Glucose Monitoring Dermopathy.

A 75-year-old man had been monitoring his glucose using a blood glucose monitoring system at the same body site for at least 20 years (>7300 needlesticks). The asymptomatic skin lesion had been present for many years. He used the same site because it hurt less than the fingers and bled well. His medical history was remarkable for diabetes mellitus, hypertension, coronary artery disease, and a pacemaker. His medications included glipizide, metformin, carvedilol, furosemide, lisinopril, amlodipine, clopidogrel, and aspirin. Physical examination revealed a brown, slightly raised, rough plaque with focal, punctate hemorrhagic crusts, on the distal area of the right thigh (Figure 1). The clinical differential diagnosis was more likely to be lichen simplex chronicus than pigmented Bowen's disease. A skin biopsy demonstrated an acanthotic epidermis with coarse collagen bundles in a thickened papillary dermis with extravasated erythrocytes, consistent with a dermal reparative reaction (Figure 2).