[Topical antimicrobial agents in dermatology]

Topical antimicrobial agents are chemical substances that, directly applied to the skin, inhibit the growth or destroy any microorganism, either fungi, viruses or bacteria. Within this term, we generally refer to those that are active against the latter. They are divided into antiseptics and antibiotics. Antiseptics are directly applied to a living organism to eradicate the existing microorganism on the mucocutaneous surfaces, preventing their proliferation. Topical antibiotics are either produced by living organisms or manufactured through synthesis and are mainly used to fight infections. Topical antimicrobials represent an important option in the prophylaxis and treatment of primary and secondary superficial bacterial infections. Antibiotics for topical use have a lower incidence of systemic toxicity, secondary effects and development of resistance than parenteral antibiotics. The ideal topical antimicrobial must have a broad spectrum of activity, fast and prolonged antibacterial effect, bactericidal activity, easy diffusion through tissues and detritus, with minimal toxicity, very low or null incidence of irritation or allergy and sparse activity against normal skin flora. The approach of this article is the description of the classical and new antimicrobials that are, more important due to their wide use and proven efficacy. We review their pharmacological characteristics, spectrum of activity, possible secondary effects and interactions, as well as the combinations that improve their antimicrobial activity, main indications and possible development of resistance, all this properly documented.