Diffuse Alopecia Areata vs Telogen Effluvium

Hi doc,
How do you tell the difference between Telogen Effluvium and Diffuse Alopecia Areata?

Diffuse alopecia areata can look very similar to telogen effluvium. The only way to tell these two diagnosis apart is by performing a series of biopsies of the scalp. Alopecia areata can be diagnosed histologically.