Telogen effluvium

Telogen effluvium

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 Key points
*Condition is characterized by temporary hair loss due to shedding of resting, or telogen, hair after a shock to the system.
*Telogen hair has a bulb or club-shaped tip.
*System shock can be due to any number of causes and will result in hair reverting from anagen to telogen, so hair loss actually means the hair is regrowing.
*Nails may show a beau line — a groove across the nail — coinciding with the time of system shock.

Telogen effluvium is a condition characterized by temporary hair loss due to shedding of resting or telogen hair after a 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, where the hair sheds due to interruption of active or anagen hair growth by drugs, toxins or inflammation (alopecia). Anagen hair has a pointed or tapered tip.

In a normal healthy scalp, about 85% of the hair are active growing (anagen) and 15% are resting (telogen). A hair follicle usually grows anagen for 4 years or so, then rests for 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 about 100 hairs a day as a result of the normal scalp 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 causes include illness (especially with fever), surgical operation, accident, childbirth, nervous shock, weight loss or unusual diet, certain medications, discontinuing the contraceptive pill, overseas travel resulting in jetlag or 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 scalp hair may occur 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, which 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.

In some patients, hair shedding continues to be greater than normal for long periods of time, sometimes for years. Chronic Telogen effluvium often presents in women that actually continue to have 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 gender-pattern baldness.

Differential Diagnosis (Other conditions with similar appearance)
Alopecia areata
Androgenetic alopecia

Key Points
*Diagnosis is determined typically through clinic inspection of the hairs to determine if they are telogen.
*A scalp biopsy can also be useful when hairs are difficult to collect.

Diagnosis of telogen effluvium is usually determined through clinical inspection by collecting the hairs to determine if they are telogen — containing a tip that is bulb or club-shaped. Laboratory testing is usually unnecessary, but a scalp biopsy can be performed if a satisfactory sampling of hairs cannot be collected, and also to determine if there are other root causes.

Key Points
*Telogen effluvium is self-correcting, so not treatment is typically given.
*Careful hair maintenance and a nutritious diet help promote hair health.

Telogen effluvium is self-correcting, and is not really influenced by any treatment that can be given. However, gentle handling of the hair, avoiding vigorous combing, brushing and any type of scalp massage are important. A nutritious diet, full of protein, fruit, and vegetable is also important. A doctor may check thyroid function, iron levels, vitamin B12 and folic acid levels, as any deficiencies may slow hair growth.

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