In patients with extensive erythrasma diabetes occurs with sufficient frequency to warrant the routine performance of studies of carbohydrate metabolism. Nine of 19 patients with extensive erythrasma of the groins, axillae and/or trunk, proven by culture, and by coral-red fluorescence under a powerful Wood's light, were diabetics. Eight of the nine diabetics with erythrasma were obese. Six other patients had clinical evidence suggesting the presence of diabetes mellitus. These findings strongly suggest that diabetes mellitus may be a predisposing factor in the development of erythrasma.
Montes LF, Dobson H, Dodge BG, Knowles WR. Erythrasma and Diabetes Mellitus. Arch Dermatol. 1969;99(6):674-680. doi:10.1001/archderm.1969.01610240032005