Alopecia areata risk factors: who is more likely to get it and why

What alopecia areata is

Alopecia areata happens when the immune system attacks hair follicles, the structures in skin that form hair. Hair can be lost from any part of the body, but the disease usually affects the head and face. Hair typically falls out in small, round patches about the size of a quarter, though in some cases the loss is more extensive. Most people with the disease are healthy and have no other symptoms (NIAMS).

NIAMS describes three main types (NIAMS):

• Patchy alopecia areata, the most common type, with one or more coin-sized patches on the scalp or other parts of the body.
• Alopecia totalis, with loss of all or nearly all of the hair on the scalp.
• Alopecia universalis, a rare type with complete or nearly complete loss of hair on the scalp, face and rest of the body.

There is no score or calculator on this page; the factors below are the ones NIAMS names.

Who is more likely to get alopecia areata

Anyone can have alopecia areata. Men and women both get it, and it affects all racial and ethnic groups. It can begin at any age, but most people get it in their teens, twenties or thirties. When it starts in children younger than 10, it tends to be more extensive and progressive (NIAMS).

NIAMS names these factors (NIAMS):

• Family history. Having a close family member with the disease may raise your risk, but many people with it have no family history.
• Genes. Scientists have linked a number of genes to the disease, many of them important for how the immune system works.
• Certain autoimmune diseases, such as psoriasis, thyroid disease (see hypothyroidism and hyperthyroidism risk factors) or vitiligo.
• Allergic conditions, such as hay fever and atopic dermatitis (see eczema risk factors).

Emotional stress or an illness may bring on alopecia areata in people who are at risk, but in most cases there is no obvious trigger (NIAMS).

What causes it

The immune system mistakenly attacks hair follicles, causing inflammation. Researchers do not fully understand what causes this attack, but they believe both genetic and environmental (non-genetic) factors play a role (NIAMS).

Symptoms and what can happen next

It typically begins with sudden loss of round or oval patches of hair on the scalp, but any body part can be affected, such as the beard area, eyebrows or eyelashes. Short broken hairs that are narrower at the base ("exclamation point" hairs) are often seen around the edge of a patch, and there is usually no rash, redness or scarring. Some people feel tingling, burning or itching just before the hair falls out. Some people also get nail changes such as pits (tiny dents), especially those with more extensive hair loss (NIAMS).

After a bare patch appears, the hair may regrow within a few months (sometimes white or gray at first), new patches may form, patches may join, or, less commonly, all body hair may be lost. In most cases the hair regrows, but there may be later episodes. Hair tends to regrow on its own more fully in people with less extensive hair loss, a later age of onset, no nail changes and no family history of the disease (NIAMS).

Other causes of hair loss

Not all hair loss is alopecia areata. MedlinePlus says losing up to 100 scalp hairs a day is normal, and that hair loss can also come with aging, certain diseases such as thyroid problems, diabetes or lupus, certain medicines or chemotherapy, stress, a low protein diet, family history and poor nutrition (MedlinePlus). Other conditions can cause hair to fall out in the same pattern as alopecia areata, which is why a doctor may order blood tests or a skin biopsy (NIAMS).

Diagnosis

Doctors usually diagnose alopecia areata by examining the areas of hair loss and your nails, looking at your hair and follicle openings with a handheld magnifying device, and asking about your medical and family history (NIAMS).

Treatment and living with alopecia areata

There is no cure, but treatments can help hair grow back more quickly (NIAMS). For many people hair grows back without treatment, and people with milder cases may not need any. Janus kinase (JAK) inhibitors are approved to treat adults with severe alopecia areata, and medicines approved for other conditions, such as corticosteroids (for example, injections for patchy alopecia areata) and immunosuppressants, may also be used. A doctor weighs your age and the extent of hair loss (NIAMS).

The disease does not cause physical disability but may affect well-being. Stress may be higher, and depression and anxiety are more common in people with alopecia areata; a mental health professional can help. NIAMS also suggests sunscreen on bare areas, wigs, hats or scarves to protect the scalp, glasses to shield the eyes if eyebrows or eyelashes are lost, and regular visits to a primary care doctor, because people with alopecia areata have a higher risk of diseases such as thyroid disease, atopic dermatitis and other autoimmune diseases (NIAMS). See depression and anxiety risk factors.

Common questions

Is alopecia areata genetic?

Genes play a role: a close family member with the disease may raise your risk and scientists have linked a number of genes to it, but many people have no family history (NIAMS).

Is alopecia areata an autoimmune disease?

Yes. NIAMS describes it as a disease in which the immune system mistakenly attacks hair follicles (NIAMS).

Can stress cause alopecia areata?

Emotional stress or an illness may bring it on in people who are at risk, but in most cases there is no obvious trigger (NIAMS).

Does the hair grow back?

In most cases it does, though later episodes can happen, and recovery is unpredictable (NIAMS).