Alopecia areata

What is alopecia areata?

Alopecia areata (pronounced a·luh·pee·shee·uh a·ree·uh·tuh) is an autoimmune disease where your body’s defence system mistakenly attacks your hair follicles, leading to hair loss.^[1] Hair follicles are like little pockets in your skin where hair grows from.

People with alopecia areata are usually healthy and don’t have any other symptoms. It usually starts with unexpected hair loss in round or oval patches on the scalp, but it can also affect other areas like the beard, eyebrows and eyelashes.

The course of alopecia areata can vary, with periods of hair loss and regrowth. Some people experience periods of hair loss at different times in their lives, while others may only have one episode.

What types of alopecia areata are there?

There are different types of alopecia areata ^[2] (and all of them have catchy names):

• Patchy alopecia areata, which involves the loss of hair in one or multiple separate patches.
• Alopecia totalis, where there is a complete or near-complete loss of hair on the scalp.
• Alopecia universalis, here there is a total or near-total loss of hair on all parts of the body.
• Alopecia incognita (also known as diffuse alopecia areata), characterised by diffuse hair loss, yellow dots, and short, tiny regrowing hairs, but without any signs on the nails.
• Ophiasis alopecia, when hair loss is more evident around the temples and at the back of your head.
• Sisaipho alopecia, which involves extensive hair loss except for the area around the edges of the scalp.
• Marie Antoinette syndrome, which refers to a sudden episode where hair turns grey “overnight” (in case you were wondering, it comes from the story of Marie Antoinette, whose hair is said to have turned grey the night before she was guillotined during the French Revolution).

Who gets alopecia areata?

Alopecia areata can affect anyone. It doesn’t matter if you’re a man or a woman, and it can happen to people of any race or ethnicity. The condition can start at any age, but it’s most common in teenagers, people in their twenties, or those in their thirties. When children under the age of 10 experience it, the hair loss tends to be more widespread and may worsen over time.

While we don’t know exactly what causes alopecia areata, scientists believe that genetics may play a role. So if someone in your immediate family has it, you may have a higher chance of developing it too. But for many people, there’s no family history of the condition.

People with other autoimmune diseases like psoriasis, thyroid problems or vitiligo are also more prone to developing alopecia areata. And allergies like hay fever or psychological problems like stress can trigger alopecia areata as well.^[3]

Sometimes, alopecia areata can happen after childbirth. This is also known as postpartum alopecia and is due to hormone imbalances caused by pregnancy. This condition is usually only temporary.

How common is alopecia areata?

Alopecia areata is a common type of hair loss. It’s actually the second most common type of non-scarring hair loss (when hair falls out but doesn’t leave permanent scars), right after male and female pattern baldness. It’s estimated that almost 2% of the general population will experience alopecia areata at some point in their lives.^[2]

What causes alopecia areata?

We don’t yet know what causes your immune system to attack your hair follicles, but scientists believe that both genetic and environmental triggers may play a role.

Stress from emotions and daily life can contribute to the onset or worsening of alopecia areata.^[3] Smoking seems to make you more likely to get it too. And there’s a possibility (though no solid proof) that other triggers like drinking alcohol, being overweight, having an imbalanced diet and not getting enough sleep might also play a role in causing it.^[4]

Because low vitamin D levels can occasionally cause other autoimmune diseases like multiple sclerosis or rheumatoid arthritis, scientists looked at this in people with alopecia areata as well. However, they couldn’t draw any conclusions, because they found that some people had low vitamin D levels, but others didn’t. So more research is needed to understand its role in alopecia areata.^[2]

What are the symptoms of alopecia areata?

Alopecia areata can affect both hair and nails, though the latter is less common. But other than that, people with alopecia are usually healthy and have no other symptoms.

In the early stages of the condition, hair loss happens in small, round patches on the scalp. Hair in other body parts like beard, eyebrows or eyelashes may also be affected. Another sign of alopecia areata is usually the appearance of hairs resembling exclamation marks (they’re thicker at the tip and slimmer at the base of the hair). Sometimes you can feel a tingling, burning or itching sensation on the skin right before the hair falls out.

After that, the hair may grow back on its own. It might be grey or white at first and regain its colour over time. Sometimes, hair regrows in the first bare patch while new ones start forming. And these small patches may grow to form larger ones.

In rare cases, called alopecia totalis, hair falls off the entire scalp. And in even rarer cases, hair loss can happen across all your body, called alopecia universalis.

Nail changes can happen in some people and they appear mostly as off-white ridges or pits (similar to the dimples on a thimble) on the surface of the nails. These are more likely to happen to those who experience more extensive hair loss.^[5]

Is alopecia areata associated with other conditions?

If you suffer from alopecia areata you might have a higher risk of developing other autoimmune disorders, including vitiligo, thyroid disease, psoriasis, lupus, irritable bowel syndrome and rheumatoid arthritis. Likewise, if you suffer from these conditions, you might have an increased risk of developing alopecia areata. Alopecia has also been linked to diabetes, anxiety and depression.^[1]

The risk of certain types of cancer, like thyroid and bladder, was also found to be higher in patients with alopecia areata than in the general population. Doctors didn’t find any connection between alopecia areata and skin cancer though.^[6]