L60-L75: Disorders of skin appendages

L63: Alopecia areata

Alopecia areata is a type of hair loss that occurs when your immune system wrongly attacks your own hair follicles, which leads to hair fall. This condition can affect any hair-bearing area on your body, but most often it affects the scalp. Its primary symptom is the appearance of one or more round patches of complete hair loss. For some individuals, the condition can progress to include the entire scalp (alopecia totalis) or the entire body (alopecia universalis). Alopecia areata can develop at any age, but most people experience their first episode of hair loss before age 30. Factors such as family history or certain other autoimmune disorders can increase the risk of developing this condition. Despite its dramatic appearance, the affected hair follicles remain alive and are ready to resume normal hair production whenever they receive the appropriate signal.