Telogen Effluvium

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Continuing Education Activity

Telogen effluvium is a form of nonscarring alopecia characterized by diffuse, often acute hair shedding. Telogen effluvium is a reactive process, triggered by metabolic stress, hormonal changes, or medications. Common triggering events are acute febrile illness, severe infection, major surgery, severe trauma, postpartum hormonal changes, particularly a decrease in estrogen, hypothyroidism, discontinuing estrogen-containing medication, crash dieting, low protein intake, heavy metal ingestion, and iron deficiency. Many medications have been linked to telogen effluvium, but the most common are beta-blockers, retinoids, including excess vitamin A, anticoagulants, propylthiouracil, carbamazepine, and immunizations. This activity reviews telogen effluvium and highlights the role of the interprofessional team in the recognition and management of patients affected by it.


  • Describe the causes of telogen effluvium.
  • Identify the testing that should be done if telogen effluvium is suspected.
  • Outline the treatment strategies for a patient with telogen effluvium.
  • Review the importance of enhancing care coordination among the interprofessional team to ensure proper evaluation and management of telogen effluvium.


Telogen effluvium is a form of nonscarring alopecia characterized by diffuse, often acute hair shedding.[1][2][3][4][5] Another form that is chronic with a more insidious onset also exists. Telogen effluvium is excessive shedding of resting or telogen hair after some metabolic stress, hormonal changes, or medication. Telogen hair is also known as club hair due to the shape of the root. In a normal healthy person's scalp, about 85% are anagen hair and 15% are telogen hair. Anagen hair are actively growing hair while telogen hair are resting hair. A few hairs may also be in catagen. A hair follicle usually grows anagen hair for almost four years, then rests for about four months. A new anagen hair begins to grow under the resting telogen hair and pushes it out. If there is some kind of stress to the body it can cause 70% of anagen hair to precipitate into the telogen phase thus causing hair loss.


Telogen effluvium is a reactive process, triggered by metabolic stress, hormonal changes, or medications. Common triggering events are acute febrile illness; severe infection; major surgery; severe trauma; postpartum hormonal changes, particularly a decrease in estrogen; hypothyroidism; discontinuing estrogen-containing medication; crash dieting; low protein intake; heavy metal ingestion; and iron deficiency. Many medications have been linked to telogen effluvium, but the most common are beta-blockers, retinoids (including excess vitamin A), anticoagulants, propylthiouracil, carbamazepine, and immunizations.


Telogen effluvium can occur in people of any age, any gender, and any racial background. The exact prevalence of telogen effluvium is not known, but it is considered to be quite common. A large percentage of adults experience an episode of telogen effluvium at some point. Telogen effluvium can occur in either sex, though women have a greater tendency to experience this condition because of postpartum hormonal changes. Also, women are more disturbed by hair shedding than men and are therefore more likely to seek medical attention. [6][7][8][9]


Telogen effluvium is triggered when physiologic stress causes a large number of hairs in the growing phase of the hair cycle (anagen) to abruptly enter the resting phase (telogen). The growth of the telogen hairs ceases for 1 to 6 months (on average 3 months), though this cessation of growth is not noticed by the patient. When the hairs reenter the growth phase (anagen), the hairs which had been suspended in the resting phase (telogen) are extruded from the follicle, and hair shedding is observed.


Histologic findings in telogen effluvium are best seen in transverse sections of a punch biopsy.

  • The number and density of hair follicles are usually normal, but there is an increased percentage of the hair follicles that are in the catagen or the telogen phase.
  • If 25% of the follicles are in the telogen phase, the diagnosis of telogen effluvium is confirmed.
  • The percentage of telogen hair should not typically be higher than 50%.

History and Physical

Patients will report hair shedding, usually without other symptoms, with a relatively abrupt onset. By definition, in acute telogen effluvium, shedding lasts less than six months; often the period of shedding is much shorter. A careful history will identify a causative event (see etiology section) occurring approximately three months before the onset of the shedding (range from 1 to 6 months). Quite often the patient has fully recovered from the acute illness and fails to see the connection between the illness with the hair loss.

