Clinical insights about the role of pH in atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is a common chronic inflammatory skin disease with a prevalence of up to 25% of children and ranging from 2.1% to 4.9% of adults world-wide. AD has tripled since the 1950s, now affecting 3.5% of adults in Canada and the US. The dramatic increase in prevalence has occurred mainly in countries that follow a western lifestyle, and may be due to factors enhancing skin surface pH.

AD presents with relapsing and remitting cycles; many AD sufferers describe being worried about the next disease exacerbation. In fact, adult patients with AD report feeling helpless (31%), anxious (40%), and irritable (31%) “quite a lot” when they think about a new disease exacerbation. Moreover, patients with moderate AD report having 113 days of disease exacerbation per year, while those with severe AD note having disease exacerbation more than half of the year (192 days).

The pathogenesis of AD is multifactorial and includes genetic and environmental factors. AD presents clinically as erythematous and pruritic patches of skin with varying severity. Inflammation is believed to occur when the skin barrier becomes dysfunctional and an immune response is stimulated. Vice versa, the inflammatory response itself may impair the skin barrier function; once the barrier is disrupted, feedback loops are initiated. Maintaining a physiologically low skin surface pH may help to keep the skin barrier intact, reducing the risk for AD development and exacerbation of flares.

C. Lynde, J.Tan, S. Skotnicki, et al