Post‐application occlusion substantially increases the irritant response of the skin to repeated short‐term sodium lauryl sulfate (SLS) exposure

Abstract

Occlusion often, but not always, enhances percutaneous absorption and thus may facilitate skin irritation. Quantitative data about the impact occlusivity may have on minimal irritant stimuli to which the skin is exposed in daily life, and which may lead to chronic irritant contact dermatitis, are however lacking. Irritant stimuli were administered by repeated application of sodium lauryl sulfate (SLS) in an open application procedure. After the open exposure, the skin was either left open or occluded with plastic. Skin irritancy was assessed by means of visual grading and by transepidermal water loss (TEWL) measurements. Post-exposure occlusive treatment markedly enhanced the irritant response. 5 consecutive daily applications produced more irritation, with or without occlusion, than alternate day application. Occlusion may be a relevant factor in the development of irritant contact dermatitis from certain chemicals.

Challenges and Opportunities in dermal/transdermal Delivery

“…Additionally, occlusion may increase the irritation potential of the topically administered API. For instance, Van der Valk and Maibach have shown that in ten healthy subjects the irritation response to repeated short-term exposure of sodium lauryl sulfate was enhanced with postexposure occlusion [95]. Functional damage to the skin barrier by occlusion, detected by transepidermal water loss, has also been reported [96].…”

Prediction of irritancy in the human skin irritancy model and occupational setting

“…Soap with a low pH (5·7) induced erythema and pruritus which did not occur at higher pH (9·5) (29). In another study, on the effects of occlusion, it was found that postexposure occlusion by a plastic wrap caused more severe irritation compared with unoccluded exposures to SLS (21). The degree of augmentation of the irritant response by occlusion differs between varying types of substances.…”

Occlusion vs. skin barrier function

“…In turn, these protective measures may produce negative events due to the nature of occlusion, which often causes stratum corneum hyper-hydration and reduces the protective barrier properties of the skin (12). Many gloves do not resist the penetration of low molecular weight chemicals: those chemicals may enter the glove and become trapped on the skin under occlusion for many hours, possibly leading to irritation, and more seriously, to dermatitis or eczematous changes (13)(14)(15). Wound dressings have been employed to speed the healing processes in acute and chronic wounds by keeping healing tissues moist and increasing superficial wound epithelialization (2,16,17).…”