What is telogen effluvium?
Hairs grow in follicles in the skin, each follicle repeatedly producing a hair in a cycle of three steps: growing, transition, and rest. At the end of the resting phase a hair falls out, which is normal. In telogen effluvium, an unusually large number of hairs enter the resting phase at the same time, so for a while more hairs than normal fall out. It is temporary hair loss caused by a disturbance of the hair growth cycle.
What causes it?
There are two forms: acute (shorter than 6 months) and chronic (longer than 6 months).
Acute telogen effluvium can follow childbirth (postpartum), a serious illness or a period with high fever, an operation under anaesthetic, major blood loss, or rapid weight loss or a strict “crash” diet. The extra hair loss usually only becomes clear 2 to 5 months later, and sometimes no clear cause is found.
Chronic telogen effluvium can be linked to thyroid problems, anaemia from iron deficiency, certain medicines (for example some acne treatments, blood thinners or beta-blockers), or too much of certain supplements (for example vitamin A). Here too a clear cause is not always found.
What do you notice?
You lose more hairs than normal, especially when combing or washing. There are usually no real bald patches, but the hair can become thinner — often the people around you only notice once a lot of hair has already fallen out.
What is the course?
In most people the extra hair loss stops on its own, especially in the acute form, after which the hair grows back. This is slow, as hair grows on average about 1 cm per month. Importantly, even after the hair loss stops it can take months before the hair looks “full” again. The good news is that telogen effluvium leaves no scars on the scalp — the follicles stay intact, so the hair can usually return.
How does the doctor make the diagnosis?
The doctor asks about the start of the hair loss and possible events in the months before (such as fever, an operation, childbirth, a diet or new medicines). A hair-pull test is done, gently pulling on a small tuft of hair to see whether relatively many hairs come loose; sometimes the shed hairs are examined with a magnifier or microscope. For long-lasting complaints, blood tests may be needed (for example iron, blood count and thyroid).
How is it treated?
Explanation and watchful waiting is usually the main step: in acute telogen effluvium the hair usually recovers on its own, and there is no proven treatment that really speeds recovery. Where there is a cause, it is addressed — iron for iron deficiency, thyroid treatment for thyroid problems, or reviewing a medicine with the doctor (do not stop it yourself). If hair loss lasts longer than 6 months, the doctor can check whether another form of hair loss (such as hereditary hair loss) is also playing a role, and a treatment such as minoxidil may then be discussed, though this is not needed or suitable for everyone. If it bothers you greatly, a wig or hairpiece can give temporary relief.
What can you do yourself?
Be gentle with your hair (do not blow-dry too hot, do not rub hard with a towel); avoid tight hairstyles that put tension on the hair; eat varied and sufficiently, using supplements only if the doctor advises; and try to reduce stress — stress is not always the cause, but rest can help recovery.
When to see a doctor
See a doctor if hair loss lasts longer than 6 months, if you get round/oval bald patches or loss of eyebrows/eyelashes, if the scalp is red, scaly, painful or crusted, if you have other complaints (such as extreme fatigue, unexplained weight loss or heavy bleeding), or if you think a medicine is the cause.