Acquired pili torti--a structural hair shaft defect in anorexia nervosa.

The hair of seventeen girls aged 13 to 19 years with anorexia nervosa (AN) was studied and compared with the hair of fifteen healthy girls aged 13 to 18 years with no complaints of hair loss but with similar habits of hairstyling and care. Light microscopic examination of the hair revealed no defect in the control group. In the AN group, fourteen patients (82.3 percent) had pili torti, an acquired hair shaft defect that has not yet been described in association with this disease. We estimate that the hair defect was due to malnutrition combined with ingestion of exaggerated amounts of yellow vegetables and vitamin supplements, causing a significant increase in levels of serum carotene, retinyl esters, retinol, and retinoic acid. We suggest a possible link between excess vitamin A and pili torti in patients with AN.