A teenage girl with knuckle hyperpigmentation

A girl in her late teens had experienced progressive fatigue and pigmentation over the dorsum of her hands for a month. She was a vegetarian, sexually inactive, had regular menstrual cycles, and did not use nutritional supplements. She did not have diabetes or symptoms of an autoimmune disorder. On examination she was pale and had slight conjunctival icterus and extensive hyperpigmentation over the knuckles of both hands (fig 1). Her body mass index was 17. Her spleen was palpable (1 cm) Oral mucosa, axillae, and neck areas had no pigmentation. Neurological examination was unremarkable. Her blood pressure was within normal limits for age, without any orthostatic changes. Table 1 shows the results of blood tests. Low ferritin levels suggested iron deficiency anaemia, which was treated with oral ferrous sulfate (200 mg three times a day). Owing to the increased vitamin …