Effect of allergens and irritants on levels of natural moisturizing factor and corneocyte morphology.

Sjors A Koppes,Rainer Voegeli,Monique H.W Frings‐Dresen,Nika Franceschi,Ružica Jurakić Tončic,Ivone Jakasa,Sanja Kezic,Thomas Rustemeyer,Majella E Lane,Christoph Riethmüller,Anthony V Rawlings,Nidhin Raj,Branka Marinovic,Suzana Ljubojević Hadžavdić,Marek Haftek

doi:10.1111/cod.12770

Abstract

SummaryBackgroundThe irritant sodium lauryl sulfate (SLS) is known to cause a decrease in the stratum corneum level of natural moisturizing factor (NMF), which in itself is associated with changes in corneocyte surface topography.ObjectiveTo explore this phenomenon in allergic contact dermatitis.MethodsPatch testing was performed on patients with previously positive patch test reactions to potassium dichromate (Cr), nickel sulfate (Ni), methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI), or p‐phenylenediamine. Moreover, a control (pet.) patch and an irritant (SLS) patch were applied. After 3 days, the stratum corneum from tested sites was collected, and NMF levels and corneocyte morphology, expressed as the amount of circular nanosize objects, quantified according to the Dermal Texture Index (DTI), were determined.ResultsAmong allergens, only MCI/MI reduced NMF levels significantly, as did SLS. Furthermore, only MCI/MI caused remarkable changes at the microscopic level; the corneocytes were hexagonal‐shaped with pronounced cell borders and a smoother surface. The DTI was increased after SLS exposure but not after allergen exposure.Conclusions MCI/MI significantly decreased NMF levels, similarly to SLS. The altered corneocyte morphology suggests that skin barrier damage plays a role in the pathogenesis of MCI/MI contact allergy. The DTI seems to differentiate reactions to SLS from those to the allergens tested, as SLS was the only agent that caused a DTI increase.

Highlights

The irritant sodium lauryl sulfate (SLS) is known to cause a decrease in the stratum corneum level of natural moisturizing factor (NMF), which in itself is associated with changes in corneocyte surface topography
SLS may lead to an increase in the stratum corneum pH, which might affect the activity of stratum corneum proteases, including those involved in filaggrin degradation into NMF components
The results suggest that it is unlikely that the decrease in NMF levels after SLS and MCI/MI treatment is caused by reduced activity of these enzymes, as their activities showed an opposite trend; protease activities were increased after SLS treatment, and an increasing trend was observed for MCI/MI (p = 0.07)

Summary

Introduction

The irritant sodium lauryl sulfate (SLS) is known to cause a decrease in the stratum corneum level of natural moisturizing factor (NMF), which in itself is associated with changes in corneocyte surface topography. After 3 days, the stratum corneum from tested sites was collected, and NMF levels and corneocyte morphology, expressed as the amount of circular nanosize objects, quantified according to the Dermal Texture Index (DTI), were determined. Only MCI/MI reduced NMF levels significantly, as did SLS. Only MCI/MI caused remarkable changes at the microscopic level; the corneocytes were hexagonal-shaped with pronounced cell borders and a smoother surface. MCI/MI significantly decreased NMF levels, to SLS. The DTI seems to differentiate reactions to SLS from those to the allergens tested, as SLS was the only agent that caused a DTI increase

Methods

Results

Discussion

Conclusion