# Skin Barrier Biomarkers in Patch‐Induced and Clinical Allergic and Irritant Contact Dermatitis

## TL;DR

This study examines skin barrier changes in irritant and allergic contact dermatitis using specific biomarkers, finding consistent impairments in both patch-induced and clinical cases.

## Contribution

The study identifies specific stratum corneum biomarker changes in patch-induced and clinical allergic and irritant dermatitis, revealing no differences between clinical ICD and ACD.

## Key findings

- CholGlc was significantly elevated in both patch-induced ICD and ACD.
- Chromium-induced ACD showed the strongest biomarker response compared to nickel and MI.
- NMF and IL-1α levels decreased in ICD and chromium-induced ACD.

## Abstract

Skin barrier impairment is central to irritant (ICD) and allergic contact dermatitis (ACD). Stratum corneum (SC) components cholesterol sulphate (CholSulph), glucosylcholesterol (CholGlc) and natural moisturising factor (NMF) are critical for barrier function, but their changes in ICD and ACD remain underexplored.

To measure CholSulph, CholGlc, NMF and IL‐1α in patch‐induced ICD and ACD and in hand dermatitis (HD) diagnosed as ICD or ACD.

SC samples were collected from HD patients undergoing patch testing. Biomarkers were analysed in positive reactions to sodium lauryl sulphate (ICD, n = 44), allergens (ACD, n = 113; nickel, chromium, methylisothiazolinone [MI]), lesional HD skin (n = 45) and control (empty chamber, n = 121).

CholGlc was significantly elevated in patch‐induced ICD and ACD. CholSulph was increased in ICD and chromium‐ and MI‐induced ACD. NMF decreased in ICD, while IL‐1α decreased in ICD and chromium ACD. Chromium induced the strongest response, nickel the weakest. In HD, ICD and ACD showed elevated CholGlc, reduced NMF and IL‐1α, with CholSulph increased only in ACD. No biomarker differences were detected between clinical ICD and ACD.

Both induced and clinical ICD and ACD show consistent SC biomarker changes reflecting barrier dysfunction, with no differences between clinical ICD and ACD.

Both patch‐induced and clinical ICD and ACD showed consistent alterations in skin barrier‐associated biomarkers, indicative of skin barrier impairment. Among the tested allergens, chromium elicited more pronounced biomarker responses compared to nickel and methylisothiazolinone.