RESUMO
Surgical facelifts and noninvasive techniques such as mesotherapy, hyaluronic fillers and botulinum toxin, among other procedures are widely used nowadays to reverse skin ageing and achieve rejuvenation effects. Secondary alopecia due to cosmetic procedures is a rare side effect and is poorly described in the literature. The mechanisms in which hair loss develops after an aesthetical procedure or surgical technique are not well known. The development of secondary scarring alopecia or non-scarring alopecia depends upon the interaction between different external factors, the individual host response and the extent of damage to the hair follicle anatomy. Current knowledge hints at the type of substance used, pressure to hair structures and vasculature due to the materials used, previously unknown or unaware hair disorder, and poor surgical techniques to be the main factors contributing to the development of secondary alopecia. Physicians and patients must be aware of all the substances used for the procedures and be attentive to any change in hair density or hair loss. Clinicians must have a low threshold to take biopsies if the risk of scarring alopecia may occur. Herein, we review the clinical, trichoscopic, histopathological findings and potential pathophysiological mechanisms of hair loss due to different aesthetic procedures.
