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Alopecia Areata: Causes, Diagnosis & Treatment
Dr. Michael May (FRCS)
Medically reviewed by
Dr. Michael May (FRCS)
Updated on March 8, 2024

Alopecia areata is a common type of hair loss, which affects around 1 in every 170 adults in the UK [1]. That means there are more than 300,000 people in the UK with alopecia areata. Despite so many people having his condition, there’s still a lot of confusion regarding diagnosis and treatment.

Learn more here about alopecia areata, including causes, risk factors, diagnostic tests, and treatments.

Table of Contents

What is alopecia areata?

Alopecia areata (AA) is a type of non-scarring hair loss characterised by patchy areas of baldness. Unlike scarring alopecia, it’s rarely itchy or flaky, and the edges of the patches are smooth and round. It can affect any area of the body, including the scalp, beard, eyebrows, eyelashes, armpits, and chest. Alopecia areata that affects the beard is known as alopecia barbae.

Most (though not all) researchers agree that alopecia areata is an autoimmune condition [2]. That means it’s caused by white blood cells attacking the hair follicles by mistake. Damage to the follicle will cause it to stop producing hair, leading to the characteristic bald spots in this condition as hair falls out.

Almost half of all AA patients have mild cases that clear up within a year [3]. However, many go on to experience recurring alopecia areata, with new patches appearing after the original ones have regrown. Up to a quarter of patients develop symptoms of severe alopecia areata that ultimately lead to alopecia areata totalis (total loss of scalp hair) or alopecia areata universalis (loss of all body hair) [3]. Some people also experience ophiasis alopecia (a bald band across the back of the scalp).

The impact of alopecia areata

Alopecia areata doesn’t usually have a direct effect on your overall health. However, like any type of hair loss, it can lead to significant emotional and psychological distress [4, 13]. The more severe or extensive the hair loss, the greater these psychological effects tend to be [5]. One study found that two-thirds of patients with alopecia areata experienced hair loss-related depression, while almost three-quarters reported feelings of anxiety [13].

Fortunately, these patients reported relatively mild forms of depression and anxiety. But psychological effects can be extensive, especially given the unpredictable nature of alopecia areata. Other patients reported avoiding social situations, feeling embarrassed and ashamed, and using wigs to conceal their hair loss [14]. Other hair loss statistics suggest that 40% of women with alopecia also reported having problems in their marriage as a result of their alopecia, while 63% said it had affected their career.

Treating alopecia areata isn’t always easy, and treatment itself can be emotionally taxing for some patients [3]. But the psychological impact of the condition means that you should discuss treatment options with a doctor or trichologist. Even if your hair regrowth journey is slow, cognitive behavioural therapy and other treatments may help you cope with your hair loss.

What causes alopecia areata?

Lack of clarity around the cause of alopecia areata has led to difficulty in treating the condition. While most researchers now agree that AA is an autoimmune condition, it’s not fully understood what causes the immune system to attack the hair follicles.

Recent research suggests that immune privilege may play a part [4]. Hair follicles are immune-privilege sites, meaning they have built-in mechanisms that spot and conceal certain antigens from the immune system, blocking unwanted immune responses. But if this immune privilege collapses, the follicles become susceptible to autoimmune attacks. Immune privilege collapse has been proposed as a likely cause of alopecia areata.

We don’t know exactly why immune privilege collapse happens, though it may be due to an inflammatory response that interacts with the hair follicles [2]. Many sufferers have a genetic predisposition to develop alopecia areata. Environmental triggers like viral and bacterial infections may also play a part [2, 3]. Some evidence also suggests that vitamin deficiencies may play a part in hair loss caused by AA.

Many famous people have come forward to reveal their experiences with alopecia areata in recent years, including Matt Lucas, Jada Pinkett Smith, Gail Porter, and Viola Davis. Learn more about female celebrities with hair loss and Matt Lucas’s alopecia journey.

What are the symptoms of alopecia areata?

