Keratosis pilarishttps://en.wikipedia.org/wiki/Keratosis_pilaris
Keratosis pilaris is a common, autosomal-dominant, genetic condition of the skin's hair follicles characterized by the appearance of possibly itchy, small, gooseflesh-like bumps, with varying degrees of reddening or inflammation. It most often appears on the outer sides of the upper arms (the forearms can also be affected), thighs and face (chin). Often the lesions on the face may be mistaken for acne.

Keratosis pilaris is a common disorder of the hair follicle that occurs in children. How common keratosis pilaris is in adults is unclear, with estimates ranging from 0.75 to 34% of the population. Treatment includes the application of topical preparations of moisturizers and medications such as glycolic acid, lactic acid, salicylic acid, or urea to the skin.

○ Treatment ― OTC Drugs
#12% lactate lotion [Lachydrin]
  • For moderate cases, a 12% lactate lotion can be used.
  • Keratosis pilaris ― arm
  • It can also occur on the lower extremities, but in most cases, it is found on the upper arms.
  • Typical case
  • Keratosis pilaris (moderate degree)
References Keratosis Pilaris 31536314 
NIH
Keratosis pilaris is a chronic condition most common in the adolescent population. The condition characteristically presents with papules with follicular involvement and surrounding erythema typically located on the extensor surfaces of the proximal upper and lower extremities. Keratosis pilaris is an asymptomatic condition that generally improves over time. The topical treatments include emollients and topical keratolytics. Skin texture improves with the use of either salicylic acid lotion 6% or urea cream 20%.