Generalized skin hyperpigmentation and longitudinal melanonychia secondary to treatment with hydroxychloroquine in systemic lupus erythematosus.

We present the case of a 48-year-old-woman from Ecuador who was diagnosed with systemic lupus erythematosus in March 2004 based on symmetric polyarthritis which affected the wrists and small joints of the hands, as well as oral ulcers, Coombspositive hemolytic anemia, leukopenia and positive antinuclear, anti-DNA, anti-Sm, antiribonucleoprotein, anti-Ro/SSA and IgM and IgG anticardiolipin antibodies. In May 2004 she developed proteinuria and a renal biopsy was compatible with class IIIC lupus nephritis (focal sclerosing).1 Prednisone was started at 1 mg/kg/day in a descending pattern as well as azathioprine 100 mg/day, with good clinical response, but the latter was temporarily suspended in May 2009 due to herpes zoster and definitively in October 2010 due to persistent lymphopenia. At that time hydroxychloroquine was added at a dose of 200 mg/day, but the patient developed hyperpigmentation after 12 months on the drug. Physical examination showed a generalized bluish-gray pigmentation, which was more intense on the face and back of the hands (Fig. 1), as well as longitudinal bands of similar characteristics on the nails of the second finger of the left hand and the third finger on both hands (Fig. 2). No evidence of hyperpigmentation of the mucosal surfaces was seen. Laboratory analyses, including blood chemistry, hemogram, hormones (thyroid stimulating hormone, cortisol, ACTH) and acute phase reactants were within normal ranges. After reasonably ruling out other causes of generalized hyperpigmentation, including Addison’s2 disease, this event was attributed to treatment with hydroxychloroquine. However, we decided to continue the drug, in spite of the esthetic considerations, due to the high risk of SLE reactivation after its withdrawal,3 with the pigmentation remaining stable during follow up and without the development of ocular manifestations.