eMedicine Specialties > Dermatology > Diseases of the Adnexa

Telogen Effluvium

Author: Elizabeth CW Hughes, MD, Dermatologist, Group Health Cooperative
Contributor Information and Disclosures

Updated: Mar 27, 2009

Introduction

Background

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.^1,2 Telogen effluvium is a reactive process caused by a metabolic or hormonal stress or by medications. Generally, recovery is spontaneous and occurs within 6 months.

Pathophysiology

Telogen effluvium can affect hair on all parts of the body, but, generally, only loss of scalp hair is symptomatic.

Understanding the pathophysiology of telogen effluvium requires knowledge of the hair growth cycle. All hair has a growth phase, termed anagen, and a resting phase, telogen. On the scalp, anagen lasts approximately 3 years, while telogen lasts roughly 3 months, although there can be wide variation in these times between individuals. During telogen, the resting hair remains in the follicle until it is pushed out by growth of a new anagen hair.

In most people, 5-15% of the hair on the scalp is in telogen at any given time. Telogen effluvium is triggered when a physiologic stress or hormonal change causes a large number of hairs to enter telogen at one time. Shedding does not occur until the new anagen hairs begin to grow. The emerging hairs help to force the resting hairs out of the follicle. Evidence suggests that the mechanism of shedding of a telogen hair is an active process that may occur independent of the emerging anagen hair. The interval between the inciting event in telogen effluvium and the onset of shedding corresponds to the length of the telogen phase, between 1 and 6 months (average 3 mo).

Headington has described 5 functional subtypes of telogen effluvium, based on which portion of the hair cycle is abnormally shortened or lengthened.³ These subtypes represent variations on the principles discussed above. It is rarely possible to distinguish these subtypes clinically.

Frequency

International

This condition is quite common, but exact prevalence is not recorded. A large percentage of adults have experienced an episode of telogen effluvium at some point in their lives.

Mortality/Morbidity

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

Race

No racial predilection is recognized.

Sex

Acute telogen effluvium can occur in either sex if the proper inciting conditions occur. Because hormonal changes in the postpartum period are a common cause of telogen effluvium, women may have a greater tendency to experience this condition. In addition, women tend to find the hair shedding more troublesome than men do; thus, more women seek medical attention for the condition. Chronic telogen effluvium has been reported mainly in women.

Age

Telogen effluvium can occur at any age. It is not uncommon for infants in the first months of life to experience an episode of telogen effluvium.

Clinical

History

The symptom of both acute and chronic telogen effluvium is increased hair shedding. Patients usually only complain that their hair is falling out at an increased rate. Occasionally, they note that the remaining hair feels less dense. In both forms of telogen effluvium, hair is lost diffusely from the entire scalp. Complete alopecia is not seen.

• Acute telogen effluvium is defined as hair shedding lasting less than 6 months. Patients with acute telogen effluvium usually complain of relatively sudden onset of hair loss. Careful questioning usually reveals a metabolic or physiologic stress 1-6 months before the start of the hair shedding. Physiologic stresses that can induce telogen effluvium include febrile illness, major injury, change in diet, pregnancy and delivery, and starting a new medication. Immunizations also have been reported to cause acute hair shedding. Papulosquamous diseases of the scalp, such as psoriasis and seborrheic dermatitis, can produce telogen effluvium.
• Chronic telogen effluvium is hair shedding lasting longer than 6 months. The onset is often insidious, and it can be difficult to identify an inciting event. Because of the duration of the hair shedding, patients are more likely to complain of decreased scalp hair density, or they may note that their hair appears thin and lifeless.

Physical

• The physical examination is the same in both acute and chronic telogen effluvium. Physical findings are sparse. Usually, the physician does not appreciate a decrease in hair density. However, if the patient's hair has been falling out for several months, the hair may appear thin when compared with old photographs.
• Depending on the duration of hair loss, close examination of the scalp may reveal a higher than expected number of short new hairs growing. Because hair grows at a nearly constant rate of approximately 1 cm per month, the duration of the hair shedding can be estimated by measuring the length of the short hairs.
• In active telogen effluvium, the gentle hair pull test will yield at least 4 hairs with each pull. If the patient's active shedding has ceased, the hair pull will be normal. Forced extraction of 10-20 hairs will yield a large percentage of telogen hairs. If greater than 25% of extracted hairs are in telogen, the diagnosis of telogen effluvium is confirmed.
• There is one caveat to reliance on strict physical findings or numerical criteria in the diagnosis of telogen effluvium. Each patient's scalp hair has an individual characteristic growth cycle. There are patients who have a very long anagen phase and a small proportion of hair in telogen at any given time. These patients may experience an episode of telogen effluvium but have completely normal physical findings. History alone must guide the physician to the correct diagnosis in these cases.
• There should be no areas of total alopecia in a patient with telogen effluvium. Scarring is not present. There also should be no sign of an inflammatory scalp dermatitis. Usually, there are no complaints of body hair loss.

Causes

Physiologic stress is the cause of telogen effluvium. These inciting factors can be organized into several categories, noted below. Evidence from mouse studies indicates that psychological stress can induce catagen, mainly by effects on neurotransmitters and hormones.⁴ In humans, however, the role these effects play in hair loss has not yet been determined. While substance P has been extensively studies in human hair follicles in vitro, in vivo studies have not been performed.⁵ In HIV disease, apoptosis may be related to HIV-1 viral protein R.⁶

• Acute illness such as febrile illness, severe infection, major surgery and severe trauma
• Chronic illness such as malignancy, particularly lymphoproliferative malignancy; and any chronic debilitating illness, such as systemic lupus erythematosus, end-stage renal disease, or liver disease
• Hormonal changes such as pregnancy and delivery (can affect both mother and child), hypothyroidism, and discontinuation of estrogen-containing medications⁷

• Changes in diet like crash dieting, anorexia, low protein intake, and chronic iron deficiency^8,9,10
• Heavy metals such as selenium, arsenic, and thallium
• Medications, of which the most frequency cited are beta-blockers, anticoagulants, retinoids (including excess vitamin A), propylthiouracil (induces hypothyroidism), carbamazepine, and immunizations^11,12,13
• Allergic contact dermatitis of the scalp¹⁴

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