VALUE OF EPICUTANEOUS PATCH TESTING IN PATIENTS WITH ORAL, MUCOSAL LESIONS OF LICHENOID CHARACTER

The purpose of the present investigation was to determine, in patients with oral mucosal lesions of lichenoid character, whether it is possi ble with epicutaneous patch tests, to detect those who will react favo rably to removal of amalgam. Of 48 patients, 19 (39.6%) showed positiv e patch test reactions to 1% mercury ammonium chloride, and 29 (60.4%) showed negative test results. The observation period varied from 3 mo nths to 3 yr (mean value 1.5 yr). After treatment, 94.7% of the positi ve group and 86.2% of the negative group showed regression of lesions. Reactions exceeding the contact zone between amalgam restorations and lesions showed positive patch test results in 21% of the cases, as co mpared with 47% among those with lesions restricted to the contact are as; 85.7 and 93.9%, respectively, showed regression after removal of a malgam restorations. The results of the present study indicate that re moval of amalgam usually affects the lesions favorably and that epicut aneous patch tests are of little prognostic value in patients with ora l mucosal lesions of lichenoid character.