From your symptoms it seems that these could be pimples, cysts or Keratosis pilaris. Acne
occurs due to a blockage of oil underneath the skin and builds up with bacteria causing inflammation and develops into a pimple. The common causes of acne are poor diet, stress, genetic, dirt, hormonal imbalances, cosmetics, work-related and drugs. Keratosis pilaris occurs when the human body produces excess keratin, a natural protein in the skin.