Alopecia areata

• 1. Introduction

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  Alopecia areata, also called spot baldness, often announces itself with a single bald patch about the size of a coin. The skin underneath is unscarred and looks perfectly ordinary. The person is generally otherwise healthy. Yet hair is leaving some or all areas of the body.

  For some people the patch fills in again and the episode is over. For others the loss spreads far beyond that first spot. Nothing about the early signs reliably tells which path lies ahead.

  This documentary follows the questions that condition raises. What is going wrong inside the body when hair vanishes this way? Why would the body attack its own tissue? Why is the outcome so unpredictable from one person to the next? And where did such an odd name come from?

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• 2. Why The Body Turns

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  Each growing hair follicle is normally kept safe from the immune system, a protection known as immune privilege. Alopecia areata is believed to begin when that protection is breached. T cell lymphocytes then cluster around the affected follicles. The resulting inflammation suppresses or stops hair growth. The target is the anagen follicle, the kind that is actively growing hair. The condition is recognized as a type 1 inflammatory disease, and it is not contagious. A few babies have even been reported as born with congenital alopecia areata.

  Family history is a risk factor. Among identical twins, if one is affected, the other has about a 50% chance of also being affected. A study of families with two or more affected members identified at least four regions of the genome likely to hold the responsible genes. The condition shares genetic risk factors with rheumatoid arthritis, type 1 diabetes and celiac disease. It may be the only visible manifestation of celiac disease.

  In 2010, a genome-wide association study found 129 single nucleotide polymorphisms associated with alopecia areata. The genes involved help control the activation and proliferation of regulatory T cells. They also include interleukin-2, its receptor A, cytotoxic T lymphocyte-associated antigen 4, Eos and the human leukocyte antigen. Two more genes, PRDX5 and STX17, are expressed in the hair follicle itself. A metabolic defect in endogenous retinoids is described as a key part of how the disease develops.

  In most cases there is no obvious trigger, though psychological stress and illness are possible factors in people at risk. Smokers face a higher risk, potentially because tobacco drives Th17-mediated inflammation in the follicles. Obesity is also associated with higher risk, likely because adipokine dysregulation promotes chronic low-grade inflammation. Sleep disorders have been linked to the condition in some research, though the findings remain inconclusive. A psychodermatological connection is also noted, in which poor mental well-being, low self esteem and mental disorders may act as triggers.

  Vaccines are a newer and more tentative thread. One small study observed hair loss worsening in three patients after COVID-19 mRNA vaccinations from Pfizer-BioNTech and Moderna. Their average age was 30.6 years, compared with 37.2 years in unaffected individuals, and the worsening came within two weeks. Similar cases were reported with the AstraZeneca and Johnson & Johnson vaccines. Flares have also followed SARS-CoV-2 infection itself, and in that study the only worsening among non-vaccinated patients came after a COVID-19 infection. Causality remains unclear, and the findings are presented as a reason for further research into vaccination and disease progression.

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• 3. Reading The Signs

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  Doctors look for exclamation point hairs around the edge of a bald patch. These hairs are very short, and each one is narrower toward its base, giving it the shape of an exclamation mark. The patches themselves are usually round or oval. The area may tingle or feel mildly painful, and the hair tends to fall out over a short period, often more on one side of the scalp than the other.

  A gentle tug test adds a clue. In healthy hair, at most a few strands come out, and they do not come from one zone more than another. With alopecia areata, hair pulls out more easily along the edge of the patch, where the immune system is already attacking the follicles.

  The nails can carry signs too. They may show pitting or trachyonychia. A related condition called onychoptosis defluvium, also known as alopecia unguium, involves the nail being cast off entirely.

  Diagnosis usually rests on clinical features alone. Discrete areas of hair loss surrounded by exclamation mark hairs are often enough, and reddening of the skin called erythema is sometimes present. Trichoscopy, a close examination of the scalp, can help by showing regularly distributed yellow dots, small exclamation-mark hairs and black dots, which are destroyed hairs at the follicle opening.

  A biopsy is rarely needed. When one is done, pathologists may see lymphocytes gathered around the base of the follicle in a pattern described as a "swarm of bees". They may also see a shift in the ratio of anagen to telogen follicles toward telogen. In inactive disease, no inflammatory infiltrates are sometimes found at all.

  The pattern of loss gives the condition its vocabulary. Alopecia areata monolocularis means baldness in only one spot, while multilocularis means several areas. Diffuse alopecia areata thins hair over the whole scalp. Ophiasis is loss in a wave shape around the circumference of the head, and alopecia areata barbae is limited to the beard. Alopecia areata totalis is loss of all scalp hair, and universalis is loss of all body hair, including pubic hair. Both of those last two forms are rare.

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• 4. Odds Of Regrowth

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  In more than 50% of cases of sudden-onset patchy disease, hair regrows within a year. For patients with only one or two patches, that recovery rate reaches up to 80%. The picture is less hopeful at the far end of the spectrum. Among people who lose all their body hair, fewer than 10% recover.

  Many people have more than one episode over a lifetime. In many patients, loss and regrowth happen at the same time across several years. Hair that grows back and falls out again later may not signal a recurrence at all. It can instead reflect a natural cycle of growth and shedding from a relatively synchronised start, a pattern that fades over time. Episodes before puberty, however, predispose a person to chronic recurrence.

