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

The course of alopecia areata varies from person to person. Some have bouts of hair loss throughout their lives, while others only have one episode. Recovery is unpredictable too, with hair regrowing fully in some people but not others.

There is no cure for alopecia areata, but there are treatments that help hair grow back more quickly. There are also resources to help people cope with hair loss.

Alopecia areata is a common disorder that causes hair loss. "Alopecia" is a Latin term that means baldness, and "areata" refers to the patchy nature of the hair loss that is typically seen with this condition.

In most people with alopecia areata, hair falls out in small, round patches, leaving coin-sized areas of bare skin. This patchy hair loss occurs most often on the scalp but can affect other parts of the body as well. Uncommonly, the hair loss involves the entire scalp (in which case the condition is known as alopecia totalis) or the whole body (alopecia universalis). Other rare forms of alopecia areata, which have different patterns of hair loss, have also been reported.

Alopecia areata affects people of all ages, although it most commonly appears in adolescence or early adulthood. Hair loss occurs over a period of weeks. The hair usually grows back after several months, although it may fall out again. In some cases, unpredictable cycles of hair loss followed by regrowth can last for years. In addition to hair loss, some affected individuals have fingernail and toenail abnormalities, such as pits on the surface of the nails.

The hair loss associated with alopecia areata is not painful or disabling. However, it causes changes in a person's appearance that can profoundly affect quality of life and self-esteem. In some people, the condition can lead to depression, anxiety, and other emotional or psychological issues.

Alopecia areata affects 1 in every 500 to 1,000 people in the United States. It is one of many recognized forms of alopecia; alopecia areata is the second most common form after androgenetic alopecia (male-pattern baldness in men and female-pattern baldness in women). Alopecia areata affects men and women equally, and it can occur in people of any ethnic background.

There are three main types of alopecia areata:

• Patchy alopecia areata. In this type, which is the most common, hair loss happens in one or more coin-sized patches on the scalp or other parts of the body.
• Alopecia totalis. People with this type lose all or nearly all of the hair on their scalp.
• Alopecia universalis. In this type, which is rare, there is a complete or nearly complete loss of hair on the scalp, face, and rest of the body.

Anyone can have alopecia areata. Men and women get it equally, and it affects all racial and ethnic groups. The onset can be at any age, but most people get it in their teens, twenties, or thirties. When it occurs in children younger than age 10, it tends to be more extensive and progressive.

If you have a close family member with the disease, you may have a higher risk of getting it, but for many people, there is no family history. Scientists have linked a number of genes to the disease, which suggests that genetics play a role in alopecia areata. Many of the genes they have found are important for the functioning of the immune system.

People with certain autoimmune diseases, such as psoriasis, thyroid disease, or vitiligo, are more likely to get alopecia areata, as are those with allergic conditions such as hay fever.

It is possible that emotional stress or an illness can bring on alopecia areata in people who are at risk, but in most cases, there is no obvious trigger.

The causes of alopecia areata are complex and not well understood. A combination of factors likely underlies the disorder, including changes in many genes that function in the hair and skin and in the immune system.

Alopecia areata is one of a large group of immune system diseases classified as autoimmune disorders. Normally, the immune system protects the body from foreign invaders, such as bacteria and viruses, by recognizing and attacking these invaders and clearing them from the body. In autoimmune disorders, the immune system malfunctions and attacks the body's own tissues instead. For reasons that are unclear, in alopecia areata the immune system targets hair follicles, stopping hair growth. However, the condition does not permanently damage the follicles, which is why hair may later regrow.

Many of the genes that have been associated with alopecia areata participate in the body's immune response. These include several genes belonging to a gene family called the human leukocyte antigen (HLA) complex. The HLA complex helps the immune system distinguish the body's own proteins from proteins made by foreign invaders. Each HLA gene has many different variations, allowing each person's immune system to react to a wide range of foreign proteins. Certain variations in HLA genes likely contribute to the inappropriate immune response targeting hair follicles that leads to alopecia areata. Immune system genes outside the HLA complex, such as several genes involved in inflammation, have also been associated with alopecia areata.

Some of the genetic variations associated with alopecia areata have been identified in people with other autoimmune disorders, which suggests that this group of diseases may share some genetic risk factors. People with alopecia areata have an increased risk of developing other autoimmune disorders, including vitiligo, systemic lupus erythematosus, atopic dermatitis, allergic asthma, and autoimmune thyroid diseases (such as Hashimoto's disease and Graves' disease). Similarly, people with those autoimmune disorders have an increased risk of developing alopecia areata.

In many cases, it is unknown what triggers hair loss in people with alopecia areata. It is possible that environmental factors, such as emotional stress, physical injury, or illness, provoke an abnormal immune response in people who are at risk. However, in most affected people, the onset of hair loss has no clear explanation.

