Telogen effluvium is one of the most common causes of hair loss and is characterized by excessive shedding of resting or telogen hair. The shedding of hair is usually temporary and associated with an insult or stressor that can be physical, mental or chemical. Let us take a look at the presentation, diagnosis and treatment options for telogen effluvium:
Presentation of Telogen Effluvium:
Telogen effluvium usually presents with a diffuse pattern of shedding or hair loss. More hair is noticed falling while washing or combing of the hair and/or more hair is noticed in the drain or on the pillow. It affects both males and females of all age groups, with a higher incidence reported in females in their middle ages. Acute telogen effluvium has a history of hair shedding that lasts for less than 6 months and is generally associated with a stressor/trigger that occurred two to three months before. It is usually self-limiting and hair growth will resolve to normal after 6 to 12 months. A good example is telogen gravidarum, which is an acute hair loss two to five months after childbirth. Chronic telogen effluvium is associated with the shedding of hair lasting for more than 6 months and might involve multiple or repetitive triggers.
Telogen effluvium is caused by an abnormality in the normal hair cycle. A normal hair life cycle has three phases:
Growing phase (Anagen phase)
Involuting phase (Catagen phase)
Resting phase (Telogen phase)
The anagen phase lasts for two to five years and around 85% – 90% of the scalp hair is in this growing phase.
The catagen phase is much shorter and lasts three to six weeks and is when the hair follicles go through a process of programmed cell death known as apoptosis.
The telogen phase lasts for about three to five months and about 10% – 15% of the scalp hair is in this resting phase.
It is normal to lose up to 100 – 150 hairs a day as a result of the normal scalp cycle. Excessive shedding of hair is experienced if the percentage of hair in the telogen phase increases. Thus, paradoxically, with telogen effluvium, hair loss is a sign of hair regrowth.