Trichorrhexis nodosa

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 people of African origin, 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 hair 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.

Symptoms

• 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.

Treatment

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 hair straightening compounds and permanents should be avoided. The hair should not be ironed. Excessively harsh shampoo should be avoided. Hair conditioners should be used.

Prognosis

This condition is self-limiting. Improvements in grooming techniques and in environmental conditions will correct the abnormality.

Complications

This condition is not dangerous but may affect self-esteem.

Prevention

Avoid aggressive brushing and grooming, strong chemicals, permanents, straightening, and similar hair-damaging habits.

Source

• Trichorrhexis nodosa. MedlinePlus Medical Encyclopedia. US Federal Government public domain. Update Date: 27 October 2003. Updated by: Jeffrey Drayer, M.D., Dermatologist, Los Angeles, CA. Review provided by VeriMed Healthcare Network.