This is a disorder that appears due to patients hair pulling behavior. The patient does not accept this and the history is often hollow with no reasonable explanation for hair loss.
Children are more affected and among adults, women predominate.
Typically there is an area of hairloss along the scalp but sparing the margins. The hair loss is not complete and about 0.5 1cm of hair remains. This represents the hair that cannot be pulled in a thumb grip. Various stresses and emotional reactions induce the disorder. It later becomes a compulsive habit.