An epidemiologic study of gypsy moth rash.

In 1981, outbreaks of itchy skin rashes were reported accompanying the heavy infestation of gypsy moths (GM) in the Northeastern United States. The rash problem was widespread and a considerable public annoyance. In the spring of 1982, during the period of greatest contact with the caterpillars, a telephone survey was carried out in a highly infested community (HI) and a minimally infested community (LO). Information was collected from 1,000 persons, representing more than 90 per cent of those selected for study. The one-week risk of rash was 10.4 per cent in the HI area and 1.6 per cent in the LO area, for a risk ratio (RR) of 6.5. The occurrence of rash was strongly related to a history of having had a rash in the previous year or having had a caterpillar crawl on the affected area. The combination of both factors additively increased the risk of rash. Hay fever and hanging the wash outside were other related variables. History of allergies other than hay fever since childhood and the use of insecticides were unrelated to rash occurrence.