Condition

Alopecia Areata

Alopecia areata is an autoimmune condition that makes hair fall out in smooth, round patches. The immune system switches the follicle off rather than destroying it, so hair can come back - but it is unpredictable, and no one can tell in advance who will regrow and who will not.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
16:9 hero for Alopecia Areata. Never cropped: the tone strip and the corner logo depend on the full frame.

Start here

The first thing almost everyone asks me is whether this means something is seriously wrong with their health. For the great majority, no - alopecia areata is the immune system making a mistake about one target, the hair follicle. The harder truth is that it is unpredictable: a single patch on the back of the head often fills in within a year with or without treatment, widespread loss is much less certain, and what I can promise is that we treat it, and treat it again if it comes back. The emotional weight of this is not a side issue, so if it is affecting your sleep, your work or your mood, say so out loud.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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How commonAround 2 in 100 people have an episode at some point in their lives
Who gets itAny age and any sex. It often starts in childhood or in the twenties and thirties, and about half of people have their first episode before 21
Curable or managedManaged. Hair can regrow completely, but episodes often return, so this is treated in rounds rather than cured once
Prescription neededYes for active treatment. A single small patch is sometimes just watched, because many fill in on their own
Time to improveUsually three to six months before regrowth is clear, and longer for widespread loss

What It Is

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Alopecia areata is an autoimmune condition. The immune system, which normally attacks infections, targets the hair follicle by mistake. The result is one or more smooth, round bald patches that appear over days to weeks, with normal skin underneath - no rash, no scale, no scarring.

What matters is what the immune system does not do. It shuts the follicle down and forces the hair out, but it does not destroy it. The follicle stays alive under the skin, empty and switched off. That is why hair can regrow months or years later, sometimes with no treatment, and why a bare scalp here is different from a bare scalp in scarring hair loss.

How far it goes varies enormously. Most people have one or a few coin-sized patches. A smaller number lose all scalp hair, called alopecia totalis, and fewer still lose scalp and body hair including brows and lashes, called alopecia universalis. Nails are sometimes involved, with fine pitting or ridging.

It is not contagious, it is not caused by anything you did, and it does not affect general health.

Symptoms

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Round bald spots

Patchy

One or more smooth, coin-shaped bald patches that appear over weeks, most often on the scalp or beard. The skin underneath looks normal rather than scarred, red or scaly. Because the follicles are intact, regrowth is possible even after months of a patch sitting empty.
A band along the hairline

Ophiasis

Hair loss that runs as a band around the lower back and sides of the scalp rather than as a round patch. It tends to be more stubborn than scattered patches. The pattern matters because it changes what treatment is usually suggested.
Most or all of the scalp

Extensive

Loss that joins up until most of the scalp is bare, and in some people the eyebrows, lashes and body hair go too. It can come on quickly or build from smaller patches. This form is harder to treat and is usually handled by a dermatologist from the start.

Where It Shows Up

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Front view of a head with red marks across the scalp, on both eyebrows, around both eyes and along the beard area of the jaw and chin.
Scalp, beard, brows and lashes
The scalp is the usual place. It can also take the beard, the eyebrows and eyelashes, and body hair. Losing hair in more than one of these at once is common and does not mean the condition is more severe.
Back view of a whole body with red marks on the back of the head, behind both ears and along the nape of the neck. The rest of the body is clear.
The back of the head and the hairline behind the ears
A first patch often sits on the back of the head, where someone else notices it before you do. One stubborn pattern runs as a band around the lower edge of the scalp, behind the ears and along the nape.

What Happens in the Skin

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This is what is going wrong under the skin, in the order it happens. Click a step to see it.

How Alopecia Areata happens
Skin basics
BARRIEREPIDERMISDERMISHAIRSIGNAL0A NORMAL HAIR FOLLICLE1THE FOLLICLE LOSES ITS COVER2IMMUNE CELLS SWARM THE HAIR BULB3THE FOLLICLE SHUTS DOWN4THE FOLLICLE IS HELD SWITCHED OFF

A growing hair follicle keeps itself partly hidden from the immune system. Signals around the bulb at its base stop immune cells from recognizing it. That cover is what lets a hair grow for years without ever being attacked.

A growing hair follicle normally keeps itself partly hidden from the immune system, and in alopecia areata that cover slips so the follicle becomes visible to immune cells for the first time.

Immune cells gather around the base of the follicle and attack it, and under a microscope it looks like a swarm around the hair bulb. This is the step steroid injections and the JAK inhibitors are aimed at.

