A desert is a region of land that is very dry because it receives low amounts of precipitation (usually in the form of rain but may be snow, mist or fog), often has little coverage by plants, and in which streams dry up unless they are supplied by water from outside the area.
Alopecia areata is an autoimmune disease. Autoimmune means that the body's immune system attacks the body. When alopecia areata develops, the body attacks its own hair follicles. A person's genetic makeup, combined with other factors, triggers this form of hair loss.
Hair is a cutaneous appendage - just like sweat glands and oil glands. As a result, dermatologists treat ALL forms of hair loss not just the most common form, androgenetic alopecia. There are many forms of alopecia - alopecia areata, telogen effluvium, lichen planopilaris, congenital hypotrichosis.....to name a few.