Objective: To investigate an outbreak of gram-negative folliculitis in relation to a common exposure, mud wrestling, and identify risk factors for dermatitis among those who mud wrestled.
Design: Case-control study.
Setting: University of Washington, Seattle.
Participants: Two college-residence groups of students.
Results: Cultures from affected students and from mud similar to that used for wrestling yielded Enterobacteriaceae. The odds ratio associated with mud wrestling was 79.5 (95% confidence interval, 13.9 to 895.4). Increased time spent wrestling was associated with increased risk. Skin trauma during wrestling or immersion in the mud increased the risk of infection (odds ratio, 23.1; 95% confidence interval, 1.7 to 1440.4).
Conclusions: Mud wrestling is one cause of pustular follicular dermatitis. Trauma to the skin may be a necessary cofactor for the development of infection.