Trichorrhexis nodosa is a defect in the hair

Hair

Hair is a filamentous biomaterial, that grows from follicles found in the dermis. Found exclusively in mammals, hair is one of the defining characteristics of the mammalian class....

 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

Genetics

Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

 basis but appears to be precipitated by environment

Natural environment

The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

al factors. Among Caucasians 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

Blowdryer

A blowdryer or hairdryer is an electromechanical device designed to blow cool or hot air over wet or damp hair, in order to accelerate the evaporation of water particles and dry the hair. Blowdryers allow to better control the shape and style of hair, by accelerating and controlling the formation...

, aggressive hair brushing

Hairbrush

A hairbrush is a stick brush with rigid or soft bristles used in hair care for smoothing, styling, and detangling human hair, or for grooming an animal's fur.-Human use:...

, and excessive chemical exposure.

In some cases, trichorrhexis nodosa may be caused by an underlying disorder such as argininosuccinic aciduria

Argininosuccinic aciduria

Argininosuccinic aciduria, also called argininosuccinic acidemia, is an inherited disorder that causes the accumulation of argininosuccinic acid in the blood and urine. Some patients may also have an elevation of ammonia, a toxic chemical, which can affect the nervous system...

, Menkes' kinky hair syndrome

Menkes disease

Menkes disease , also called Menkes syndrome, copper transport disease, steely hair disease, kinky hair disease, or Menkes kinky hair syndrome, is a disorder that affects copper levels in the body, leading to copper deficiency...

, Netherton's syndrome, hypothyroidism

Hypothyroidism

Hypothyroidism is a condition in which the thyroid gland does not make enough thyroid hormone.Iodine deficiency is the most common cause of hypothyroidism worldwide but it can be caused by other causes such as several conditions of the thyroid gland or, less commonly, the pituitary gland or...

, argininosuccinic lyase deficiency 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
  Trichoptilosis
  Trichoptilosis , schizotrichia, and informally split ends, is the splitting or fraying of the hair-shaft due to excessive heat and mechanical stress.-Causes:Thermal, chemical or mechanical stress can cause 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

Hair straightening

Hair straightening is a hair styling technique which involves the flattening and straightening of hair in order to give it a smooth, streamlined, and 'sleek' appearance. It may be accomplished by using hair irons and hot combs, chemical relaxers, Japanese hair straightening, or Brazilian hair...

 compounds and permanents should be avoided. The hair should not be ironed. Excessively harsh shampoo

Shampoo

Shampoo is a hair care product used for the removal of oils, dirt, skin particles, dandruff, environmental pollutants and other contaminant particles that gradually build up in hair...

 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.

Prevention

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