Objective. To evaluate the potential role of environmental agents in t
he etiopathogenesis of Behcet's disease. Methods. Twenty-eight Behcet'
s disease patients and 56 controls were recruited prospectively from t
he outpatient rheumatic disease clinic at the Escola Paulista de Medic
ina between July 1991 and July 1992. Behcet's disease was diagnosed us
ing one of the accepted sets of criteria (Japanese Committee, Internat
ional Committee, O'Duffy, Mason and Barnes, James). The control patien
ts, who had other rheumatic diseases, were matched on age and sex with
the Behcet's disease patients. To investigate environmental factors,
a standardized questionnaire was administered to each subject during a
n interview. Clinical and laboratory investigations were performed in
each subject according to a predefined protocol. Results. Analysis usi
ng the chi-square test or Fisher's exact test (Cochran's restriction)
disclosed significant associations between Behcet's disease and a hist
ory of herpes simplex virus type 1 infection or streptococcal infectio
n. Conclusions. Despite the small sample size, our data strongly suppo
rt a role of infectious agents in the etiopathogenesis of Behcet's dis
ease. Further studies in larger patient populations are needed to conf
irm our results.