There is Anagen effluvium and telogen effluvium.
Both of these are not classic male pattern baldness. However, its very important to understand about them.
A lot of hair loss happenings/coincidences can be explained if these 2 are understood.
First, we shall talk about telogen effluvium
Telogen effluvium (TE) In animals, hair/fur goes into synchronized telogen and are shed. This is called telogen effluvium. It occurs in humans during phases of extreme stress, malnutrition, post pregnancy or when under certain drug therapy. For telogen effluvium to occur a significant proportion of hair have to switch from anagen to telogen at the same time. The hair are shed 2 to 3 months later.
Telogen effluvium may be acute or chronic. When hair sheds persistently for more then 6 months, its termed chronic. Chronic telogen effluvium is more common in females.
Acute Telogen effluvium is seen in many infants as a band of hairloss around the occiput that occurs 2 to 3 months after birth.
In order for a large number of hair to simultaneously switch from the anagen phase into the telogen phase, the body has to undergo some systemic injury.
There is usually a lapse of 2 to 3 months between the inciting cause and the hair shed. Therefore, it is often difficult to identify the exact cause in many cases.
A telogen effluvium is not caused by topical medications. But because there is a required time lapse of several months between the inciting cause and the excessive shedding of hair, the exact cause of the telogen effluvium is often not positively identified.
Hair shed is known to occur 2 to 4 months after pregnancy. This can be considered a classic example of telogen effluvium.
Other suspected causes of telogen effluvium include menopause, severe illness, job change, crash diets, major surgery, severe bloodloss, heavy metal poisoning etc. Hyper and hypothyroidism, SLE, end stage renal disease are other reasons. Medications, including anticoagulants, anti inflammatory agents, retinoids, calcium channel blockers etc. are some known causative factors of TE.
In all cases, the common factor is some form of physiologic stress several months before the hair shed.
Diagnosis 1. Hair pull test : Hold a bunch of hair between the thumb and fingers and pull firmly. Unlike in normal conditions, where 2 to 4 hair may shed, one notices a high number of hair coming out. Usually between 20 to 30. This test will be positive even in the scalp areas resistant to pattern hairloss, like the occiput area. At the same time, note that there are no slick bald patches like in alopecia areata.
The hair that get pulled out in the test will be club hair.
An obvious history of an inciting cause and the time frame between the physiological insult and the actual hair shed is usually sufficient to clinch the diagnosis.
A biopsy is usually not required.
Treatment Telogen is actually a variation of a normal hair shedding process, which occurs prematurely and in a synchronized manner in TE. Therefore, there is little in way of treatment except reassurance.
One must eliminate or treat the inciting physiologic event. Assuming there is no repeat of the physiologic insult, the hair should get replaced in 6 to 12 months.
In certain cases, telogen effluvium can coincide with early stages of Male pattern hairloss. In such cases, the hair that replace the shed hair may be miniaturized, giving the impression that the inciting physiologic event gave rise to male pattern hair loss.
Hair transplant is not recommended treatment for Telogen Effluvium.