Sudden patchy hair loss is the first and most obvious symptom of alopecia areata. Unlike other types of hair loss, such as male pattern baldness (also known as andogenetic alopecia), female pattern baldness, and telogen effluvium, AA almost always manifests as round patches of baldness.

alopecia areata example 1alopecia areata example 2

Images showing characteristic bald patches of AA patients. Image sources:; Adobe Stock

Other symptoms include:

  • Small broken hairs that look like exclamation marks — these can be difficult to spot on your own head
  • Red or discoloured nails
  • Brittle nails that split easily
  • Yellow, white, or black dots on the skin
  • Loss of hair elsewhere on the body, such as the beard or eyelashes

exclamation mark hairs example

Exclamation mark hairs. Image source: Alopecia: Evaluation and treatment

red nails alopecia areatasplit nails alopecia areata

1. Red nails in someone with AA. 2. Split, damaged nails in an AA patient. Image source:

yellow spots on skin alopecia areata

Yellow, white and black dots on the scalp of an AA patient. Image source: Dermoscopy findings of alopecia areata in an African-American patient

Alopecia areata has different symptoms to most other types of hair loss. Find out more about hair loss symptoms and causes.

Who is at risk of developing alopecia areata?

You’re most at risk of developing alopecia areata if you:

  • Are 25-40 years old
  • Are of non-white ethnicity — learn more about Asian hair loss
  • Have a close relative with AA
  • Suffer from asthma, hayfever, or allergies
  • Have Down’s syndrome
  • Have taken Nivolumab as a cancer treatment

Alopecia areata can develop in people of any age, though the first episode tends to occur in younger people. A UK study found that most people experience their first episode between the ages of 25 and 29 [1]. International research suggests onset usually occurs by the age of 40 [5]. Cases have been seen in people of all ages, including children as young as 1.

Both men and women are equally affected by AA [1, 2, 6]. However, there is some variation in terms of ethnicity. There tends to be higher prevalence in those of non-white ethnicity [1, 7].

Up to 42% of AA patients have a family history of the condition [2]. People with Down’s syndrome are also more likely to develop AA, further establishing a genetic link [2]. Alopecia areata has been linked to a mutation on chromosome 21, which most people with Down’s syndrome have 3 copies of, rather than 2 [8]. So this may explain the higher risk of developing AA for those with Down’s syndrome.

Other conditions that have been linked to increased risk of alopecia areata are asthma, hayfever, atopic dermatitis, allergies, eczema, and other autoimmune diseases . Taking Nivolumab, a drug used to treat certain types of cancer, may also increase the risk [11].

How long does alopecia areata last?

There’s no set timeframe for alopecia areata symptoms. In mild cases, the condition will clear up by itself within a few months to a year. In more severe cases, hair loss can last for months or even years. Sometimes, hair loss may worsen, leading to larger bald patches across the head, as well as alopecia totalis or alopecia universalis.

Recurring episodes are typical for many alopecia areata sufferers [2]. The unpredictable nature of the condition makes it difficult to manage and treat in the long-term, though there are many proposed treatments available.

How is alopecia areata diagnosed?

Because alopecia areata is so different from other types of hair loss, it’s usually fairly easy to diagnose. A hair and scalp exam will reveal the key symptoms, such as exclamation mark hairs and round bald patches. Other symptoms, such as diffuse hair loss, a widening parting, or a receding hairline, usually indicate pattern baldness, or other less common types of extensive hair loss.

That said, alopecia areata can be confused with trichotillomania. Trichotillomania is a condition in which the patient pulls out their own hair, leading to small bald patches across the head. It’s commonly associated with stress and anxiety-induced hair loss. Exclamation mark hairs, which often indicate AA, are also a symptom of trichotillomania [12]

To differentiate between these conditions, trichologists will ask questions about your stress levels and other lifestyle factors. They can also examine the exclamation mark hairs under a microscope to determine if the hair follicles examined are still in the anagen (growth) phase of the hair growth cycle. If so, it’s likely that trichotillomania is the cause, as AA hairs are no longer in the growth phase.

Your trichologist may also perform a scalp biopsy or blood test to rule out other underlying conditions that may be causing hair loss.

How to stop alopecia areata from spreading

The unpredictable spread of alopecia areata is a key area of concern for many patients. And because there are very few risk factors you can control, there’s not much you can do to stop alopecia areata from spreading.

You may be more at risk of recurrent or worsening AA if you first experienced the condition during puberty, have a family history, or suffer from allergies [4, 15].

The best way to protect your hair is to take good care of it. Eat a balanced diet, practise good haircare, and see a hair loss specialist who can help you manage the condition. Keeping the rest of your hair healthy may help you conceal thinning hair and hide your bald patches more easily. This can also ensure your hair is thick and healthy when it regrows.

What is the treatment for alopecia areata?

