Beyond the follicle

Every specialty starts with a simplification. Ours was the hair follicle.

Over time, we came to think of the follicle as a small organ in its own right: cyclical, self-renewing, immune-privileged, with its own stem cells and its own hormonal responses. This was a useful way to think about hair. It gave us minoxidil and finasteride, the trichogram, and the follicular unit as something that could be moved from one part of the scalp to another. It also allowed us to study hair loss for years without looking very closely at the person losing the hair.

The papers in this issue suggest that this is changing.

Consider the proposal that early patterned hair loss may involve an acquired increase in androgen sensitivity rather than an inherited one. The hypothesis is that reactive oxygen species lower the threshold of the androgen receptor, so that even normal hormone levels produce an exaggerated response. Whether this is correct remains to be established, and it will need prospective work. But the idea deserves attention, because it moves part of the cause from genes towards environment and lifestyle. Unlike our genes, at least some of these factors can be modified.

The report on iron deficiency makes a related point in simpler form. Hair diameter variability, black dots, and broken hairs usually point us towards a diagnosis. When they improve after iron replacement, we are reminded that trichoscopy tells us what the hair looks like, not always why.

The study of breakfast habits and exercise before breakfast is small and cannot establish cause and effect. Still, lifestyle factors are now being examined seriously in metabolic disease, and it is fair to ask whether they matter in hair disease as well.

On treatment, the trial of topical tofacitinib in children with patchy alopecia areata is encouraging. It asks whether JAK inhibition can be delivered to the affected skin while limiting systemic exposure. The results at 16 weeks are promising. We still need to know how long the response lasts, what happens after treatment is stopped, and what repeated use does over years in a growing child.

Some caution is also needed, particularly in regenerative medicine. Hair loss is visible, and the patient sees it every morning. That makes this an easy market for treatments that run ahead of their evidence. The review of exosome therapy states the problem clearly: the science of extracellular vesicles is genuinely promising, but not every product sold as an “exosome” has been adequately characterized. Before using such a product, we should ask about its composition, nanoparticle characterization, manufacturing standards and regulatory status.

Two papers remind us that the procedure itself matters. A prolonged episode of presyncope during hair transplantation shows that an elective operation in a healthy person is still an operation. And graft storage, usually treated as a waiting period between harvesting and implantation, is presented here as an active step with its own variables: hydration, order, counting, inspection, and handling.

The follicle has not lost its central place. It has simply been put back among the things that surround it — metabolism, lifestyle, immunity, regenerative biology, and the ordinary craft of surgery.

The follicle was never really alone. We only studied it that way.

Dr. Somesh Gupta

Editor-in-Chief

Journal of Hair Restoration and Regenerative Medicine