Ingrown hair (Hair)
Hair = a long, thin keratinized formation created in the hair follicle, made of 3 layers: The cuticle, the cortex and the medulla.Ingrown hair (of beard) = intradermal penetration and growth of a hair that is too short, causing inflammation and infection. Clinical signs include the appearance of closed erythematous papules and pustules on the shaved area. (Dictionnaire de Dermatologie Jean Civatte Editions CILF)