What type of alopecia is specifically characterized by patchy areas of hair loss?

Alopecia areata is specifically characterized by patchy areas of hair loss. This autoimmune condition results in sudden, round patches of baldness on the scalp or other areas of the body. The immune system mistakenly attacks the hair follicles, leading to hair fall in specific spots, which can vary in size.

The other types of alopecia listed do not exhibit this characteristic of patchy loss. Diffuse alopecia refers to a general thinning of hair across the scalp rather than in distinct patches. Androgenetic alopecia, commonly known as male or female pattern baldness, leads to a gradual thinning and loss of hair, often following a predictable pattern. Telogen effluvium is a temporary condition where significant stress or trauma leads to hair shedding, affecting the entire scalp rather than creating localized bald spots. Therefore, among the choices, alopecia areata is uniquely noted for its patchy hair loss.