The follicle responds by switching itself off and letting go of its hair, which is why a bare patch can appear within days rather than over months.

The attack carries on and keeps the follicle off, but it does not destroy it. The structure stays alive under the skin, empty and waiting, which is why hair can come back months or years later. Almost everything on the lists below is pushing on this step.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Four things happen in sequence, and every treatment aims at one of them. First, the hair follicle loses what dermatologists call immune privilege - a growing follicle normally keeps itself partly hidden from the immune system, and here that cover slips (1). Second, immune cells gather around the base of the follicle and attack it; under a microscope it looks like a swarm around the hair bulb (2). Third, the follicle shuts down and releases its hair, which is why a patch can appear within days (3). Fourth, the attack keeps the follicle switched off, though the follicle survives underneath, which leaves the door open for regrowth (4).

Why it starts is not fully known. The genetic component is clear - risk is higher if a close relative has it, higher again in families with other autoimmune conditions such as thyroid disease or vitiligo. Something tips a susceptible immune system over, and infections and stress have been looked at hard without being pinned down.

In most people no cause is ever identified. That is unsatisfying, and it is also why searching for a personal explanation rarely leads anywhere.

Risk Factors

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Most of what makes alopecia areata more likely was set by your genes. No diet, product or habit has been shown to cause it, and hunting for one ends in blaming yourself.

Inherited
Family history
The clearest factor. A parent, sibling or child with it raises the risk, more so with other autoimmune conditions in the family.
Inherited
Down syndrome
Substantially more common than in the general population.
Other health conditions
Other autoimmune conditions
Thyroid disease, vitiligo, type 1 diabetes and celiac disease appear more often. Having one does not mean you will get the others.
Other health conditions
Eczema
Atopic dermatitis goes with alopecia areata, and people with both tend to have more extensive loss.
Age
Age of onset
It can start at any age, but early childhood onset is linked to more extensive, more persistent loss.
Possible triggers
Stress
Many people name a stressful period before their first patch, but it has been hard to prove. At most a trigger in someone already susceptible.

Course

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Alopecia areata is unpredictable. The follicle survives throughout, however long the hair has been gone, which is why treatment stays worth trying after a long gap.

First patchThe usual start
One or a few coin-sized bare patches

One or a few coin-sized patches, usually on the scalp.

Scalp
Several months to a yearRegrowth
Many patches fill in without treatment

Patches often fill in over several months to a year with no treatment. Fine white or pale hairs appear first, then thicken and take on color. White regrowth is normal, not a failed treatment.

Later episodesOver years or decades
One episode makes another more likely

One episode makes another more likely at some point, and many people cycle through loss and regrowth over decades.

A harder courseFeatures that predict it
More extensive, and slower to turn around

Loss starting in early childhood, loss over a large part of the scalp, a band running around the lower edges behind the ears, nail involvement, and a long history of episodes all point to a harder course. None is a verdict - people with extensive loss do regrow, sometimes years in.

Lower edges of the scalpBehind the earsNails
Total lossAlopecia totalis and universalis
The far end of the range

Alopecia totalis is all scalp hair, universalis is scalp and body hair. Spontaneous regrowth is less likely than from a single patch, and this is the group for whom the newer oral treatments changed what is on offer.

ScalpBody hair

What Makes It Better & Worse

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Alopecia areata runs in four steps — the follicle losing its cover, immune cells attacking the bulb, the follicle shutting down, and the attack keeping it switched off. Most flares arrive with no trigger anyone can name.

What is driving yours?

FATHAIRSIGNALBARRIEREPIDERMISDERMIS

A growing hair follicle normally keeps itself partly hidden from the immune system, and in alopecia areata that cover slips so the follicle becomes visible to immune cells for the first time.

Immune cells gather around the base of the follicle and attack it, and under a microscope it looks like a swarm around the hair bulb. This is the step steroid injections and the JAK inhibitors are aimed at.

The follicle responds by switching itself off and letting go of its hair, which is why a bare patch can appear within days rather than over months.

The attack carries on and keeps the follicle off, but it does not destroy it. The structure stays alive under the skin, empty and waiting, which is why hair can come back months or years later. Almost everything on the lists below is pushing on this step.

What helps

  • Oral JAK inhibitors Can regrow hair in very extensive loss, with monitoring and real risks.

What makes it worse

  • Severe or prolonged stress Often reported before flares, hard to prove.
  • An untreated thyroid problem Treating it does not regrow hair, but it is worth finding.

What helps

  • Steroid injections into the patch The fastest reliable option for a few patches.
  • Strong topical steroids Slower than injections, the usual choice for children.
  • Contact immunotherapy A deliberate mild allergy that distracts the immune system.

