The authors of this article present an interesting, prospective, single-center, observational study of 105 patients. The allergenic capacity of Mercromina Film (Spanish tradename) was compared with other topical antiseptics used in clinical practice in dermatology clinics. Allergic contact eczema is of particular interest in dermatology patients, and suspicion of this condition is essential for appropriate study and diagnosis. Antiseptics do not form part of the standard Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) battery because of the irritant properties of these agents. They are therefore difficult to use in patch tests and, as a result, accurate diagnosis of allergic contact dermatitis is hindered. In terms of the results observed, povidone-iodine has a higher positivity rate compared with other antiseptics, probably because it is used more frequently, although we should remember that it can also cause irritation, and skin patch tests should be read with care. Merbromin has a lower positivity rate in the skin patch test compared with povidone-iodine, while no patient tested positive for chlorhexidine or eosin. Recently, it has been suggested in a prestigious dermatology journal that chlorhexidine should be used with precaution, or even not recommended, in head and scalp surgery.

The use of mercury-based antiseptics has fallen into disuse given the publication of multiple cases of sensitization to these products, including systemic conditions such as the so-called baboon syndrome. In the article, the authors suggest the use of merbromin as a topical antiseptic, and highlight the low rate of cross-reactions with 2 other mercury-based preparations, thiomersal and mercury metal.1 Although the decision of which antiseptic to use depends on the availability in the hospital, as well as the preferences of the dermatologists according to their experience, this interesting article opens the door to merbromin as an alternative antiseptic.