Final answer:
Alopecia areata is an autoimmune condition that results in hair loss in round or irregular patches without inflammation of the scalp. It predominantly affects individuals before the age of 30 and is characterized by coin-sized bald patches.
Step-by-step explanation:
The condition where there is hair loss in round or irregular patches without an inflamed scalp is known as alopecia areata. Alopecia areata is an autoimmune disorder in which the immune system mistakenly attacks the hair follicles, leading to the loss of hair on the scalp and, in some cases, on other parts of the body. This condition can affect anyone regardless of age and gender, though most cases occur before the age of 30. It's characterized by the sudden appearance of smooth, coin-sized patches of baldness on the scalp or other areas of the body where hair grows.