Pathergy reaction in Behcet's disease: Lack of correlation with mucocutaneous manifestations and systemic disease expression

Objective The pathergy reaction is a unique feature of Behcet's disease (BD) and, according to the International Study Group (ISG), is among the major criteria required for the diagnosis. Different positive pathergy reaction rates in ED have been reported worldwide. We evaluated the prevalence of the pathergy reaction in Israeli ED patients, and its relation to mucocutaneous and systemic manifestations of the disease. Methods Forty-three patients were studied, all of whom fulfilled the ISG criteria for ED. The mucocutaneous and systemic disease manifestations were analyzed with respect to the presence of the pathergy reaction, and a systemic severity score for ED was calculated according to the potential morbidity and mortality associated with various clinical features. Results Nineteen patients (44.2%) had a positive pathergy test. The pathergy-positive and pathergy-negative ED groups showed a similar male:female ratio, age at disease onset, and mean disease duration. They also exhibited similar HLA-B5 levels and a similar frequency of oral ulcerations in close family members. The mucocutaneous manifestations, systemic disease expression, and severity score were similar inpatients with and without the pathergy reaction. Conclusion The presence of a positive pathergy reaction, although common in Israeli ED patients, is not associated with an increased risk for specific mucocutaneous or systemic manifestations of the disease, and probably does not predict a more severe disease course.