Alopecia areata primarily affects hair, but in some cases, there are nail changes as well. People with the disease are usually healthy and have no other symptoms.

Hair Changes

Alopecia areata typically begins with sudden loss of round or oval patches of hair on the scalp, but any part of the body may be affected, such as the beard area in men, or the eyebrows or eyelashes. Around the edges of the patch, there are often short broken hairs or “exclamation point” hairs that are narrower at their base than their tip. There is usually no sign of a rash, redness, or scarring on the bare patches. Some people say they feel tingling, burning, or itching on patches of skin right before the hair falls out.

When a bare patch develops, it is hard to predict what will happen next. The possibilities include:

• The hair regrows within a few months. It may look white or gray at first but may regain its natural color over time.
• Additional bare patches develop. Sometimes hair regrows in the first patch while new bare patches are forming.
• Small patches join to form larger ones. In rare cases, hair is eventually lost from the entire scalp, called alopecia totalis.
• There is a progression to complete loss of body hair, a type of the disease called alopecia universalis. This is rare.

In most cases, the hair regrows, but there may be subsequent episodes of hair loss.

The hair tends to regrow on its own more fully in people with:

• Less extensive hair loss.
• Later age of onset.
• No nail changes.
• No family history of the disease.

Nail Changes

Nail changes such as ridges and pits occur in some people, especially those who have more extensive hair loss.

Doctors usually diagnose alopecia areata by:

• Examining the areas where the hair has been lost and looking at your nails.
• Examining your hair and hair follicle openings using a handheld magnifying device.
• Asking about your medical and family history.

Other health conditions can cause hair to fall out in the same pattern as alopecia areata. To determine if another condition is causing the hair loss, your doctor may order blood tests or a skin biopsy.

For many people, hair grows back without any type of treatment. For people with milder cases, no treatment may be needed. Some people with severe cases opt to forego treatment as well, and may instead consider products that conceal hair loss, such as hairpieces or wigs.

If you choose to seek treatment, your doctor will take into account your age and the extent of hair loss when making a treatment plan. While there are no drugs that have been approved by the U.S. Food and Drug Administration for alopecia areata, medications that have been approved for other conditions may be used to treat it. These include corticosteroids, immunosuppressants, and other medications that stimulate hair regrowth. The main goal of therapy is to stop the immune system attack on hair follicles and to stimulate the regrowth of hair.

Who Treats Alopecia Areata?

Alopecia areata is treated by:

• Dermatologists, who specialize in conditions of the skin, hair, and nails.

Other specialists who may be involved in your care include:

• Mental health professionals, who can help with the psychosocial challenges caused by having a medical condition.
• Primary care doctors, such as family physicians or internal medicine specialists, who coordinate care between the different health providers and treat other problems as they arise.

Alopecia areata does not cause physical disability, but it may affect your sense of well-being. There are many things you can do to cope with the effects of this disease, including:

Get support.

• Learn as much as you can about the disease, and talk with others who are dealing with it. Having a support network can help you deal with difficult times.
• Visit a mental health professional if emotional problems arise. People with alopecia areata may have higher levels of stress, and depression and anxiety are more common in people with the disease.

Protect bare skin and stay comfortable.

• Use sunscreens for any bare areas.
• Wear wigs, hairpieces, hats, or scarves to protect your scalp from the sun and to keep the head warm.
• Wear eyeglasses or sunglasses to protect your eyes from sun and dust if you have lost hair from your eyebrows or eyelashes.

Consider cosmetic solutions.

• Wear a wig, hairpiece, or bandana to cover up hair loss. Alternatively, some people choose to shave their heads to mask patchy hair loss.
• Use fake eyelashes or apply stick-on eyebrows if you lose hair from your eyelashes or eyebrows. Makeup or tattoos can also disguise loss of eyebrow hair.

People with alopecia areata have a higher risk of certain diseases such as thyroid disease, atopic dermatitis, or other autoimmune diseases, so it is important to visit your primary care doctor regularly. The sooner these diseases are diagnosed, the easier they are to control.

Alopecia areata is a difficult disease to cope with, but there are ways for people to feel better.

The condition causes your hair to fall out. Some people lose all of their hair, but most people lose hair in small, round patches.

While it isn't painful, the condition can cause serious confidence and self-image issues.

Your genes and the environment work together to determine if you get alopecia areata.

While there isn't a cure, researchers like Angela Christiano, Ph.D., and others supported by NIH are working to improve medicines to help hair grow back. Talk to your doctor about which medicines could help you.

There are also ways to cope with the mental hurdles that come with alopecia areata. If you or someone you love has alopecia areata, you can: