Comparison of argon laser photocoagulation-induced cutaneous inflammation and skin pathergy test in Behçet's disease

Nonspecific increased inflammatory response is an important feature of Behçet's disease (BD). The skin pathergy reaction (SPR) which tests this hyperreactivity in the skin is frequently used as a diagnostic tool. This study aims to investigate the argon laser photocoagulation (ALP)-induced cutaneous inflammation in BD patients and controls and also to compare the results with the skin pathergy test (SPT). The study group consisted of 35 patients with BD and 28 healthy volunteers. The ALP was applied to the left forearms of all cases from 20-cm distance (2,000 mW, 100 microm) with exposure times ranging from 0.2 to 0.7 s with 0.1-s increments. Also, a SPT with three prics was performed to both forearms of all cases. The ALP-induced cutaneous inflammation and SPT were evaluated and scored with the same method at 48 h, and the SPR scores of 2+ and above was accepted as positive. Positive results as defined above were found in eight cases (23%) with the ALP and in nine (26%) with the SPT in patients with BD. There was no clear correlation between the ALP and SPT results and also between the exposure time to laser beam and SPR scores. The preliminary results of this study reveal that ALP can induce a skin hyperreactivity similar to the needle prick-induced SPR in patients with BD. We, herein, showed that ALP can induce skin inflammation with its thermal effect and without any inoculation of antigen in BD. This method would help to develop another experimental method to investigate the cutaneous inflammation in BD.