Is There a Role for Radiofrequency Devices in Hair?

Background: Radiofrequency (RF) devices are being increasingly used for cosmetic dermatology applications. Recent studies have reported an apparent dualistic nature of RF devices for hair, causing either removal or growth depending on the modality of RF. Materials and Methods: PubMed/MEDLINE and Web of Science searches were conducted in July 2022 according to PRISMA guidelines for studies discussing RF technology in hair applications (n = 19). Results: The majority of studies describe the utility of RF devices in removal of unwanted hair (n = 15). Bipolar RF has been used in combination with intense pulsed light for effective long-term removal of body and facial hair. The chromophore-independent method of energy delivery in RF makes it a viable add-on therapy for treating lighter colored hair and darker Fitzpatrick skin types. Monopolar RF is used for eyelash removal in patients with trichiasis. In contrast, fractional RF has been used to stimulate hair growth in patients with alopecia areata and androgenetic alopecia. Conclusions: Preliminary evidence supports the use of bipolar and monopolar RF devices for hair removal, while fractional RF appears to be an emerging technology for hair growth. Additional studies are needed to investigate the efficacy, mechanisms, and parameters of radiofrequency devices for various hair applications.

A systematic review on the lipid composition of human hair.

Hair lipid composition varies by ethnic hair type and by hair layer. Lipids in the cuticle, cortex, and medulla of the hair shaft provide a protective barrier to environmental and chemical damage, prevent hair breakage and desorption, and affect the elastic and tensile properties of hair. The aim of this systematic review is to provide an overview of the lipid composition and ethnic differences of human hair, effects of external damage on lipid content and properties, and changes in hair lipid composition associated with disease states. PubMed/MEDLINE was searched up to March 2021 according to PRISMA guidelines for articles discussing the lipid content of human hair and effects of physical, chemical, or environmental damage, and disease. Fifty-nine articles investigating the lipid content of hair were included for review. Lipids affect fluid permeability, hydration, strength, and texture of ethnic hair fibers. Lipid loss is accelerated by hair-damaging treatments such as bleach, dye, perm, straightening, and surfactant use, and sun and aging processes, leading to dehydrated, breakable, disordered, and dull hair. Diseases including acne, alopecia, and breast, gastric, prostate, lung, and rectal cancers display elevated hair lipid levels. Lipids are vital in protection against damage and maintenance of healthy hair. Further studies are needed to investigate the effects of lipids on the structural properties of ethnic hair, and changes in hair lipid composition with various dermatologic and systemic diseases.

Reflectance Confocal Microscopy, Optical Coherence Tomography, and Multiphoton Microscopy in Inflammatory Skin Disease Diagnosis.

BACKGROUND AND OBJECTIVES: Technological advances in medicine have brought about many novel skin imaging devices. This review aims to evaluate the scientific evidence supporting the use of noninvasive optical imaging techniques to aid in the diagnosis and prognosis of inflammatory skin diseases. STUDY DESIGN/MATERIALS AND METHODS: PubMed and Scopus were searched in September 2020 according to PRISMA guidelines for articles using reflectance confocal microscopy (RCM), optical coherence tomography (OCT), and multiphoton microscopy (MPM) in inflammatory skin diseases, excluding studies monitoring treatment efficacy. RESULTS: At the time of the study, there were 66 articles that addressed the utilization of noninvasive imaging in interface, spongiotic, psoriasiform, vesiculobullous, and fibrosing/sclerosing inflammatory skin dermatoses: RCM was utilized in 46, OCT in 16, and MPM in 5 articles. RCM was most investigated in psoriasiform dermatoses, whereas OCT and MPM were both most investigated in spongiotic dermatoses, including atopic dermatitis and allergic contact dermatitis. CONCLUSIONS: There is preliminary evidence to support the diagnostic potential of noninvasive optical imaging techniques in inflammatory skin diseases. Improvements in the devices and further correlation with histology will help broaden their utility. Additional studies are needed to determine the parameters for diagnostic features, disease differentiation, and staging of inflammatory skin conditions. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.