We read with interest the recent article by Batalla et al.1 on the use of hand hygiene and antisepsis products among health care professionals and the relationship between these products and hand eczema. While we are in full agreement with the central message of the article and the authors’ algorithm for the management of patients with intolerance to alcohol-based products, we would like to add the following points.

Since 2009, when the World Health Organization published its guidelines on hand hygiene for health care professionals,2 there has been a marked upswing in the distribution and use of alcohol-based products because of the numerous advantages they offer over traditional handwashing.

The hand rubs that have achieved the greatest commercial success (e.g., Sterillium and Manorapid r.f.u.) are those that contain isopropyl alcohol (Chemical Abstract Service number 67-63-0).

Before these products were developed, isopropyl alcohol was rarely used in medical or cosmetic preparations. Type IV hypersensitivity reactions were, therefore, rare3 leading some authors to even doubt whether isopropyl alcohol was in fact an allergen in humans.4

However, the marked increase in the use of products containing isopropyl alcohol has led to a substantial increase in exposure. At the same time, it has been found that isopropyl alcohol is potentially an important allergen, especially when used directly on the skin although also in the case of occupational exposure.5

In Europe, there are already numerous reports of health professionals who have been diagnosed with contact allergy to this substance, especially nurses and nursing assistants working in highly specialized units where frequent hand sanitizing is required (An Goossens, personal communication). In fact, in our own department we have diagnosed 2 young nurses with allergic contact dermatitis to isopropyl alcohol.

It is important to remember that, in addition to isopropyl alcohol, commercial alcohol-based hand rubs may contain other ingredients, such as emulsifiers, additives (lanolin, propylene glycol, bisabolol), and perfumes, and that the allergenic potential of these components may be even greater than that of the alcohol.6,7

For all these reasons—and as Batalla et al.1 clearly indicate in their algorithm—the role of allergic contact dermatitis should not be overlooked when patients who habitually use alcohol-based sanitizers present with hand eczema. Consequently, patch testing is recommended in the case of persistent and clearly associated lesions. A practical alternative diagnostic technique available to any specialist is a repeated open application test with the actual product used by the patient.8 It is very possible that the cause is allergic if the patient develops lesions after twice-daily application (morning and evening) on an area of approximately 5cm2 on the anterior forearm, for at least 2 weeks.

Finally, we would like to thank the authors of this excellent review on a very current issue of great relevance to dermatologists, who must be aware of the issues involved and up to date on the methods for diagnosing and treating these patients.