Postpartum hair loss and shedding after illness or dieting: telogen effluvium

The hair cycle

Each hair goes through a cycle: a long growth phase, then a resting phase of a few months, at the end of which it falls out and makes way for a new hair. At any given time, about nine hairs in ten are growing, and only 5 to 10% are resting.

A shock to the body suddenly pushes many hairs into the resting phase at once. They fall out together, usually two to five months later, often at around three months: this is telogen effluvium. The delay explains why people rarely link it to the event that triggered it.

Postpartum hair loss

During pregnancy, hair cycles become synchronised. After the birth, many hairs enter the resting phase together, then fall out at the same time.

In a Japanese survey of 331 mothers, shedding started on average around three months after delivery, peaked around five months and stopped around eight months. This form only very rarely becomes chronic, and recovery is usually complete.

Other triggers

The possible causes are many. Among the most familiar:

• a high fever or a severe infection;
• surgery or a severe chronic illness;
• a very strict diet or poor nutrition;
• major physical or emotional stress;
• stopping a contraceptive pill;
• some medicines, including retinoids, anticoagulants, beta blockers, anti-epileptic drugs and antithyroid drugs.

If a medicine is involved, never stop it on your own: discuss it first with the doctor who prescribed it.

The reassuring part

In telogen effluvium, the follicle, the small structure that makes the hair, is not damaged. Once the cause has passed, shedding usually settles within a few months and the hair grows back. Because hair grows slowly, it still takes time to recover the previous volume: the number of hairs comes back well before their length. A feeling of pain or tingling in the scalp sometimes accompanies this shedding: it is part of the picture of telogen effluvium.

This shedding is worrying, and understandably so. Seeing your hair on the pillow or in the shower, sometimes while caring for a newborn, is not trivial. Talking about it already helps.

When to see a doctor

A medical opinion is useful in three situations:

• the shedding lasts more than six months: this is called the chronic form, and its cause should be looked for;
• it comes with redness, scaling or bald patches, which point to other scalp conditions;
• the hair is thinning rather than falling out, or the parting is widening: androgenetic alopecia, which is hormonal and hereditary, may be showing at the same time.

The consultation starts with the history of your hair loss and an examination of the scalp, with reference photographs. The dermatoscope, an illuminated magnifier, helps to tell telogen effluvium apart from androgenetic alopecia. A targeted blood test looks, depending on the situation, for iron deficiency or a thyroid disorder.

What does not help, or not now

Supplements rich in biotin are widely sold for hair loss. No study has demonstrated an effect in people who are not deficient, and deficiency is rare. At high doses, biotin can also distort some blood tests, particularly hormone tests: always mention it before a blood test.

Minoxidil lotions treat androgenetic alopecia. Their product information states that they are not indicated when hair loss follows childbirth, and that they must not be used while breastfeeding. Nor do I offer PRP in this situation: the shedding resolves on its own.

Finally, shedding that stops by itself often makes the last product tried look effective. This is one more reason to compare photographs rather than impressions.