Pre-treatment 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 negative patch test results. To improve the response rate to NiSO4 5% pet. patch tests, a testing procedure utilizing pre-treatment of the test area by a 24-h application of sodium lauryl sulfate (SLS) was introduced. 46 women with a clinical history of nickel sensitivity, who exhibited negative reactions to nickel sulfate 5% pet. patch tests, were studied. Patients underwent 6 patch tests on adjacent sites on the volar surface of the forearms. 4 patch tests were performed with a 72-h application 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 microliters SLS, 1 with 0.1% and 2 with 0.5% solution. To evaluate differences 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 and on a distal test site. At the 72-h evaluation, 19 subjects out of 46 showed positive reactions to nickel sulfate 5% pet. at skin sites pre-treated with 0.1% SLS, whereas 23 patients reacted positively at 0.5% SLS pre-treated areas. Echographic values of skin thickness and of hypo-echogenic dermal areas at positive pre-treated nickel test areas were higher than at control test areas, confirming the clinical evidence of an increased response to NiSO4 after SLS pre-treatment. The inflammatory reaction, as evaluated clinically and echographically, was much higher at distal skin areas (0.1% SLS and distal 0.5% SLS) than at proximal 0.5% SLS ones.
Seidenari
S
S
Department of Dermatology, University of Modena, Italy.
Motolese
A
A
Belletti
B
B
D000328:Adult; D000704:Analysis of Variance; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D009532:Nickel / Q000009:adverse effects*; D010328:Patch Tests / Q000379:methods*; D012680:Sensitivity and Specificity; D012967:Sodium Dodecyl Sulfate / Q000008:administration & dosage; D013501:Surface-Active Agents / Q000008:administration & dosage
D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; D009532:Nickel