What helps

  • Topical minoxidil Not a treatment on its own, but it supports regrowth.
  • Sun protection on bare scalp Sunscreen, a hat or a scarf.
  • Wigs, toppers, brows and lashes Not a lesser option. Many US insurers cover a wig with a prescription.
  • Talking to someone about it Anxiety and low mood are well documented, and support groups exist.

What makes it worse

  • Sunburn on bare scalp Skin never exposed burns fast and marks for months.

What helps

  • Time and watchful waiting A large share of single patches fill in within a year.

What makes it worse

  • Assuming a patch will sort itself out Waiting costs most when loss is spreading.
  • Stopping treatment at first regrowth Regrowth means the attack is suppressed, not over.
  • Chasing unproven cures Months lost while a spreading case goes untreated.

How These Treatments Work

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Treatments for Alopecia Areata do not all work in the same place. Tap one to see where it acts.

Pick a treatment
Skin basics
BARRIEREPIDERMISDERMISHAIRSIGNALSTOPS THE ATTACKSTOPS THE ATTACKBLOCKS THE SIGNALWAKES THE FOLLICLE UP

Immune cells are attacking the hair bulb. This switches that off in one patch.

The same target, for people who cannot have injections or have too many patches for them.

Blocks the immune message driving the attack, throughout the body. For widespread loss.

Does nothing about the attack. It supports regrowth once the attack settles.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Over-the-Counter Products

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Everything here you can buy without seeing anyone.

Sunscreen on a bare scalp
Sunscreen on a bare scalp
Always
Scalp skin that has been under hair all its life burns within minutes. Sunscreen, a hat or a scarf on any bare area is the one thing on this page that always applies, whatever else you are or are not doing. It does nothing for the hair loss itself — it prevents a painful burn and, on deeper skin tones, a dark mark that can last for months.
Wigs, toppers, brows and lashes
Wigs, toppers, brows and lashes
If you like
Not a lesser option, and not giving up. Wigs, toppers, scalp micropigmentation, brow pencils and false lashes let people carry on while treatment is tried, and many people use them for years alongside everything else. In the US many insurers cover a wig with a prescription, so it is worth asking your dermatologist to write one.
A plain white bottle with a gray applicator tip lying on its side, labeled MinoxidilDiagram of a hair follicle in cross-section, labeled to show that minoxidil keeps the follicle in its growing phase for longer.
Limited evidence
Minoxidil does not switch off the immune attack, so it will not clear a patch on its own here. What it does is support hair that is already coming back, which is why it is usually added to injections or a steroid rather than used by itself. It has to be kept up to keep any benefit.
Biotin and hair supplements
Biotin and hair supplements
Weak evidence
Biotin, collagen and hair-and-nail supplements are the first thing most people try. They do nothing for alopecia areata, because the problem is an immune attack rather than a shortage of a nutrient. Iron, vitamin D or thyroid problems are worth checking and correcting if a blood test shows one, but supplements taken on spec are not a treatment.
Rosemary oil and onion juice
Rosemary oil and onion juice
Weak evidence
These circulate constantly online, and neither has evidence worth acting on in alopecia areata. Because many single patches fill in on their own within a year, whatever someone was using at the time gets the credit. They are mostly harmless in themselves — the real cost is the months that pass while a spreading case goes untreated.

Prescriptions

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These need a prescription.

