[Dermatitis Caused by Hair Dye (Quinone Produced by the Action of Aqueous Hydrogen Peroxide on p-Phenylenediamine Hydrochloride), by Juan de Azúa].

In the first issue of Actas Dermo-Sifiliográficas, Juan de Azúa published a magnificent article on contact dermatitis caused by hair dyes, which reflects his profound knowledge of allergy and how the skin responds to chemical stimuli. It gives a brilliant description of irritative and allergic dermatitis, although without naming the allergic form explicitly. Of note is how he is concerned about the composition of <<those Parisian dyes>>; so much so that he contacted the local laboratory to determine their chemical composition and how they work. It is a delight to study the case histories and treatments administered to these 15 patients. During the months of treatment, he reports trying different officinal formulas that, although unknown to most of today's dermatologists, nevertheless managed to cure the patients in the end.