We had great interest in reading the published paper fromBoulous and colleagues, who demonstrated mycophenolate mofetil (MMF) contributes to the treatment of diffuse scleroderma. 1 Dr Tang and Dr Joo respectively mentioned that MMF is effective for induction of membranous glomerulonephritis and lupus nephritis. 2,3 MMF and mycophenolic acid (MPA) have been widely prescribed for rheumatic diseases, including lupus nephritis, cutaneous diseases and for preventing rejection after organ transplantation. Gastrointestinal symptoms and bone marrow suppression are the most commonly noticed adverse effects. 4 Nonetheless, nail disorder is rarely reported to be an adverse effect of MPA. Here, we reported the first case of MPA-induced onychomadesis. A 34-year-old woman presented at our clinic with unhealed cutaneous ulcers that had persisted for 6 months bilaterally on her lower legs. The patient did not have medical problems but used to smoke two packs of cigarettes per day. Physical examinations showed normal bilateral palpable dorsalis pedis pulsation. Contrast computed tomography revealed a bilateral occlusion of her posterior tibialis arteries with collateral circulation in the lower limbs. Laboratory evaluations showed normal white cell count, erythrocyte sedimentation rate, and C-reactive protein level, and did not show the presence of autoantibodies. Culture of the unhealed wound revealed no microorganism growth. Histological examination of her unhealed wounds indicated mixed acute and chronic inflammation with granulation tissue formation, and focal neutrophilic infiltration of the vascular wall. Thromboangiitis obliterans (TAO) was diagnosed. She received a silver-containing foam dressing, daily medications with colchicine 0.5 mg, and MPA 360 mg. Onychomadesis developed bilaterally in all 20 proximal nails of phalanges 1 month after MPA (Figure 1A).Nail lesions went into remission gradually 1 month after withdrawing MPA ( Figure 1B), and total remission three month after, whereas she was still taking colchicine ( Figure 1C).Thromboangiitis obliterans, a nonatherosclerotic segmental occlusive vasculitis, is often noted in young adults and diagnosed based on unhealed cutaneous ulcers on distal lower limbs, tobacco use, and exclusion of autoimmune diseases. 5 The histological findings of TAO reveal that T lymphocytes outnumber B lymphocyte infiltration in the thrombi and intima. 6 Thus, MPA was prescribed for these refractory cutaneous ulcers in this TAO woman.