What is telogen effluvium?

As a dermatologist with a focus on hair and scalp disorders, I'm often asked about conditions that affect hair growth and loss. One such condition is telogen effluvium, a common cause of hair loss that can be quite distressing for those who experience it.

Telogen effluvium is a type of nonscarring alopecia, which means it does not result in permanent hair loss. It is characterized by diffuse hair shedding, meaning hair is lost all over the scalp rather than in a specific pattern. This type of hair loss often has an acute onset, meaning it can start quite suddenly and can be triggered by a variety of factors.

The condition can be classified into two forms based on the onset and duration:


1. Acute Telogen Effluvium: This is the sudden form of hair loss that can occur after a significant event that causes physical or emotional stress. Common triggers include:
- Major surgery
- Severe illness
- Childbirth
- Crash diets
- Psychological stress


2. Chronic Telogen Effluvium: This form develops more gradually and can last for months or even years. It may be less noticeable initially, but over time, the hair loss becomes more apparent. Chronic telogen effluvium can be associated with:
- Ongoing medical conditions such as anemia, thyroid disorders, or polycystic ovary syndrome (PCOS)
- Long-term use of certain medications
- Nutritional deficiencies
- Chronic stress

The process of telogen effluvium is a reactive process. This means it is a response to a triggering event that causes a disruption in the normal hair growth cycle. Normally, hair grows in a cycle that includes three phases: the anagen (growth) phase, the catagen (transitional) phase, and the telogen (resting) phase. In telogen effluvium, a significant number of hair follicles are prematurely pushed into the telogen phase, leading to increased shedding as these hairs are shed during the normal telogen-to-anagen transition.

It's important to note that telogen effluvium is not caused by a defect in the hair follicles themselves; rather, it is a response to a metabolic or hormonal stressor or medication. This is a key point because it means that once the underlying cause is addressed, hair growth can typically return to normal.

Diagnosis of telogen effluvium usually involves a thorough history and physical examination. A dermatologist may also perform a trichogram, which is a test that involves gently pulling a small number of hairs to assess the proportion of hairs in the telogen phase. Other tests may be done to rule out other causes of hair loss, such as iron deficiency, thyroid dysfunction, or autoimmune diseases.

Treatment for telogen effluvium focuses on identifying and addressing the underlying cause. This may involve:
- Adjusting or stopping medications that may be contributing to hair loss
- Treating underlying medical conditions
- Ensuring adequate nutrition and addressing any nutritional deficiencies
- Managing stress through relaxation techniques or counseling

In most cases, hair regrowth can be expected once the triggering event has been addressed. However, it's important for individuals experiencing hair loss to seek medical advice to ensure proper diagnosis and treatment.

In conclusion, telogen effluvium is a common and usually temporary form of hair loss that is triggered by various stressors. With appropriate management of the underlying cause, hair typically grows back, and the condition resolves.

Telogen effluvium is a form of nonscarring alopecia characterized by diffuse hair shedding, often with an acute onset. A chronic form with a more insidious onset and a longer duration also exists. Telogen effluvium is a reactive process caused by a metabolic or hormonal stress or by medications.Jun 13, 2017