Megalopyge opercularis, a stinging caterpillar, has been a public health problem throughout the southern states. Survey of an "epidemic" in southern Texas showed a high percentage of severe symptoms, including constitutional reactions that required hospitalization in 3 cases. In fact, severity of reactions observed in some patients suggests the possibility that death could result from these stings, although no deaths were reported in the present survey. The symptoms most frequently observed were marked local pain, local swelling, lymphadenopathy, and headache; shock-like symptoms and convulsions were also noted. Hypersensitivity phenomena appear to be uncommon.
McGovern JP, Barkin GD, McElhenney TR, Wende R. Megalopyge OpercularisObservations of Its Life History, Natural History of Its Sting in Man, and Report of an Epidemic. JAMA. 1961;175(13):1155–1158. doi:10.1001/jama.1961.03040130039009