Methods and Method: In a prospective study, 72 confirmed cases of CMA in infants were examined for anal fissure by pediatricians with five years’ experience. A positive finding was defined as when an anal fissure was detected by at least two out of three examiners.

Results: Of infants with CMA with and without gastrointestinal GI symptoms, 79% and 83% had anal fissures, respectively. The prevalence of anal fissure in these infants is significantly higher than in normal infants.

Conclusion: Anal fissure may be a pathognomonic sign of cow’s milk allergy in infants.

Keywords: Anal fissure, Cow’s milk allergy, Diagnosis, Pathognomonic sign