Can new treatment cure bald patches all over my head?

I've had alopecia areata for several years and have persistent large bald patches on my head. The steroid injections I was given made no difference, so I now wear a wig most of the time. I've heard there is a new JAK inhibitor treatment available. Does it work, what about side-effects, and can I get it on the NHS?

- Dr Rosemary Leonard

Alopecia areata is an auto-immune condition, where the body's immune system attacks and prevents the functioning of follicles where hair growth occurs, leading to bald patches which may occur on the scalp or in the beard area in men.

Occasionally the eyebrows and eyelashes are affected as well.

Though in many the patches are fairly small - about the size of a large coin - larger patches may appear, and in some, all the scalp hair is lost.