Hair Alopecia Telogen Effluvium: Definitive Guide

Telogen Effluvium: Definitive Guide

In this guide, we take a look at the symptoms, causes, diagnosis, and treatment of telogen effluvium. Large amounts of a person's hair may fall out, but it is often temporary, and the hair grows back.

Telogen effluvium is a kind of temporary baldness that occurs after anxiety, shock, or even a traumatic event. It occurs at the top of the scalp.

What is telogen effluvium?

Telogen effluvium is the name of a common cause of temporary hair loss due to excessive hair loss at rest or telogen after some shock to the system. The new hair continues to grow. Telogen hair is also known as stick hair due to the shape of the root.

It should be distinguished from anagen effluvium, in which hair loss is due to disruption of active or anagen hair growth by drugs, toxins, or inflammation (eg, alopecia areata). Anagen hair has a pointed or conical tip.

Who is affected by telogen effluvium?

Acute telogen effluvium can affect people of all ages and both sexes. Chronic telogen effluvium without a clear cause of precipitation tends to occur in otherwise healthy women 30 to 60 years of age.

What is the cause of telogen effluvium?

On the scalp of a normal healthy person, about 85% of the hair follicles are actively growing (anagen hair) and about 15% are at rest (telogen hair). Some hairs can also be in catagen. A hair follicle usually grows anagen hair for about 4 years, then rests for about 4 months. New anagen hair begins to grow under the resting telogen hair and expels it.

Therefore, it is normal to lose up to about 100 hairs a day in the comb, brush, sink or pillow, as a result of the normal scalp hair cycle.

If there is a shock to the system, up to 70% of anagen hairs can precipitate into the telogen, thus reversing the usual ratio. Typical triggers include:

  • Childbirth: hair loss in the postpartum. This may resolve after a few months or the transition to female pattern alopecia.
  • Physiological hair loss in newborns
  • Acute or chronic illness, especially if there is a fever
  • Surgery
  • Accident
  • Psychological stress
  • Weight loss, unusual diet, or nutritional deficiency (eg, iron deficiency)
  • Certain medications
  • Endocrine disorders (eg, hypothyroidism, hyperthyroidism)
  • Stop taking the birth control pill
  • Travel abroad involves jetlag
  • Skin diseases that affect the scalp (eg, erythroderma)
  • Excessive exposure to the sun.

What are the clinical characteristics of acute telogen effluvium?

Telogen effluvium is a non-scarring form of diffuse hair loss without clinical or histological evidence of inflammation and can affect up to 50% of scalp hair. 

The resting scalp club hairs remain firmly attached to the hair follicles at first. New hairs rising from the scalp push out the hairs from the resting club and the increased hair loss is noticeable 2 to 4 months after the trigger event.

So, paradoxically, with this type of hair loss, hair loss is a sign of hair regrowth.

When the new hair goes up the scalp and pushes the dead hair out, a thin strip of new hair is often evident along the forehead hairline.

At first, the fall of the hairs from the sticks is profuse and a general thinning of the hair of the scalp may become evident, but after several months a peak is reached and the fall of the hair begins to decrease, gradually decreasing until returning to the normality over 6-9 months in most cases.

As hair loss is reduced, the scalp thickens back to normal, but recovery may be incomplete in some cases.

Because nail and hair growth are under the same influences, a halt in hair growth is often reflected in the nails by a groove running through them that coincides with the moment of impact on the system - a Beau's line. The shock time can be estimated from the fact that it takes 5 months for a nail to grow from the back fold of the nail to the free edge. So if the groove of the nail is in the middle of the nail, the shock must have been two and a half months ago.

Chronic telogen effluvium

In some patients, hair loss continues to be intermittent or continuously greater than normal for long periods of time, sometimes for years. The hair cycle appears to be readjusted so that the anagen period is shortened.

Chronic telogen effluvium often occurs in women who actually still have fairly thick and moderately long hair - this is because they notice hair loss more than those with thinner or shorter hair. Telogen effluvium does not cause complete baldness, although it may unmask a genetic tendency to genetic baldness, that is, female pattern hair loss, or in men, male pattern hair loss.

The mechanism of chronic telogen effluvium is not well understood. Middle-aged women with a long fluctuating course of telogen effluvium, which produces generalized weight loss that lasts for many years, have normal hormonal studies.

How is telogen effluvium diagnosed?

Telogen effluvium is generally diagnosed by its clinical characteristics.

Thinning hair involves the entire scalp +/- loss of other body hair.

The examination shows diffuse thinning without focal areas of total alopecia and short hairs of normal thickness.

A gentle hair pull test reveals an increase in the number of hairs; most are telogens with a typical epithelial sac.

A trichogram can help confirm the diagnosis; more than 25% of the telogen hairs on a trichogram strongly suggest telogen effluvium.

Microscopic examination of light shows stick hair

A scalp biopsy is rarely needed; It is expected to show a normal terminal / hair ratio, an increase in the number of telogen follicles, and little or no inflammation and fibrosis.  

What is the differential diagnosis for telogen effluvium?

Other forms of hair loss to consider include:

  • Female pattern hair loss (look for a widened part and finer hair on the front and the apex of the scalp)
  • Male pattern hair loss (as a bi-temporal recession is sometimes observed in telogen effluvium).
  • Diffuse alopecia areata (look for associated immune phenomena, for example vitiligo). Scalp biopsy will show a peripheral lymphocytic infiltrate
  • Anagen effluvium (which tends to be more severe than telogen effluvium)
  • Hair shaft defects, including loose anagen hair syndrome.
  • Congenital atria
  • Congenital hypotrichosis

What is the treatment for telogen effluvium?

The telogen effluvium is self-correcting. Recommendations include:

  • Gentle manipulation of the hair, avoiding too vigorous styling, brushing and any type of massage on the scalp.
  • Treat any underlying disorders of the scalp or a certain hormonal problem, if any.
  • Ensure a nutritious diet, with plenty of protein, fruits and vegetables.  
  • Correct any abnormalities in thyroid function, or levels of iron, vitamin B12, and folic acid.
  • The psychological effects of hair loss should not be ignored.

What is the prognosis for telogen effluvium?

Regrowth usually occurs after removal of the trigger causing the telogen effluvium. However, repeated episodes of acute telogen effluvium can sometimes evolve into female pattern hair loss.

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Dr. Enrique Orozco
Dr. Enrique Orozco
General Director, Specialist in Trichology and Hair Transplantation Certified by ABHRS. Only ABHRS Certified with residence in Mexico.


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Dr. Enrique Orozco
General Director, Specialist in Trichology and Hair Transplantation Certified by ABHRS. Only ABHRS Certified with residence in Mexico.




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