How does that differ from alopecia areata?
If the hair loss is patchy, the early diagnosis is usually alopecia areata, an autoimmune disease. If the hair loss is extensive, only careful study will determine whether it is telogen effluvium or alopecia areata, which comes in different forms and widely differing severities. Patients with short-term patchy disease may be genetically different from patients with extensive disease of long duration. The most common is a patchy, nonscarring hair loss in which one or more circular patches of hair fall out, sometimes overnight. Often as sudden is alopecia totalis, where all scalp hair is lost. Finally, alopecia universalis results in hair loss over the entire body. How long does the typical hair-loss episode last? Alopecia areata can last from days to years and can recur over a lifetime, but most episodes can be successfully treated within several months. Telogen effluvium usually resolves itself without treatment within several months.
