Case report of recalcitrant allergic contact eczema successfully treated with teriflunomide

Abstract

Allergic contact dermatitis (ACD) is a type IV, delayed‐type reaction caused by skin contact with low‐molecular‐weight organic chemicals and metal ions that activate antigen‐specific T cells, primarily T‐helper 1 (Th1), in a sensitized individual, leading to skin eczema.First‐line treatments are based on avoidance of causal agents and topical corticosteroids/immunomodulators. In recalcitrant cases, chronic oral immunosuppressive agents may be used, but they may have serious adverse effects and do not address the immunological disfunction. We report a case of severe ACD, unresponsive to topical or oral immunosuppressive therapy, which resolved itself after treatment with teriflunomide (TF) 14 mg/daily used for multiple sclerosis. TF is a once‐daily, oral selective and reversible dihydroorotate dehydrogenase inhibitor, revealing a new treatment option for ACD.