INTRODUCTION
While chemotherapy-induced alopecia is one of the most well-known medication adverse effects (having an estimated incidence of 65%),1 numerous reports suggest that hair structure can be more subtly altered by various systemic medications. Many medication classes are reported to lead to profound changes in hair color and texture.2 Although there are studies summarizing the effects of systemic medications on hair loss and color, medication-induced hair texture changes are seldom reported and are poorly characterized in literature. In fact, most discussions of hair texture changes after medications are relegated to the internet, where patients have coined the term "chemo curl" to describe a common change after chemotherapy. The most commonly reported texture changes include new regrowth in a curly, kinky, or wavy pattern. More specifically, curling of hair involves twisting of the hair shaft around a central axis, kinking involves sharper twists or bends, and waving is defined as an increased number of coils and oscillations per unit length.
To the best of our knowledge, there are currently no comprehensive summaries of medication classes that can induce texture changes. To address this paucity of data, this systematic review aims to 1) identify the most commonly implicated medication classes, 2) report the frequency and duration of these changes, and 3) highlight potential mechanisms of the observed hair texture alterations. With this knowledge, health care providers can offer better anticipatory guidance and counseling for patients on these medications.
To the best of our knowledge, there are currently no comprehensive summaries of medication classes that can induce texture changes. To address this paucity of data, this systematic review aims to 1) identify the most commonly implicated medication classes, 2) report the frequency and duration of these changes, and 3) highlight potential mechanisms of the observed hair texture alterations. With this knowledge, health care providers can offer better anticipatory guidance and counseling for patients on these medications.
MATERIALS AND METHODS
A primary literature search was conducted in August 2021 using the PubMed and Cochrane databases with the following search terms: 1) "[medication name]" AND "hair*" AND ("curl*" OR "texture" OR "pili torti"); where "[medication name]" includes every generic anti-cancer drug from Association of Community Cancer Center's list of drug names; 2) ("Antineoplastic Agents"[Mesh] OR "isotretinoin"[Mesh] OR "acitretin"[Mesh] OR "valproate" OR "immunotherapy"[Mesh]