What Is Alopecia Areata?
Alopecia areata is an autoimmune condition in which the immune system attacks the hair follicles, causing them to enter a premature resting phase and stop producing hair. It affects approximately 2% of the population at some point in their lives and can occur at any age.
It typically presents as one or more well-defined round or oval bald patches on the scalp with smooth, normal-looking skin underneath. Characteristic "exclamation mark" hairs — short hairs that are narrow at the base, wider at the tip — may be visible at the patch margins. Importantly, alopecia areata does not permanently destroy follicles in most cases, meaning regrowth is biologically possible even after prolonged episodes.
Distinguishing Alopecia Areata From Other Hair Loss
Alopecia Areata
- Patchy, well-defined bald areas
- Smooth skin in the patch
- No scaling, redness, or scarring
- Can affect eyebrows, eyelashes, beard
- Autoimmune — follicles intact, regrowth possible
Pattern Hair Loss (Androgenetic Alopecia)
- Gradual, diffuse thinning over years
- Follows predictable pattern (frontal/crown)
- Driven by DHT sensitivity
- Scalp visible through thinning hair
- Does not respond to steroid injections
Correct diagnosis matters before any treatment is initiated. Steroid injections are appropriate for alopecia areata specifically — not for pattern hair loss, telogen effluvium (diffuse shedding after illness or iron deficiency), or scarring alopecias. Your GP will confirm the diagnosis at your assessment appointment.
How Intralesional Steroid Injections Work
Corticosteroid is injected directly into the dermis of the affected scalp using a fine needle. The steroid suppresses the local T-cell-mediated immune attack on hair follicles in that area. By reducing this inflammation, follicles that have been held in a dormant state are released to re-enter the active (anagen) growth phase.
Injections are placed in a grid pattern across the patch — typically 0.1ml at each point, spaced approximately 1cm apart. A single session on a patch the size of a 50-pence piece may involve 8–15 injection points.
Treatment Schedule
Sessions are typically spaced 4–6 weeks apart. Most patients undergo a course of 3–6 sessions before the response is formally assessed. What to expect:
- Weeks 4–8: Fine, pale (unpigmented) vellus hairs may begin to appear in the treated area — this is an early sign of follicle reactivation
- Weeks 8–16: Vellus hairs gradually mature into thicker, pigmented terminal hairs
- Months 3–6: Most of the expected regrowth from a responsive course becomes visible
Important to know: Steroid injections suppress the immune attack in the treated area but do not address the systemic autoimmune tendency. New patches can develop elsewhere on the scalp even while existing patches regrow. This is normal and does not mean treatment has failed.
When to Consider Referral
Intralesional steroids are most appropriate for patchy alopecia areata affecting less than 50% of the scalp. If patches are very extensive, if alopecia totalis or universalis is present, or if a full course of injections fails to produce regrowth, your GP will refer you to a consultant dermatologist or trichologist. Other treatments — including topical immunotherapy (diphencyprone) and JAK inhibitors — may be considered in specialist care.
Book an Assessment
Lambert Medical Practice offers GP-led assessment and treatment for alopecia areata. Diagnosis is confirmed at your first appointment, and treatment can begin at the same visit where appropriate.