The physical examination is grossly normal, as it is difficult for the casual observer to appreciate the loss of hair volume. It can be helpful to compare the patient's current appearance with old pictures. If the patient presents during the acute shedding, a gentle pull test yields at least four hairs removed with each pull. However, if the patient presents after the acute shedding has passed, the pull test may be normal. Careful examination of the scalp will show an increased percentage of short anagen hairs growing close to the scalp.


Usually, a careful history and physical examination are sufficient to diagnose telogen effluvium. Biopsy, if taken during the acute shedding phase (when the pull test is positive), can confirm an increase in the percentage of telogen hairs. If there is a concern for a hormonal condition (such as hypothyroidism), a chronic metabolic illness, or iron deficiency, testing for these conditions is indicated.[10][11]

Laboratory Testing

Chronic telogen effluvium sometimes has a metabolic cause.

  • Hypothyroidism
  • If symptoms of hypothyroidism are present, a thyrotropin test is warranted

Iron Deficiency

  • Iron deficiency should be evaluated with a complete blood count, serum iron, iron saturation, and ferritin.
  • Blood is more important to survival than hair, so the body will shed hair before red cell indices become microcytic.
  • Ferritin behaves as an acute-phase reactant, and inflammation can result in normal ferritin levels in an individual who is iron deficient.
  • Low ferritin confirms iron deficiency; a normal ferritin level does not exclude iron deficiency.
  • Iron saturation is the most sensitive indicator of iron deficiency.


  • If syphilis is considered a cause, a rapid plasma reagin or VDRL test should be performed.


  • Scalp biopsy is the most useful test to confirm the diagnosis, but it is seldom necessary if gentle hair pull produces numerous telogen hair.
  • Telogen hair can be identified by a white bulb and no gelatinous hair sheath.
  • If a patient is unwilling to allow a scalp biopsy, serial hair collections can be obtained.
  • The patient should be instructed to collect all shedding hair in a 24-hour period. The patient should avoid washing the hair during the collection. This process should be repeated every week for a total of three or four collections.
  • Collecting 100 hairs or more hairs in a 24-hour period suggests telogen effluvium. If the collections are performed over several weeks while the telogen effluvium is improving, the number of hairs collected may decrease. 

Treatment / Management

Acute telogen effluvium is a self-limited condition. If the causative event is identified by history and has been adequately treated, no further treatment is required. If a hormonal or dietary imbalance or metabolic illness is present, hair growth will return after these factors are corrected. If a medication is the cause of the shedding, hair growth will restart after the medication is withdrawn.

Hair transplantation has no role in the treatment of telogen effluvium.

While topical minoxidil has not been proven to promote recovery of hair in telogen effluvium, it has theoretical benefits. Patients who wish to take an active role in their treatment may choose to use minoxidil.

Differential Diagnosis

The differential diagnoses of telogen effluvium include:

  • Alopecia areata
  • Anagen effluvium
  • Androgenetic alopecia
  • Scarring alopecia
  • Syphilis
  • Trichotillomania


Morbidity is generally limited to mild cosmetic changes which are mild. Mortality has not been reported.

  • Telogen effluvium has a major impact on those affected by the disease.
  • The prognosis for a good recovery of hair density occurs in acute telogen effluvium.
  • A good cosmetic outcome is also expected in chronic telogen effluvium, even if the hair shedding continues.


Telogen effluvium is a benign and spontaneously reversible condition, there are no complications associated with it.

Deterrence and Patient Education

It may take up to six months for hair growth to restart, and even longer for the growth to be appreciable by the patient. Patients often require the reassurance of the normal recovery of their hair while the hair reenters anagen and grows normally. Patients may also worry that normal grooming of their hair worsens the hair shedding. Patients should be reassured that their hair is normal and that they can wash and style their hair as usual.

Enhancing Healthcare Team Outcomes

The diagnosis and management of hair loss are with an interprofessional team that includes a dermatologist, primary care provider, nurse practitioner, and internist. One type of hair loss is telogen effluvium, which is a form of nonscarring alopecia characterized by diffuse, often acute hair shedding. In most cases, no cause is ever found. In any case, patients need to be educated that the condition is self-limiting. There is no need to prescribe hair growth medications or refer the patient for a hair transplant. The hair growth will return but it may take a few months or even a year. For most patients, the outcome is good.[12][13](Level V)



Dahlia Saleh


5/29/2023 5:02:33 PM



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