16:9 hero for Clobetasol Propionate. Never cropped: the tone strip and the corner logo depend on the full frame.
Clobetasol Propionate
Moderate evidence
A strong topical steroid used on the patch, often under a cover overnight to push it in. It is slower and less reliable than injections, and it is the usual choice for children and for anyone who does not want needles. Used for months on the same area it can thin the skin, so it is worked in cycles with breaks rather than applied indefinitely.
A white cream tube lying on its side on a white background, with a plain white label reading Anthralin and a blue swoosh beneath it.
Anthralin cream
Limited evidence
An old treatment applied for a short time each day and then washed off, deliberately causing a mild irritation that seems to distract the immune system from the follicle. It is used mainly in children and when steroids have not worked. It stains skin, hair and towels a brown-orange, and it needs patience over months.
An amber prescription bottle lying on its side on a white background with a plain white label reading Olumiant, and six small round white tablets spilled out in front of it.
Baricitinib (Olumiant)
Strong evidence
A JAK inhibitor tablet, approved for severe alopecia areata in adults, that blocks the immune signals attacking the follicle. In trials a substantial share of people with extensive loss regrew most of their scalp hair over several months to a year. It is not a cure — the loss usually returns after stopping — and it needs blood tests before and during treatment, with real risks around infection, blood clots and cholesterol to weigh up first.
An amber prescription bottle lying on its side on a white background with a plain white label reading Litfulo, and six small round white tablets spilled out in front of it.
Ritlecitinib (Litfulo)
Strong evidence
A second JAK inhibitor tablet for severe alopecia areata, approved from age 12, which makes it the option for teenagers as well as adults. The results, the monitoring and the trade-offs are broadly similar to baricitinib, and which one is chosen often comes down to age, other health conditions and what your insurance covers. A third, deuruxolitinib, is also available for adults.
16:9 hero for Prednisone. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Prednisone works in the skin
Limited evidence
A short course of steroid tablets is sometimes used to slow loss that is spreading quickly. It can work while it is being taken, and hair frequently falls out again once it stops. Because the side effects of long-term steroids are serious, it is a bridge to another treatment rather than a plan on its own.
16:9 hero for Methotrexate. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Methotrexate works in the skin
Limited evidence
An older immune-suppressing tablet used for extensive alopecia areata, sometimes with a low dose of steroid alongside. It has been overtaken by the JAK inhibitors for most people, and it stays useful where those are not available, not affordable or not suitable. It takes months to judge, needs regular blood tests, and must not be taken in pregnancy.

Procedures

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These are done in the office, usually over several visits.

Steroid Injections
Strong evidence
The fastest reliable option for a limited number of patches, and the usual first treatment in adults. Several small injections are placed across a patch, repeated every four to six weeks, with regrowth often visible in one to two months. They sting for a few seconds each, and numbing cream beforehand is fine to ask for. They can leave a lighter patch of skin or a small dent where the fat has thinned, which usually recovers over months and shows more on deeper skin tones. They treat the patches injected, not the tendency.
Contact Immunotherapy
Moderate evidence
A chemical is painted on the scalp to set off a deliberate mild allergic reaction, which appears to pull the immune system's attention away from the follicles. It is one of the better options for widespread loss where injections are not practical, and it is done in specialist centers. It means a mildly itchy, red, flaky scalp every week for months, and results take that long to appear.
16:9 hero for Excimer Laser. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Excimer Laser works in the skin
Limited evidence
Targeted ultraviolet light delivered to individual patches, usually twice a week for a few months. It is painless and can be useful for a small number of stubborn patches, including in children who cannot manage injections. The evidence is thin, regrowth often fades after treatment stops, and it asks for a lot of clinic visits.
16:9 hero for PRP for Hair Loss. Never cropped: the tone strip and the corner logo depend on the full frame.
Limited evidence
Your own blood is spun down and the platelet-rich part injected into the patch. Small studies in alopecia areata have shown some regrowth, but they are few and short, and there is no agreed recipe or schedule. It is not covered by insurance and courses are expensive, so it is a reasonable thing to try after the better-tested options rather than instead of them.
16:9 hero for Hair Transplant. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Hair Transplant works in the skin
Weak evidence
This is the wrong operation for alopecia areata, and it is worth knowing why before anyone offers it. The follicles here are alive and switched off rather than gone, so there is nothing to replace, and moved hairs land in skin where the same immune attack is still running and can be lost too. Transplants are for scarring hair loss and for pattern hair loss, where the follicle really has been destroyed.

When to See a Dermatologist

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A new patch of hair loss is worth booking early rather than waiting, because things that look like it are treated completely differently and are hard to judge from a photograph. Book if a patch appeared over days or weeks, if patches are multiplying or joining up, if you are losing eyebrows, eyelashes or beard hair, or if the scalp is itchy, sore, red, scaly or has broken hairs. Book too if a child has any patch of hair loss, if your nails have pitting or ridging, or if the loss is affecting your mood, sleep or work. At the visit we look through a lit magnifier for the broken hairs, black dots and fine regrowth that confirm it, pull gently at the edge to see whether it is active, and check thyroid function; a biopsy is rarely needed.

— Dr. Schwarz, Board Certified Dermatologist

Complications

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Sunburn on an unprotected scalp

Scalp skin that has been covered by hair all its life has no tan and no toughening, so it burns very fast — sometimes within twenty minutes. A burn there is painful, it can blister, and on deeper skin tones it often leaves a dark mark that outlasts the burn by months. Sunscreen, a hat or a scarf on any bare area prevents it entirely, and it is the easiest thing on this page to avoid.

