Dissecting hair breakage in alopecia areata: the central role of dysregulated cysteine homeostasis

This review article examines the role of dysregulated cysteine homeostasis in hair breakage associated with Alopecia Areata (AA). Cysteine is essential for hair shaft stability through disulfide bond formation, and disruptions in its metabolism can lead to hair fragility and breakage, early indicators of AA. The review suggests that aberrant cysteine metabolism may be linked to autophagy, ferroptosis, immunity, and psychiatric symptoms, offering potential therapeutic strategies. It also discusses cysteine's role in synthesizing antioxidants like glutathione and metallothionein, which protect against oxidative stress and support keratin production. The article proposes that interventions such as N-acetylcysteine supplementation could be beneficial. Additionally, it highlights that psychological symptoms in AA patients might be secondary complications, with stress-related hormones potentially playing a primary role in AA development. Further research is needed to validate these hypotheses and understand the pathophysiology of AA.