Alopecia areatahttps://en.wikipedia.org/wiki/Alopecia_areata
Alopecia areata is a localized condition in which hair is lost from the body. Often, it results in a few bald spots on the scalp, each about the size of a coin. The disease may be caused by psychological stress.

Alopecia areata is believed to be an autoimmune disease related with the immune system of the hair follicles. The underlying mechanism involves failure by the body to recognize its own cells, with subsequent immune-mediated destruction of the hair follicle.

Treatment ― OTC Drugs
Some people with mild alopecia areata recover within a year without treatment. However, most people experience recurrences at random sites on the scalp.
#Hydrocortisone cream

Treatment
Intralesional steroid injections are the most effective treatment. Immunotherapy can be tried if large areas of the scalp are affected.
#Triamcinolone intralesional injection
#DPCP immunotherapy
  • Alopecia areata is seen on the back of the scalp. In typical cases, it appears suddenly with a completely smooth surface and a size of 2-3 cm.
  • Multiple circular hair loss
References Alopecia areata 28300084 
NIH
Alopecia areata is an autoimmune disorder characterized by transient, non-scarring hair loss and preservation of the hair follicle. Hair loss can take many forms ranging from loss in well-defined patches to diffuse or total hair loss, which can affect all hair-bearing sites. Patchy alopecia areata affecting the scalp is the most common type. Alopecia areata affects nearly 2% of the general population at some point during their lifetime. A breakdown of immune privilege of the hair follicle is thought to be an important driver of alopecia areata.
 Alopecia Areata: An Updated Review for 2023 37340563 
NIH
Alopecia areata is an immune-mediated condition leading to non-scarring alopecia of the scalp and other hair-bearing areas of the body. It affects up to 2% of the global population. It can affect all ages, but the prevalence appears higher in children compared to adults (1.92%, 1.47%). A greater incidence has been reported in females than males, especially in patients with late-onset disease, defined as age greater than 50 years. Intralesional injection of corticosteroids has been reported to lead to better responses compared to topical steroids.