Alternative Health
This sounds very much like Alopecia Areata, which is typically indicated by hair loss in patches on the face, scalp or body without any signs of irritation or pain. In short, the follicles are seen as foreign invaders and basically ‘switched off ’ by the immune system because they aren’t recognised by the body. This is why alopecia is often considered to be an autoimmune disorder.
Alopecia can appear without any warning, or there can be a family history. Because the follicles are simply dormant, rather than being permanently destroyed, it is common for the hair to grow back over time. However, the rate of regrowth is highly individual, and alopecia can appear again without warning in the future.