Hi,
Sometimes a hair shaft fails to grow out of the follicle and stays embedded in the skin. It then starts growing back into the skin. Ingrown hair is nothing serious but it can be a cosmetic concern and can also get infected.
Ingrown hair is called called razor bumps and occurs most often in frequently shaved regions. They typically look and feel like small pimples or cysts and may contain pus. They can cause skin irritation and are more common in individuals with curly and coarse hair.
Genetic predisposition can cause it but dry skin and build-up of dead skin cells in the pores and on the surface of the skin can contribute to its formation.
Hair-removal methods such as shaving, waxing, tweezing and electrolysis often irritate the hair follicle. This results in a boil which traps the hair, and leads to its growth inside the skin.
Treatments for ingrown hairs include shaving in a different direction, exfoliating with facial scrubs or creams containing acids, like salicylic acid.
ref:http://prevention.digitaltoday.in/index.php?option=com_content&task=view&issueid=18&id=1762&Itemid=1
I have had ingrown hair (I assume) on the back of my arms and top of my thighs for the past 6-8 years and I have no clue how to get rid of it... It gets worse in the summer months (fantastic) so I don't know if it is an allergy to something or if it becomes irritated by moisture and/or heat. Years ago a dermetologist tried 5 or six different combinations of different products...which got very expensive and NEVER helped. Nothing helps and scrubbing seems to irritate it more. Let me know if you have any solutions. -C