Trichorrhexis nodosa is a defect in the hair shaft characterized by thickening or weak points (nodes) that cause the hair to break off easily. This group of conditions contributes to the appearance of hair loss, lack of growth, and damaged-looking hair.
Causes, incidence, and risk factors
Trichorrhexis may have a genetic basis but appears to be precipitated by environmental factors. Among African Americans, the hair may appear not to grow but microscopic examination shows that the hair shafts have nodes or swellings near the scalp which fracture easily. The hair actually grows but is broken before it can become long. Among whites the defect often appears at the ends of the hair shaft with splitting of the ends, thinning and whitish discoloration.
These conditions are directly related to environmental causes such as “perming”, blow drying, aggressive brushing, and excessive chemical exposure.
In some cases, trichorrhexis nodosa may be caused be an underlying disorder such as argininosuccinicaciduria, Menkes’ kinky hair syndrome, Netherton’s syndrome, hypothyroidism, or trichothiodystrophy.
- lack of apparent hair growth
- hair appears patchy
- hair breaks easily close to scalp
- hair may have thickenings or nodes in the shaft
- ends of hair thinned or split
- whitish discoloration of hair tips
- hair breaks easily at tips
Signs and tests
Examination of the hair shafts with a microscope may reveal changes of trichorrhexis nodosa.
Improving environmental factors will reduce damage to the hair. Gentle brushing with a soft brush should replace more aggressive brushing, ratting, or other procedures. Harsh chemicals such as straightening compounds and permanents should be avoided. The hair should not be ironed. Excessively harsh shampoo should be avoided. Hair conditioners should be used.
This condition is self-limiting. Improvements in grooming techniques and in environmental conditions will correct the abnormality.
This condition is not dangerous but may affect self-esteem.
Calling your health care provider
Try home care measures first (gentle brushing, avoiding chemicals, etc.). If there is no improvement, or if other symptoms begin to appear, call for an appointment with your health care provider.
Avoid aggressive brushing and grooming, strong chemicals, permanents, straightening, and similar hair-damaging habits.
by Levon Ter-Markosyan, D.M.D.