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 BD have been reported worldwide. We evaluated the prevalence of the pathergy reaction in Israeli BD 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 BD. The mucocutaneous and systemic disease manifestations were analyzed with respect to the presence of the pathergy reaction, and a systemic severity score for BD 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 BD 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 in patients with and without the pathergy reaction. Conclusion: The presence of a positive pathergy reaction, although common in Israeli BD 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.