To evaluate the association of
chronic infection with clinical features of
Behcet's disease (BD), we studied epidemiological and clinical features of 149 patients with only
aphthous ulcer and 294 patients with BD. The incidence of
chronic infection history was compared between both groups with age- and sex-matching and clinical manifestations of BD associated with high anti-
streptolysin O (ASO) titer were investigated. BD patients had more common history of
tonsillitis and
dental caries than
aphthous ulcer patients (P = 0.002 and P = 0.043, respectively). BD patients with persistently high anti-
streptolysin O titers had more frequent history of
tonsillitis (P = 0.001, odds ratio [OR] = 2.99, 95% confidence interval [CI] 1.53-5.82) and
erythema nodosum (EN)-like lesions (P = 0.001, OR = 3.02, 95% CI 1.54-5.93) and fewer history of genital
ulcer (P = 0.027, OR = 0.21, 95% CI 0.05-0.84) than BD patients with normal anti-
streptolysin O titer. Our results suggest persistently high ASO titers in BD patients could indicate that
streptococcal infections such as
tonsillitis are related to BD symptoms such as EN-like lesions. In these patients, ASO titer can be used in the evaluation of BD disease activity and
antibiotic treatments might be effective to control the symptoms of BD.