Recent advances in the field of nanotechnology have allowed the manufacturing of elaborated nanometer-sized particles for various biomedical applications. A broad spectrum of particles, extending from various lipid nanostructures such as liposomes and solid lipid nanoparticles, to metal, nanocrystalline and polymer particles have already been tested as drug delivery systems in different animal models with remarkable results, promising an extensive commercialization in the coming years. Controlled drug release to skin and skin appendages, targeting of hair follicle-specific cell populations, transcutaneous vaccination and transdermal gene therapy are only a few of these new applications. Carrier systems of the new generation take advantage of improved skin penetration properties, depot effect with sustained drug release and of surface functionalization (e.g., the binding to specific ligands) allowing specific cellular and subcellular targeting. Drug delivery to skin by means of microparticles and nanocarriers could revolutionize the treatment of several skin disorders. However, the toxicological and environmental safety of micro- and nanoparticles has to be evaluated using specific toxicological studies prior to a wider implementation of the new technology. This review aims to give an overview of the most investigated applications of transcutaneously applied particle-based formulations in the fields of cosmetics and dermatology.

These results suggest that particles based on PLA polymers may be ideal carriers for hair follicle and sebaceous gland targeting.

Pityriasis rosea is a common erythematosquamous eruption, typically presenting along the cleavage lines of the skin. A wide spectrum of atypical manifestations may challenge even the most experienced physician. Here we report a rare case of a suberythrodermic pityriasis rosea with gigantic plaques after an influenza vaccination, and we discuss the possible triggers of atypical manifestations of such a common dermatological disease in the setting of an altered immunity.