Losing Eyebrows and Eyelashes

In some people the immune attack takes the brows and lashes as well as the scalp. Lashes keep dust, sweat and grit out of the eye, so losing them can leave the eyes gritty, watery and easily irritated, and wind and bright light feel worse. Sunglasses help day to day. This is also the loss people find hardest to cover, and it is a reasonable thing to bring up at the appointment rather than manage alone.

Anxiety and low mood

The weight of this is not a side issue. People field questions from strangers, cover up in photographs, and wake up not knowing what they will find on the pillow, and anxiety and low mood are well documented in alopecia areata. It is worth saying out loud at the appointment if it is affecting your sleep, your work or your mood. Support groups exist, and many insurers in the US cover a wig with a prescription.

Lookalikes

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Ringworm

Ringworm of the scalp is the mimic that matters most, especially in children, because it is catching and needs antifungal tablets rather than anything on this page. Both make round bald patches. The difference is the skin: ringworm is scaly, often itchy or tender, and leaves broken-off hairs and black dots in the patch, sometimes with a boggy swollen area. Alopecia areata skin is smooth, clear and comfortable. Any child with a bald patch should be checked for this first.

Telogen Effluvium

Both start suddenly and both frighten people, and telogen effluvium often follows an illness, an operation, childbirth or a hard few months. The difference is the shape of the loss. Telogen effluvium is shedding from everywhere at once — handfuls in the shower, a widening part, a thinner ponytail — with no bare patch anywhere. Alopecia areata takes complete round patches and leaves the hair between them untouched. Telogen effluvium almost always recovers on its own within six to nine months.

Male Pattern Hair Loss

The two get confused because both can leave the crown bare, and someone who has always assumed they were going bald may actually have a patch. Pattern hair loss is slow, taking years, and it follows a set shape: the temples recede and the crown thins, while the back and sides stay. Alopecia areata takes a complete round patch anywhere, over days or weeks, with a sharp edge and normal skin. The treatments have nothing in common, which is why telling them apart matters.

Myths

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  • "Stress caused this." Stress may trigger it in someone already susceptible. But plenty of episodes start in calm stretches, and the condition is driven by an inherited immune tendency, not by how well you handle your life. Relaxing more will not regrow the hair.
  • "It means something is badly wrong with my immune system." It means the immune system is mistargeting one tissue. Your immunity is not weak, and you are not at higher risk of infections. Other autoimmune conditions are somewhat more common, which is why thyroid function is checked, but most people have nothing else.
  • "It is contagious." It is not You cannot catch it or pass it on. Hair loss that is contagious is usually a fungal infection, a different diagnosis with a different treatment.
  • "Once the hair is gone it is gone." The follicle survives in alopecia areata, which is what separates it from scarring hair losses. Hair has regrown in people who had none for years, and that is why treatment is still offered late.
  • "Onion juice, garlic or rosemary oil will fix it." None has evidence worth acting on, and they are mostly harmless. The cost is the time lost while a spreading case goes untreated.
  • "It is the same as going bald." Pattern hair loss is slow hormonal thinning in a set pattern. This is an immune attack that produces sudden smooth patches, at any age and in either sex, and the treatments have nothing in common.
  • "There is nothing that can be done." Closer to true a decade ago than now. Injections work well for limited patches, and for severe disease the oral JAK inhibitors have changed the conversation. They are not right for everyone, but worth asking about.

Questions Patients Ask

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Will my hair grow back?

Often, but nobody can promise it. A single small patch fills in within a year in a large share of people, with or without treatment. Widespread loss is much less predictable. There is always a chance, because the follicle is switched off rather than destroyed, even after years.

Is this caused by stress?

Stress may trigger it in someone already predisposed. It is not the underlying cause, and calming your life down is not a treatment. Manage stress for its own sake, and do not blame yourself for the hair.

Is it contagious? Can my children catch it?

No. It cannot be passed by contact of any kind. There is an inherited tendency, so your children have a somewhat higher chance of developing it, but that is genetics rather than transmission.

Does this mean I will get other autoimmune diseases?

Not necessarily. Thyroid disease, vitiligo and a few others are more common, which is why thyroid function is checked once. Most people never develop another.

Do the steroid injections hurt, and how often do I need them?

They sting for a few seconds each, and there are usually several across a patch, so the appointment is uncomfortable rather than painful. They are typically repeated every four to six weeks while there is reason to continue. Numbing cream helps, and it is fine to ask for it.

Why did my hair come back white?

That is normal here. The pigment cells take longer to restart than the hair-making cells, so new growth comes through fine and pale before it thickens and regains color over the following months. It is a sign of recovery, not failure.

References

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