. These side effects often show a reduced response to conventional treatments. Women may be more susceptible to these effects. The exact mechanism of lithium's impact on skin is unclear, but it may involve changes in second messenger systems or inhibition of adenylate cyclase. Acneiform lesions or folliculitis may not respond well to treatment, and reducing or discontinuing lithium can be helpful. Alopecia, a common side effect, typically appears within the first six months of therapy and may improve after stopping lithium. The document also notes that severe side effects like exfoliative dermatitis have been reported.