  No bodily function is lost, and the main effects are psychological, in the form of lost self-image. Those effects can be severe. Because hair changes appearance so visibly, people with the condition may experience social phobia, anxiety and depression.

  The physical costs are smaller but real. A bare scalp burns more easily in the sun. Keratin forms both hair and nails, which is why patients may also have aberrant nail formation. Who carries this burden, and how heavily, turns out to vary across populations.

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• 5. Who Gets It

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  About 0.15% of people are affected at any one time, and roughly 2% are affected at some point in life. Onset is usually in childhood, though it can also appear in the late teenage years or young adulthood. It can strike at any age. Females are affected at higher rates than males.

  Patients also tend to have a slightly higher incidence of immune-related conditions. These include asthma, allergies, atopic dermatitis and hypothyroidism.

  The burden is not spread evenly across groups. Studies indicate that people of Asian descent face the highest risk, with nearly 6 cases per 100 people. Among White individuals the figure is fewer than 2 cases per 100. People living in urban or economically disadvantaged areas are more likely to develop the condition. The effects differ as well, and individuals of Black descent with alopecia areata are more likely to experience anxiety and to require medical leave from work.

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• 6. Established Treatments

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  No cure is known, and none of the existing options is curative or preventive. Judging a treatment is hard because patchy hair loss often regrows spontaneously. Small lesions in particular tend to regrow on their own.

  A 2020 systematic review found greater than 50% regrowth in 80.9% of patients treated with 5 mg/mL triamcinolone injections. A Cochrane-style review published in 2019 found that 5% topical minoxidil was more than eight times more associated with greater than 50% regrowth at 6 months, compared with placebo. Steroid injections are commonly used where bald areas on the head are small, and especially where eyebrow hair has been lost. Whether they work is uncertain.

  Corticosteroid creams are less effective and take longer to work. Topical corticosteroids frequently fail to enter the skin deeply enough to reach the hair bulbs, which are the real target. In severe hair loss, the corticosteroids clobetasol and fluocinonide, given as an injection or cream, have had limited success. Oral corticosteroids may reduce hair loss, but only while they are taken, and they can cause serious side effects.

  Other medications have been tried, sometimes in combination. They include mometasone ointment sold as Elocon, the irritants anthralin and topical coal tar, and topical immunotherapy with ciclosporin. For more severe cases, studies show promising results from the immunosuppressant methotrexate, alone or alongside corticosteroids. No single treatment works in every case, and some people respond to none.

  When alopecia areata appears alongside celiac disease, a gluten-free diet allows complete and permanent regrowth of scalp and body hair in many people. Others still see remissions and recurrences. Sunscreen, head coverings against cold and sun, and glasses when eyelashes are missing are also recommended.

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• 7. New Drugs And Experiments

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  In 2014, preliminary findings showed that oral ruxolitinib restored hair growth in three people with long-standing and severe disease. The US Food and Drug Administration had approved the drug for the bone marrow disorder myelofibrosis. It belongs to a class called Janus kinase inhibitors, and that result pointed a new direction.

  In March 2020, the FDA granted breakthrough therapy designation to baricitinib, and it authorized the drug for severe alopecia areata in June 2022. Baricitinib blocks the JAK1 and JAK2 subtypes. Its efficacy rate was 32%, measured as people with 50% hair loss reaching 80% scalp coverage in 36 weeks. Ritlecitinib, sold as Litfulo, was approved in the United States in June 2023. Deuruxolitinib, sold as Leqselvi, followed in July 2024.

  Stranger experiments are underway. Fecal matter transplants have been shown to reverse the condition with long lasting results. Some patients even grew additional hair on the arms and face, and grey hairs regained colour. This supports the idea that gut microbiota play a part in hair loss.

  Hair transplantation has been tried for chronic local disease, with case reports since the early 2000s. Because the disease is autoimmune and relapses, it is one of the biggest question marks before surgery. A long-term follow-up reported that transplanted eyebrow hair fell out again when the disease recurred. Earlier studies did not mention this, perhaps because their follow-up was too short.

  Regenerative stem cell therapy has been investigated for vaccine-associated alopecia. A clinical case report described a patient after COVID-19 vaccination who received autologous CD34+ hematopoietic progenitor cells together with umbilical cord blood-derived mesenchymal stem cells. Hair density recovered progressively over 12 weeks, without significant adverse effects.

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• 8. A Fox, A Patch, A Verse

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  Physicians going back to Hippocrates have used the word alopecia, which comes from the Greek alopex, meaning fox. The name was inspired by the fur loss seen in foxes with mange. The second word, areata, comes from the Latin area, meaning a vacant space or patch.

  Some have also looked for the condition in scripture. Alopecia areata and alopecia barbae have been identified by some as the biblical nethek, part of the larger tzaraath family of skin disorders discussed in chapter 13 of the Book of Leviticus.

  Today the condition has many public faces. NASCAR driver Joey Logano and obstacle athlete Kevin Bull have some form of it. So do politicians Peter Dutton and Ayanna Pressley, and K-pop singer Peniel Shin of BtoB. The list continues with actors Christopher Reeve, Anthony Carrigan, Greg Grunberg and Alan Fletcher. Actresses Jada Pinkett Smith, May Calamawy and Lili Reinhart are on it too. Molly Tuttle serves as a spokesperson for the National Alopecia Areata Foundation.

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