Treating alopecia areata is traditionally time-consuming and difficult because each patient’s prognosis and condition trajectory is so unpredictable, there’s no obvious treatment plan to follow. Up to 50% of patients recover with no treatment at all, so some doctors recommend waiting to see if your hair regrows spontaneously [3].

However, the medical community is becoming more proactive in establishing successful treatments for AA. In June 2022, the US Food and Drug Administration approved the JAK inhibitor Olumiant as the first systemic treatment for alopecia areata [16]. The drug can now be used to treat severe forms of the condition in the US. The drug is around 30% effective, making this a breakthrough treatment for severe AA sufferers. Pfizer is also developing an alopecia drug known as ritlecitinib.

While Olumiant has yet to be approved for treatment of AA in the UK, there are other treatments available [17]. These include:

  • Corticosteroid injections — these are injected near the balding areas of the scalp; hair regrowth may be seen within 4-6 weeks, and repeated injections may be necessary
  • Topical Minoxidil and Anthralin — these topical creams can be applied to the scalp. Only Minoxidil is suitable for children under 10
  • Contact immunotherapy — this treatment consists of causing a deliberate allergic skin reaction which suppresses the autoimmune reaction in the hair follicles [17, 18]
  • Methotrexate — this immunosuppressant drug may encourage hair growth in those with severe alopecia areata[19]
  • Antihistamines — anti-allergy drugs can also reduce the severity of atopic AA [9]

To treat alopecia areata, your doctor may also prescribe a combination of these treatments depending on the severity and extent of your hair loss.

Some men with alopecia areata opt for scalp micropigmentation (SMP). This is a cosmetic treatment that involves tattooing tiny dots of ink across the scalp to look like a full shaved head. SMP is an effective way to hide AA-related hair loss, but some people end up with scalp micropigmentation regrets if they rush into it. Take time to research all available treatment options before deciding which is best for you.

Can you get alopecia areata treatment on the NHS?

Because AA doesn’t directly impact your overall health, you can’t usually get treatment on the NHS. However, if your condition is triggered by an underlying problem such as asthma, your NHS doctor can treat this. Addressing the underlying problem may help reduce your AA symptoms.

Your GP may also be able to refer you to a trichologist, who can help you treat your alopecia privately.

What can you do to aid recovery?

Unfortunately, there’s not much you can do to aid your own recovery besides following your doctor’s advice. Alopecia areata recovery is often a waiting game, which can take its toll on your mental health.

Many patients find support and advice from other alopecia sufferers helpful. There are many patient support groups available around the UK where you can do things like talk with others about your hair loss conditions or even participate in events for Alopecia Awareness Month. These can help you adjust to and accept your hair loss while your treatment is ongoing. Find a support group at Alopecia UK.

Alopecia areata regrowth signs

If you’re anxious to regrow hair after an AA episode, you may be anxious to look for signs of regrowth.

The most common sign of hair regrowth is vellus hair. These thin hairs are likely to be a different colour to the rest of your hair (usually a greyish-white), but will eventually blend in as they grow [20].

It’s sometimes easy to mistake exclamation mark hair for vellus hair. However, exclamation mark hairs are usually a sign of continuing hair loss rather than regrowth [21]. They’re often shorter and spikier than vellus hairs, and taper towards the scalp (like an exclamation mark). A professional trichologist will be able to tell you if you have exclamation mark hairs or vellus hairs.

exclamation mark hairs examplevellus hairs example

1. Exclamation mark hairs. 2. Vellus hairs. Image sources: Alopecia: Evaluation and treatment; Medical News Today

What to do if you think you have alopecia areata

Alopecia areata can be worrying, as it’s difficult to know how severe or long-lasting your condition will be. Hair transplants for alopecia areata patients aren’t usually recommended, although some evidence suggests artificial hair transplants like Biofibre may work for people with alopecia totalis [21]. With many other treatments on offer, you may be able to restore your hair sooner than you think.

Get a diagnosis of your hair loss with a consultation at the Wimpole Clinic on Harley Street. Book your consultation so you can start your recovery from alopecia areata today.

Alopecia Areata: Causes, Diagnosis & Treatment, Wimpole Clinic

Dr. Michael May (FRCS)
Medically reviewed by Dr. Michael May (FRCS)Updated on March 8, 2024
The Wimpole Clinic offers FUE Hair, Beard & Eyebrow Transplants & Trichology.
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