PRETREATMENT OF NICKEL TEST AREAS WITH SODIUM LAURYL SULFATE DETECTS NICKEL SENSITIVITY IN SUBJECTS REACTING NEGATIVELY TO ROUTINELY PERFORMED PATCH TESTS

A fair % of patients with a clinical history of nickel allergy show ne gative patch test results. To improve the response rate to NiSO4 5% pe t. patch tests, a testing procedure utilizing pre-treatment of the tes t area by a 24-h application of sodium lauryl sulfate (SLS) was introd uced. 46 women with a clinical history of nickel sensitivity, who exhi bited negative reactions to nickel sulfate 5% pet. patch tests, were s tudied. Patients underwent 6 patch tests on adjacent sites on the vola r surface of the forearms. 4 patch tests were performed with a 72-h ap plication of 40 mg nickel sulfate 5% pet. While 1 of these patch tests served as control, 3 test areas underwent 24-h pre-treatment with 40 mu l SLS, 1 with 0.1% and 2 with 0.5% solution. To evaluate difference s in the reactivity to SLS plus nickel sulfate related to the site on the forearm, 0.5% SLS pre-treatment was performed both on a proximal a nd on a distal test site. At the 72-h evaluation, 19 subjects out of 4 6 showed positive reactions to nickel sulfate 5% pet, at skin sites pr e-treated with 0.1% SLS, whereas 23 patients reacted positively at 0.5 % SLS pre-treated areas. Echographic values of skin thickness and of h ypo-echogenic dermal areas at positive pre-treated nickel test areas w ere higher than at control test areas, confirming the clinical evidenc e of an increased response to NiSO4 after SLS pre-treatment. The infla mmatory reaction, as evaluated clinically and echographically, was muc h higher at distal skin areas (0.1% SLS and distal 0.5% SLS) than at p roximal 0.5% SLS ones. (C) Munksgaard, 1996.