The authors complement the fi rst article on the approach of dermatological aesthetic hair treatments. This article addresses the ultimate hair straightening with major straightening legalized – sodium, lithium and guanidine hydroxides and ammonium thioglycolate –, their differences, mechanisms of action, indications and safety to human health. Besides these straighteners, we discuss the illegal and indiscriminate use of hairdressers salons in Brazil in the group of aldehydes (formaldehyde and glutaraldehyde) for smoothing hair. This study focuses its legal implications and public health, carcinogenic potencial and the identification of such filings with ANVISA. Also studied the shampoos and conditioning agents indicated for treatment of the hair shaft. Finally, we discuss the implications of hair care in general health of the hair shaft and the scalp.

The trichogram is an easy and semi-invasive method, useful for evaluating different types of hair loss in daily practice. To date, there is no standardized methodology on how to collect and perform the exam. The use of a liquid interface between the slide and the coverslip to read the trichogram under optical microscopy varies widely in the literature. Among the alternatives, transparent enamel base coat is an inexpensive, accessible, and practical option, providing the examiner with proper visualization of the hair shafts with minimal air bubbles formation.

Keywords: Alopecia; Hair diseases; Scalp dermatoses

Although little reported in daily practice, the use of systemic retinoids can cause changes in the shape, color, and texture of hair shafts. We report a case of a patient treated with isotretinoin for acne vulgaris who experienced new growing curly hair. Such hair changes are recognized during therapy with oral retinoids; however, isotretinoin-induced modifications on the hair fiber curvature are extremely rare.

Keywords: Hair; Isotretinoin; Pharmacological treatment