A 38-year-old woman was referred to our department with a 12-year history of a hypertrophic plaque on the right upper arm and multiple scaly erythema on the face. She had been treated with topical 0.1% tacrolimus and clobetasone propionate for several years without improvement. At the initial visit, multiple atrophic erythema and scars were observed on the right cheek and nose. Small erosions and atrophic scars were noted on the lips. A single scaly hypertrophic plaque surrounded by erythema was revealed on the right upper arm (Fig. 1a). The kidney, heart, joints and central nervous system were unaffected. Laboratory examinations found antinuclear antibody to be positive (1:160, homogenous and cytoplasmic pattern). Anti-Sm, anti-ssDNA, anti-dsDNA and anti-SS-B antibodies were within the normal ranges, and anti-SS-A antibody was slightly elevated. Complete blood count and complement levels were normal. Histopathological examination of a biopsy from the hypertrophic plaque on the right upper arm showed marked hyperkeratosis, irregular acanthosis and liquefaction degeneration. There were focal mononuclear cell infiltrates around the skin appendages of the dermis, accompanied by dermal mucin deposition (Fig. 1b,c). We made the diagnosis of chronic cutaneous lupus erythematosus (LE) with discoid and hypertrophic LE lesions on the face and the right upper arm, respectively. After confirming by fundoscopy that the patient had no retinopathy, the patient was administrated 200 mg/day (4.65 mg/kg per day) of oral hydroxychloroquine (HCQ). Within 2 months of the HCQ administration, multiple scaly erythema on the cheek disappeared, leaving pigmentation and scars, and the hypertrophic plaque on the right upper arm started to flatten. After 6 months of HCQ treatment, the hypertrophic plaque was obviously flattened, and the surrounding erythema had disappeared, leaving pigmentation (Fig. 1d). The Cutaneous Lupus Erythematosus Disease Area and Severity Index score decreased from 11 to 6 in activity and from 4 to 3 in damage.Hypertrophic LE is a rare variant of chronic cutaneous LE that is characterized by irregular epidermal hyperplasia and hyperkeratosis.1 Treatments are local cryotherapy, topical corticosteroids and intralesional triamcinolone acetonide. The skin lesions are, however, often chronic and refractory to these therapies. HCQ is an antimalarial drug that has been used as a standard treatment for LE, especially for severe and widespread cutaneous LE and refractory cutaneous LE. 2,3 In Japan, however, HCQ was not approved until recently, because of the side-effects of a similar drug (chloroquine), most notably retinopathy. It is well known that severe retinopathy from HCQ can be avoided by using the appropriate dose in conjunction with regular retinal examinations. The high-magnification image shows liquefaction degeneration of the epidermal basal membrane zone and mononuclear cell infiltration (HE, 9200). (d) Clinical manifestations after 10 months of treatment with HCQ. The hypertrophic lesion has markedly flattene...