This is a form of alopecia that is caused by the child's twisting or pulling of his or her own hair. This cause of hair loss is usually easy to recognize. There is often, but not always, a parental awareness of hair-pulling behavior sometimes while the child is studying or watching television or at bedtime. The area of hair loss is usually asymmetric and follows an irregular pattern. Examination of the involved area reveals hair that are broken off at different lengths. There is never the total hair loss of alopecia areata or the scaling and erythema of tinea capitis. In most cases, trichotillomania is evidence of an innocent and benign habit that is best compared to nail biting. However, trichotillomania may sometimes be evidence of more severe emotional distress or a manifestation of obsessive-compulsive disorder. In addition, children who swallow their plucked hair may develop a gastric trichobezoar. The daily application, by the child if possible, of petrolatum to the affected areas is a useful maneuver. It serves as a reminder to stop pulling or twirling, and it makes the hair slippery and hard to pull out.