Hair, Pigment & Nails
Alopecia, unwanted hair, pigment disorders, and nail and sweat conditions.
Alopecia: Regrowing Hair by Its Biology
Hair loss looks like a single complaint but is really a dozen different diseases wearing the same face. The trick to treating it — and the reason so many patients are handed the wrong remedy — is that none of these conditions is truly about hair. They are about the follicle's clock: a rhythm of growth, regression, and rest that hormones, immune cells, stress, and inflammation each disrupt in their own way. Get the clock right and the drug almost chooses itself.
Hirsutism and Unwanted Hair: Turning Down the Androgen Signal
In the alopecia chapter, androgens shrink scalp hair until it vanishes. Here the same hormones do the opposite: they turn soft, invisible down into thick, dark, terminal hair — on a woman's chin, jaw, chest and abdomen, in the pattern of a man's beard. It is the mirror image of male-pattern balding, driven by the very same 5-alpha-reductase axis, and most often it is the outward sign of polycystic ovary syndrome. The drugs do not pluck the hair. They work far upstream — lowering how much androgen the body makes, or blocking the receptor it acts on — and then they wait out a full hair cycle for the result to show.
Pigment Disorders: Lightening Melasma and Repigmenting Vitiligo
Two patients sit in the same clinic with opposite complaints. One wants a brown mask across her cheeks to fade; the other wants milk-white patches on his hands to fill back in with colour. Both problems live in the same cell — the melanocyte — and both turn on the same rate-limiting enzyme, tyrosinase. Yet the drugs point in exactly opposite directions: one class quietly throttles the pigment factory, the other calls off an immune assault so the factory can reopen. Understanding pigment pharmacology means holding both goals in your head at once — and respecting that in both, the sun is either your ally or your saboteur.
Nails and Sweat: Onychomycosis and Hyperhidrosis
Two humble appendage complaints — a crumbling toenail and hands that drip — turn out to be masterclasses in pharmacology. The nail teaches you drug delivery: a keratin fortress so impenetrable that painting a drug on top rarely works, and cure usually means feeding an antifungal from the inside for months while the nail slowly grows out. The sweat gland teaches you the autonomic nervous system, and hides a genuine surprise: it is a sympathetic structure that runs on acetylcholine, the neurotransmitter of the parasympathetic side. That single quirk is why aluminium salts, anticholinergics and botulinum toxin all have a place in the same clinic.
