What is alopecia?
Alopecia is diffuse (global) hair loss. The hair loss can be global, involving all hair bearing surfaces, patchy or in a pattern. There are many different kinds of alopecia and they differ based on their pattern and extent of hair loss.
Are there different kinds of alopecia?
Yes, there are many kinds of alopecia. Alopecia is further classified into scarring and non-scarring alopecia.
What causes alopecia?
The cause of alopecia varies depending on the type of alopecia the patient has. The hair follicle cycle has 3 phases: anagen (growth phase), telogen (quiet phase, no growth and no death), and catagen (dying phase). A defect in the hair cycle can lead to a variety of hair loss or hair growth patterns, depending on what phase is affected. Diffuse hair loss without scarring is caused by failure of hair follicle production, hair shaft abnormalities or abnormal cycling (shedding). Focal and patchy hair loss can be caused by infection, abnormalities of the hair cycle, hormones (androgenetic alopecia) or hair breakage. Stress, immune-system, drugs can all trigger a defective hair cycle.
How is alopecia treated?
The treatment of alopecia varies based on the type:
Wolff K, Johnson, RA. Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology. Sixth Edition. 2009.