In the 1950s, Harry Hurley and Walter Shelley, distinguished dermatologists at the University of Pennsylvania, devoted considerable attention to the apocrine gland. Their curiosity extended beyond human subjects, and their most fascinating subject was a rotund inhabitant of the Philadelphia Zoo, Jimmy the Hippopotamus.
Since ancient times, travelers to the Nile Valley in Africa had reported that hippopotamuses “sweat blood.” Hurley and Shelley noted that Jimmy, when annoyed, excreted a “bloody” red sweat, especially on his head and shoulders. Since he was not fond of his handlers, their mere appearance elicited this response. The dermatologists were not foolhardy enough to attempt a biopsy on Jimmy and were not allowed to administer drugs to stimulate or diminish sweating. However, the slimy, turbid nature of the red discharge, as well as its association with emotional stimuli, convinced them it was apocrine in nature.1 In his autobiography many years later, Shelley wrote, “Just contemplating any experiments on Jimmy gave our axillae a nice wash of apocrine and eccrine sweat.”2
Burgdorf WHC, Hoenig LJ. Solving the Mystery of Jimmy’s Red Sweat. JAMA Dermatol. 2014;150(8):884. doi:10.1001/jamadermatol.2013.10605