The course of atopic dermatitis (AD) can vary from being a minimally distracting nuisance to calamitous. Often becoming apparent even in infancy, the course of AD is characterized by lifelong recurrences of pruritic dermatitis most commonly on the hands, face, scalp, and trunk. Unfortunately, there is no known cure for AD, although combinations of immune-modulating drugs — topical and systemic — can usually provide good symptomatic control.

It has not gone unnoticed that persons with AD are often hyper-responsive to a variety of topical irritants, including everyday contact items like wool clothing. Similarly, AD subjects have been shown to be more burdened with induction of contact dermatitis from the most commonly recognized contact allergens (e.g., metals such as nickel).

Following that line of thought, Shaughnessy et al sought to determine whether AD patients would also be more sensitive to commonplace preservatives found in topical creams, emollients, and moisturizers that are encountered in day-to-day living in such products as makeup, sunscreen, and hand lotions.

Using a panel of recognized skin-sensitizing preservatives, the investigators performed patch testing on patients suspected of allergic contact dermatitis (n = 2453). The panel of allergens included the seven most commonly recognized preservatives responsible for allergic contact dermatitis.

 AD patients were significantly more likely than non-AD patients to have positive patch tests. The category of topical agents known as formaldehyde releasers (e.g., quaternium-15, imidazolidinyl urea, diazolidinyl urea, DMDM hydantoin) was disproportionately represented among the sensitizing agents in AD subjects, and the authors suggest that AD patients be advised to avoid products containing these agents.