Circular hair loss (alopecia areata)

Overview: What is circular hair loss?

The first signs of circular hair loss (alopecia areata) usually appear unexpectedly: All of a sudden, round, hairless patches appear where hair was previously visible.
In most sufferers, only the hair on the head is affected.
In rare cases, however, eyebrows, eyelashes, beard or other hairy parts of the body can also be affected by hair loss.
In most cases, only individual hairless “islands” form with circular hair loss.
However, there are also less common subtypes with a different appearance:

• In alopecia areata totalis , the hairless areas merge into one another until the entire head is bald.
• In alopecia areata universalis, the entire body is affected by hair loss.
• In ophiasis-type alopecia areata, the hair on the nape or back of the head disappears.

The cause of circular hair loss has not been conclusively clarified.
They assume that the body’s own immune system plays a decisive role.
It presumably directs its defenses not against pathogens, but against its own body.
More precisely: against the hair root (follicle).
This is where inflammation occurs, which disrupts hair growth and ultimately leads to hair loss.

Circular hair loss – frequency and age

Circular hair loss (alopecia areata) affects men and women equally.
All age groups can be affected, including children.
However, it is young adults who suffer from circular hair loss more often than average.
Alopecia areata is not a rare disease: around 1 – 2 percent of the population receive this diagnosis in the course of their lives.
For the 8.7 million Swiss, this means that around 85,000 to 175,000 of them have already experienced circular hair loss, currently suffer from it or will suffer from it in the future.

Circular hair loss: What are the causes?

Even though circular hair loss (alopecia areata) is rarely inherited directly, hereditary factors appear to play a role.
Various genes have been identified that are or could be involved in the development of circular hair loss.
For those affected, this means

• In first-degree relatives, the inheritance risk is between 6 and 8 percent.
• There is no increased risk of circular hair loss in second-degree relatives: At around 1 to 2 percent, it corresponds to the risk of the population as a whole.

Circular hair loss is probably an autoimmune disease.
This means that the immune system turns against its own body.
Apparently, certain white blood cells (T lymphocytes) attack the roots of the hair.
Although they do not destroy them, they trigger inflammatory reactions that lead to alopecia (hair loss).
It is certain that circular hair loss is not caused by malnutrition or hormones.
Environmental influences do not appear to play a role either: the disease was already described in ancient times.

Symptoms: How does circular hair loss manifest itself?

Circular hair loss on the scalp usually results in a hairless patch with a diameter of 1-2 centimeters.
This is often followed by further bald patches.
The affected patches are not always exactly circular or round, but are clearly demarcated from their hairy surroundings.
Alopecia areata does not cause pain, but may be accompanied by slight itching.
In the majority of those affected, there are no more than two hairless patches.
However, alopecia can also spread further – to the point of complete loss of head hair or even all body hair.

Prognosis: How does circular hair loss progress?

The course of circular hair loss (alopecia areata) cannot be predicted.
Some sufferers find that the alopecia disappears on its own after six to twelve months and never returns.
In other patients, the lost hair also grows back, but at some point the circular hair loss reappears.
And still others experience no improvement at all, not even temporarily.
Around 20-30% of those affected suffer from permanent hair loss.
Even a chronic course of circular hair loss has no effect on life expectancy.
However, alopecia areata can certainly have a negative impact on mental well-being.

Self-help groups

Talking to people with the same condition can be a great support when coping with an illness. Advice on finding a suitable self-help group is available from Selbsthilfe Zürich. Self-Help Zurich and the University Hospital Zurich are cooperation partners in the national project “Health literacy thanks to self-help-friendly hospitals”.

Therapy: How is circular hair loss treated?

As the mechanisms behind circular hair loss are not exactly known, it cannot be cured.
Nevertheless, various drugs are available to treat the symptoms.
Their effect usually wears off as soon as they are discontinued.
Among others, the following drugs are available for the treatment of alopecia areata:

• Minoxidil is an active ingredient that stimulates the hair roots (follicles), which is intended to promote hair growth.
• Cortisone is intended to stop inflammatory reactions at the hair roots.
• Diphenylcyclopropenone (DCP) produces an allergic reaction on the scalp.
  It is designed to attract the immune system to itself so that its activity is bound and no longer directed against the follicles.
• Baricitinib is a novel active ingredient that influences the immune system and has anti-inflammatory properties.
  Baricitinib has been approved for the treatment of alopecia areata in the USA since 2022.