Telogen effluvium is the name for temporary hair loss due to shedding of resting or telogen hair after some shock to the system. New hair continues to grow. Telogen hair has a bulb or club-shaped tip.
It should be distinguished from anagen effluvium, in which the hair shedding is due to interruption of active or anagen hair growth by drugs, toxins or inflammation (e.g. alopecia areata). Anagen hair has a pointed or tapered tip.
What is the cause of telogen effluvium?
In a normal healthy person's scalp about 85% of the hair follicles are actively growing hair (anagen hair) and 15% are resting hair (telogen hair). A hair follicle usually grows anagen hair for 4 years or so, then rests for about 4 months. The resting or telogen hair has a club or bulb at the tip. A new anagen hair begins to grow under the resting telogen hair and pushes it out.
Thus, it is normal to lose up to about 100 hairs a day on one's comb, brush, in the basin or on the pillow, as a result of the normal scalp hair cycle.
If there is some shock to the system, as many as 70% of the anagen hairs can be precipitated into telogen, thus reversing the usual ratio. Typical precipitants include:
- Illness, especially if there is fever
- Surgical operation
- Nervous shock
- Weight loss or unusual diet
- Certain medications
- Discontinuing the contraceptive pill
- Overseas travel resulting in jetlag
- Excessive sun exposure
The resting scalp hairs, now in the form of club hairs, remain firmly attached to the hair follicles at first. It is only about 2 months after the shock that the new hairs coming up through the scalp push out the "dead" club hairs and increased hair fall is noticed.
Thus, paradoxically, with this type of hair loss, hair fall is a sign of hair regrowth. As the new hair first comes up through the scalp and pushes out the dead hair a fine fringe of new hair is often evident along the forehead hairline. At first the fall of club hairs is profuse and a general thinning of the scalp hair may become evident but after several months a peak is reached and hair fall begins to lessen, gradually tapering back to normal over 6-9 months. As the hair fall tapers off the scalp thickens back up to normal, but recovery may be incomplete in some cases.
Because nail and hair growth are under the same influences, an arrest in hair growth is often mirrored in the nails by a groove across them coinciding with the time of the shock to the system. This is called a Beau's line. The time of the shock can be estimated from the fact that a finger nail takes 5 months to grow from the posterior nail fold to the free edge. So if the groove in the nail is half way down the nail then the shock must have been 2 1/2 months ago.
Chronic telogen effluvium
In some patients, hair shedding continues to be intermittently or continuously greater than normal for long periods of time, sometimes for years. The hair cycle appears to be reset so that the anagen period is shortened.
Chronic telogen effluvium often presents in women that actually continue to have quite thick and moderately long hair – this is because they notice the shed hair more than those with finer or shorter hair. Telogen effluvium does not cause complete baldness, although it may unmask a genetic tendency to genetic balding i.e. female pattern hair loss , or in men, male pattern hair loss.
What is the treatment for telogen effluvium?
Telogen effluvium is self-correcting. It is really not influenced by any treatment that can be given. However, gentle handling of the hair, avoiding over-vigorous combing, brushing and any type of scalp massage are important.
You should also ensure a nutritious diet, with plenty of protein, fruit and vegetables.
The doctor may check your thyroid function, and levels of iron, vitamin B12 and folic acid, as any deficiency in these can slow hair growth.