Occupational dermatitis associated with straw itch mites (Pyemotes ventricosus)

T. G. Betz, B. L. Davis, P. V. Fournier, J. A. Rawlings, L. B. Elliot and D. A. Baggett

A 1981 outbreak of dermatitis in Austin, Tex, was traced to occupational exposure to wheat infested with the straw itch mite, Pyemotes ventricosus; the wheat was being sold for decorative purposes by an imported-goods store located on the second floor of a large, modern, shopping mall complex. In addition to an extensive varicelliform skin eruption, one employee also had chills, fever, malaise, diarrhea, and anorexia associated with her exposure to these mites. The straw itch mite has been associated with several large epidemics of dermatitis during the 19th and 20th centuries. This outbreak is the third reported in Texas since 1961. Physicians should consider the possibility of straw itch mite infestations of products brought into the home or places of employment when they observe patients with a varicelliform or chigger-bite-like dermatitis, which may be accompanied by constitutional symptoms.