The triggering role of allergic contact dermatitis in discoid lupus erythematosus.

BACKGROUND: The onset and exacerbations of discoid lupus erythematosus (DLE) can be precipitated by several factors like needling, scratches, trauma, X-rays, heat, cold, pressure, tattooing, scars, allergic and irritant dermatitis and inflammatory dermatoses.

OBJECTIVE: To investigate the role of allergic contact dermatitis (ACD) in devolopment and triggering of the lesions of DLE.

MATERIALS AND METHODS: This study was performed on 30 patients with DLE. European baseline series and cosmetic patch test series were used. At least 1+ reaction was accepted as meaningful.

RESULTS: Twenty-three (76.7%) of 30 DLE patients and 16 (40%) of 40 control group patients were allergic to at least one allergen on standard patch test series. The difference between the groups were found statistically significant. Seventeen (56.7%) of 30 DLE patients and 6 (15%) of 40 control group patients were allergic to at least one allergen on cosmetic patch test series. The difference between the groups were statistically significant. The most sensitized allergens in both the groups were nickel sulphate, paraphenylen diamine, potassium dichromate from standard patch test series; quaternium 15, cocamidopropyl betain from cosmetic patch test series, in order.

CONCLUSION: This study is distinctive since it is the first study to determine the eliciting role of ACD on DLE by imposing standard and cosmetic patch test series on DLE and control group patients. Worldwide, there is no study based on this subject. In the DLE group, the results of sensitization on standard and cosmetic patch test series were higher and statistically significant. Larger studies are required to reveal the exact role.