Finger 'pebbles'. A dermatologic sign of diabetes mellitus.

A 35-year-old obese man presented with a chief complaint of hand dryness of 5 years' duration. He was a store manager and denied exposure to chemicals, repetitive trauma, chronic irritation, and hard manual labor. However, he did admit to frequent hand washing. He had no itching or swelling in his hands, but on occasion he had tenderness in the dry areas. He had no personal or family history of diabetes, heart disease, or renal disease, and he stated that at his annual physical examination 6 months earlier, routine blood work was normal. He reported polyuria (every 2 hours), nocturia (five times per night), and polydipsia but no weakness, weight loss, visual changes, or neurosensory changes. Examination revealed xerosis of his hands and "pebbles" on the dorsal aspect of his fingers. The papules were most dense over the knuckles and interphalangeal joints (figures 1 through 3). He also had dozens of acrochordons (i.e., cutaneous papillomas, or skin tags) 1 to 4 mm in diameter on his neck, axilla, and groin. No other cutaneous lesions were noted. Specifically, there was no scleredema adultorum, necrobiosis lipoidica diabeticorum, acanthosis nigricans, bullae, or patchy pretibial pigmentation, although he did have several brown macules 1 to 5 mm in diameter on the sides of his lower legs. The macules had been present for years. Levels of hemoglobin A1c and glycated hemoglobin were 7.5% and 9.5%, respectively (normal, 4.4% to 5.9% and 5.0% to 7.3%). The patient was referred to his family physician, and his diabetes has been well controlled with insulin.