Patch Testing in Patients with Lichen Simplex Chronicus / 대한피부과학회지

ABSTRACT

BACKGROUND: Lichen simplex chronicus (LSC) may develop under various chronic pruritic conditions, such as allergic contact dermatitis (ACD). However, there have been only a few studies on the relationship between ACD and the development of LSC. OBJECTIVE: To investigate the clinical features and frequency of contact sensitization in patients with LSC. METHOD: In a retrospective study, 71 patients with LSC, who had shown resistance to conventional treatment and had been examined with patch tests in the Korean standard series, were evaluated for their clinical features and results of the patch testing. RESULTS: 1. The patients comprised of 32 males and 39 females. The mean age was 51.8 (19-80) years, and the highest incidence was shown in the 50-60 year age range. The predominant sites of the dermatitis were the trunk (25.4%), arms (16.7%), widespread on the body (14.7%), the scalp (9.8%) and the neck (9.8%). 2. Sixty five (91.5%) out of 71 patients showed a positive reaction to one or more allergens. The highest sensitization rates were found with nickel sulfate (38%), balsam of Peru (25.6%), 4-phenylenediamine base (23.9%), fragrance mix (22.5%), mercury ammonium chloride (18.3%), cobalt chloride (18.3%) and potassium dichromate (15.5%). CONCLUSION: This study shows that contact sensitization may possibly play an etiologic role in the development of LSC, and there are some dominant allergens, including nickel, 4-phenylenediamine, balsam of Peru and fragrance mix. Therefore, when LSC is resistant to conventional treatment, it is important to carry out patch testing, and to bear in mind the possibility of ACD contributing to the development of LSC.