Alopecia areata
Hair lost in defined patches, usually without any change to the skin. It is an autoimmune condition, it is unpredictable, and it needs a doctor as well as a trichologist.
01 What it is
Alopecia areata is an autoimmune condition in which the immune system responds to the hair follicle and hair stops being produced from it. The follicle itself is usually not destroyed, which is why regrowth is possible, though whether, when and for how long varies enormously between people, and nobody can predict it reliably.
It most often appears as one or more smooth, round or oval patches, most commonly on the scalp but possible anywhere hair grows, including the beard, eyebrows and eyelashes. Less commonly it presents as diffuse thinning across the whole scalp, as loss of all scalp hair (alopecia totalis), or of all body hair (alopecia universalis).
It is not caused by anything you did. It is not contagious. It is not, in itself, dangerous, which is often the least helpful thing anyone says to someone who has just found a patch.
02 Recognition
What people usually notice
- A smooth bald patch found by accident, while washing, parting the hair, or by a hairdresser.
- Skin in the patch that looks normal: no scaling, no redness, no scarring, sometimes slightly pale.
- Short broken hairs at the edge, narrower at the base than the tip.
- Tingling, itching or a mild burning sensation in an area shortly before hair goes.
- Ridging, pitting or roughness of the fingernails.
- Patches that fill in while new ones appear elsewhere.
03 Contributors
What may contribute
Grouped by how well supported each one is. That distinction matters more than the list itself.
Well established
- It is autoimmune in mechanism: the immune response to the follicle is the accepted explanation.
- There is a genetic component; a family history of alopecia areata or other autoimmune conditions is more common in people who develop it.
- It is associated with other autoimmune conditions, particularly thyroid disease and vitiligo.
Commonly associated
- Onset following a significant physical or emotional stressor is frequently reported, though the relationship is not straightforward and stress is not a cause in any simple sense.
- Low iron stores and vitamin D insufficiency are often found alongside it, worth identifying and correcting, but not established as causes.
- Atopic conditions such as eczema, asthma and hay fever occur more often in people with it.
Debated or unsupported
- Specific dietary triggers. Individual foods are widely blamed online; the evidence for any one of them causing or curing alopecia areata is weak.
- “Immune-boosting” supplements. In an autoimmune condition the logic is questionable, and the evidence is not there.
- Most topical products marketed for it. Some are harmless, few are studied, none are a substitute for a conversation with a dermatologist.
04 Uncertainty
What we don’t know
- Why it starts when it does, in the person it starts in.
- Why some people have a single episode that resolves and others have a relapsing course over decades.
- Why it responds to treatment in some people and not in others with apparently similar presentations.
- How much of the reported link with stress is causal, and how much is that people remember stress when looking for an explanation.
Worth doing first
When to bring a doctor in
- Any new patch of hair loss should be assessed by a doctor, ideally a dermatologist, to confirm what it is. Several other conditions can look similar and are treated very differently.
- If the skin in the patch is red, scaly, scarred, shiny or sore, this needs medical assessment promptly. Alopecia areata usually leaves the skin looking normal.
- If it is spreading quickly, or affecting eyebrows, eyelashes or the whole scalp.
- If it appears in a child.
- If you have symptoms that could suggest thyroid disease or another autoimmune condition: fatigue, weight change, temperature intolerance, joint pain.
If any of this applies, see a doctor first. It’s the quickest way to an answer. Bring what they tell you back to me and we’ll work out what it means for you.
05 Consultation
What a consultation can explore
- Your full history, including timing, other health events, and any family pattern.
- The condition of the scalp skin and the hair around the affected areas.
- What has changed since it started, and what has stayed the same.
- Blood results you already have, and what might be worth asking your doctor about.
- How to look after the scalp and the remaining hair without making things worse.
- Practical questions: coverage, hair handling, sun protection on exposed skin, what to expect from regrowth if it comes.
- The part of it nobody asks about, which is what it is doing to you.
Alopecia areata sits firmly in medical territory. I work alongside dermatology, not instead of it. What I can offer is time, context, scalp and hair care, and help making sense of what you have been told.
What happens next
Book
Online, wherever you are. You’ll receive a questionnaire and a prep sheet, and I read both before we meet.
We look at it properly
History, assessment, findings, and time for the questions you came with.
You get it in writing
A summary you can act on, sit with, or hand to your doctor.
This page describes what people commonly experience. Reading it isn’t the same as having someone look at your situation properly, and it can’t tell you which of these you have. That’s what the consultation is for.
Sources and further reading
- DermNet Alopecia areata
- British Association of Dermatologists Alopecia areata: patient information leaflet
- American Academy of Dermatology Alopecia areata: diagnosis and treatment
- NHS Alopecia areata
Written by Brigita Deveikaite, certified trichologist (VTCT Skills (ITEC) Level 4 Certificate in Trichology for Hairdressers, Trichocare). Last reviewed . This page is educational and is not a diagnosis.