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Alopecia Areata

  • An autoimmune disease that causes hair loss
  • Hair is often lost in circular patches, ranging from small to large areas
  • Treatments include steroid injections, topical and oral medications
  • Involves dermatology, medical dermatology, pediatric dermatology


“Alopecia” means hair loss, and that includes everything from common male-pattern baldness to chemotherapy-induced hairlessness to patchy bald spots appearing out of the blue to the complete loss of all scalp, facial and body hair.

When patients come to Yale Medicine seeking treatment for alopecia areata, they have a form of hair loss that is an autoimmune disease. Yale Medicine doctors are at the forefront of research on alopecia areata and see patients who travel from around the world for treatment. It is a condition affects about two out of 100 people and causes symptoms that may wax and wane over a patient’s lifetime.

In patients with alopecia areata, hair follicles release a chemical message that causes the immune system to attack them. This causes the hairs in those follicles to fall out. As long as the immune system is fighting the follicles, new hair will not grow.

What are the risk factors for alopecia areata?

Alopecia areata appears to be a genetic condition with multiple genes playing a role. Environmental influences such as exposure to a virus or chemicals might cause a predisposition to this condition. “Alopecia areata affects men and women similarly and has no known predilection for any ethnic group,” says Brett King, MD, a Yale Medicine dermatologist. It typically develops before age 20, but it can also arise later in life.

What are the symptoms of alopecia areata?

People with alopecia areata most commonly lose hair on their heads in circular patches. Some patches are about the size of a coin and can be easily covered up, but more severe cases may affect larger portions of the scalp or even the entire body.

The following terms describe the extent of the hair loss.

  • Alopecia areata refers to patchy hair loss.
  • Alopecia totalis describes the total loss of hair on the head.
  • Alopecia universalis is the name for the complete loss of hair on the head, face and body.

How is alopecia areata diagnosed?

Typically, a doctor can diagnose alopecia areata by examining the hair loss and asking about the patient’s history. In some cases, a biopsy can confirm the diagnosis. “We’re looking for a pattern of immune cells that nest around the hair follicle in the skin,” says Dr. King. “It’s a signature for the disease.”

What are the treatment options for alopecia areata?

Many mild cases of alopecia areata will resolve without treatment, although the condition often reappears over a patient's lifetime.

Traditional treatments for alopecia areata include steroid injections to the areas where the hair has been shed. The steroids suppress the immune system cells, so hair can regrow.

Another approach is the topical application of an irritant such as squaric acid, which results in a rash similar to poison ivy. The resulting inflammation seems to distort the immune system’s attack on the hair follicles, though the treatment is unpleasant for the patient. “Historically, when there was not a whole lot else available, if you were dismayed enough by your condition, you suffered through it,” says Dr. King. 

For more severe cases of alopecia areata, Dr. King recently pioneered a breakthrough treatment. He’d been following research on Janus kinase inhibitors, a class of medications that disrupt messages to the immune system. One of those medications, Xeljanz (tofacitinib), is approved for rheumatoid arthritis and is in clinical trials for psoriasis. It had also been shown to reverse alopecia areata in mice, presumably by blocking the message from the hair follicle to the immune system.

Dr. King prescribed it to a patient who had psoriasis and alopecia areata. “Eight months later, he had a headful of hair and eyelashes and eyebrows for the first time in years, which was the first demonstration of such a result,” Dr. King says. “Now, that result has been repeated many times.” 

People with severe alopecia areata have come to Yale Medicine from all over the world, and Dr. King has prescribed the medication to hundreds of them. His research shows that about two-thirds of patients respond well to treatment and regrow hair. 

What makes Yale Medicine’s approach to treating alopecia areata unique?

Yale Medicine dermatologists will often prescribe Xeljanz (tofacitinib) for patients whose alopecia areata is severe, while doctors at most other institutions have not yet adopted this approach. 

“It’s easy to argue that this class of medicines is going to be the treatment of choice in years to come,” says Dr. King.