Reflectance confocal microscopy features of irritant cutaneous reactions to sodium lauryl sulphate in healthy adults / 中华皮肤科杂志

ABSTRACT

Objective To investigate reflectance confocal microscopy (RCM) features of irritant cutaneous reactions to sodium lauryl sulphate (SLS) in healthy persons aged from 18 to 60 years,to analyze effects of age and gender on cutaneous reactions,and to estimate the value of RCM in objective evaluation of cutaneous reactions.Methods An occlusive patch test was performed on the back of 120 healthy testees with 0.1％ and 0.5％ SLS solution (0.1％ and 0.5％ SLS groups) and distilled water (negative control group) for 48 hours.At different time points after the patch removal,clinical evaluation and RCM were performed.Results RCM imaging in the 0.1％ and 0.5％ SLS groups showed parakeratosis,indistinct structure of the stratum corneum,spongiosis and infiltration of inflammatory cells in the epidermis,and telangiectasia in the papillary dermis.The incidence of RCM features reached the peak until 24 hours after the removal of 0.1％ and 0.5％ SLS patches,and the incidence of telangiectasia in the dermis was up to 66.7％ and 95.0％ in the 0.1％ and 0.5％ SLS groups respectively.At 24 hours after the removal of 0.5％ SLS patch,the incidence of spongiosis was significantly lower in the males than in the females (68.9％ [42/61] vs.84.7％ [50/59],x2 =4.24,P ＜ 0.05).However,the incidence of spongiosis was significantly higher in testees aged 18-40 years than in those aged 41-60 years at 24 hours after the removal of 0.1％ SLS patch (53.3％[32/60] vs.35.0％[21/60],x2 =4.09,P ＜ 0.05).For the other RCM features,there were no significant differences in their incidence between different genders or age groups after the removal of 0.1％ and 0.5％ SLS patches (all P ＞ 0.05).Clinical evaluation showed that after the removal of 0.1％ and 0.5％ SLS patches,no significant difference in the incidence of irritant cutaneous reactions was observed between the males and the females or between the testees aged 18-40 years and those aged 41-60 years (all P ＞ 0.05).There were good correlations between the clinical evaluation results and RCM features.At 24 hours after the removal of 0.1％ SLS patch,the correlation coefficient between spongiosis and clinical evaluation results was up to 0.77,so was that between telangiectasia in the dermis and clinical evaluation results (both P ＜ 0.001).However,at 0.5 hour after the removal of SLS patches,clinical evaluation showed that the positive reaction rates were 2.5％ (3/120) and 12.5％ (15/120) in the 0.1％ and 0.5％ SLS groups respectively.In the meantime,there were 17.5 ％ (21 / 120) and 51.7％ (62/120) of testees manifesting more than 2 RCM features in the 0.1％ and 0.5％ SLS groups respectively,which were more similar to the clinical evaluation results at 24 hours after the removal of SLS patches (34.2％ [41/120] and 85.0％ [102/120] in the 0.1％ and 0.5％ SLS groups respectively) compared with the clinical evaluation results at 0.5 hour after the removal of SLS patches.Conclusions Neither gender nor age affects irritant cutaneous reactions to 0.1％ and 0.5％ SLS.Compared with clinical evaluation,RCM can evaluate cutaneous reactions more objectively and accurately in the early stage of irritant reactions.