Telogen effluvium - introduction

The condition "telogen effluvium" was first defined in 1961 but the symptom it describes, diffuse hair shedding, has been reported in medical literature published throughout the 20th century.

Telogen effluvium forms of hair loss are generalized and diffuse over the scalp and body. Normally, the immune system is not involved - although there are occasional exceptions (Headington 1993). Telogen effluvium usually develops very slowly over a period of several months. Telogen effluvium is not normally a permanent form of hair loss. Eventually, the hair follicles can recover. Recovery and return to normal hair density is very slow and can also take many months.

The name "telogen effluvium" explains the nature of the hair loss very well. All hair follicles in humans run through cycles of activity when they produce hair fiber and dormancy when no fiber is made. Telogen is the name given to the stage of the cycle when a hair follicle is resting. Effluvium is a Latin word that means “letting loose”. So the term “telogen effluvium” describes hair follicles entering a dormant stage and shedding (letting loose) the hair fiber.

In a normal, healthy individual up to 90% of hair follicles are in an a growing phase (anagen) and only 10% are in a telogen, resting phase at any one moment in time. If the percentage of hair follicles in the telogen phase increases significantly then there will be an increase in hair shedding and diffuse thinning of scalp and/or body hair will develop. In extremely rare cases telogen effluvium deteriorates to the stage where almost 100% of hair follicles enter a resting state. When this occurs an individual may develop almost complete scalp hair loss.

The diagnosis “telogen effluvium” is a general term for a variety of hair loss patterns and different causative factors. Whatever the hair loss looks like or whatever caused it, it can described as a telogen effluvium if a significantly increased percentage of hair follicles are in a resting phase than would normally be expected. The early stages of androgenetic alopecia involve an increase in telogen stage hair follicles so telogen effluvium can also occur in other hair loss diseases.

Some trigger factors may promote anagen effluvium and telogen effluvium - even within the same individual. This is a point worth noting when you read through the summary list of trigger factors for telogen effluvium below. When trying to identify a cause of telogen effluvium it must be remembered that the individual may have been first exposed to the trigger factor up to four months before the hair loss was first recognized. It can be very difficult to clearly identify the trigger factor for onset of telogen effluvium.

Potential causes of telogen effluvium overview

There are many potential causes of telogen effluvium. More common causes are listed below and some are explained in greater detail elsewhere.

• Diet deficiencies - Such as lack of vitamins or minerals and particularly iron


• Crash dieting - Starves hair follicles of nutrients they require to grow
  
• Hormones/Pregnancy/Childbirth - Abnormal hormone levels in women especially during and after pregnancy, or a lack of nutrients as the embryo is a drain on supply


• Fever induced alopecia - High body temperatures, in response to infectious chronic disease, stresses dividing cells of the hair follicle and they respond with reduced activity
  
• Ultra violet (UV) radiation - Low dose UV radiation may destroy some of the sensitive hair follicle cells and slow down growth activity


• Acute blood loss - Blood loss effectively starves the hair follicles of nutrients forcing them into reduced activity


• Drugs - Including coumarin, heparin, propanolol, excessive vitamin A intake and many others


• Hyperthyroidism or Hypothyroidism - Thyroid hormones have a profound affect on hair follicle activity


• Neonatal effluvium - Newborns may have diffuse hair loss in the first few months of life


• Extreme physical stress such as surgery - Surgery places extreme physical and emotional stress on the individual and can lead to telogen effluvium


• Emotional stress - Chronic emotional stress or sudden shock can adversely affects hair follicles although the mechanism by which it works is not known


• Severe illness - Severe acute or chronic illness will alter the normal functioning of the body and this may have an impact on hair follicles

Telogen effluvium references

• Rebora A. Telogen effluvium. Dermatology. 1997;195(3):209-12.
• Headington JT. Telogen effluvium. New concepts and review. Arch Dermatol. 1993 Mar;129(3):356-63.
• Guarrera M, Rebora A. Anagen hairs may fail to replace telogen hairs in early androgenic female alopecia. Dermatology. 1996;192(1):28-31.
• Camacho F, Moreno JC, Garcia-Hernandez MJ. Telogen alopecia from UV rays. Arch Dermatol. 1996 Nov;132(11):1398-9.
• Rebora A. Telogen effluvium: an etiopathogenetic theory. Int J Dermatol. 1993 May;32(5):339-40.
• Kligman AM. Pathologic dynamics of reversible hair loss in humans. I. Telogen effluvium. AMA Arch Dermatol. 1961;83: 175-98.
• Sulzberger MB, Witten VH, Kopf AW. Diffuse alopecia in women. AMA Arch Dermatol. 1960;81:556-60