In clinical practice, a hair shaft condition known as trichorrhexis nodosa is seen quite frequently. It is typically the result of weathering caused by either physical or chemical factors. The acquired form of trichorrhexis is the more prevalent of the two types of trichorrhexis. Trichorrhexis nodosa is a condition where your hair easily breaks off at thickened or weak spots (nodes) on the hair shaft.
Trichorrhexis nodosa is most commonly seen in normal hairs subjected to a substantial amount of damage; however, it has also been reported in people with an inherent weakening of the hair shaft because of a structural defect in their hair. Trichorrhexis invaginata (also known as bamboo hair), monilethrix, pili torti, and pseudomonilethrix are structural anomalies associated with greater fragility.
The hairs generated as a result of these illnesses exhibit particular patterns of abnormalities, ultimately leading to brittle hairs. These conditions are passed down through families and can be passed down in either an autosomal dominant or autosomal recessive fashion.
A disease called pili annulate, which affects the hair shaft but does not cause it to be fragile, has been connected with significant hair breakage due to trichorrhexis nodosa. Cases of pili torti are characterized by hairs that are twisted and flattened 180 degrees around the long axis at sporadic points along the shaft. Even though only isolated cases have been described, the mode of inheritance is autosomal dominant.
Pseudomonilethrix hairs have uneven nodes, which might be thought of as the projecting margins of shaft depressions. Hairs that are impacted by the monilethrix have elliptical nodes that are separated by thinner internodes. This indicates that the medulla is absent. Both conditions are passed down through generations in an autosomal dominant fashion.
These structural abnormalities cause hairs to become brittle, making them more sensitive to the effects of trauma. As a result, individuals with these structural defects are more likely to exhibit the nodes of trichorrhexis nodosa.
Keratin synthesis can trigger the fundamental structural fragility of the hair shaft. In patients with trichothiodystrophy, argininosuccinic aciduria, and Menkes disease, the synthesis of keratin in the hair is disrupted, resulting in brittle hair.
Argininosuccinic aciduria is a condition that is caused by an autosomal recessive lack of the enzyme argininosuccinase. This enzyme is necessary for the urea cycle because it converts argininosuccinic acid to arginine and fumaric acid.
Brittle hair and low arginine levels are the symptoms of a rare genetic defect called argininosuccinic acid synthetase deficiency, which causes the enzyme to be absent at birth. In addition, the hair shaft also contains significant amounts of sulfur and the amino acid cystine, which contains sulfur.
They make the production of disulfide bonds possible, which are a contributing factor to the tenacity of the keratin molecule. In individuals with trichothiodystrophy, a deficiency in sulfur and cystine content leads to abnormal keratin production, resulting in weakened hairs. Trichothiodystrophy is characterized by a transverse breakage of the hair shaft known as trichoschisis. However, trichorrhexis nodosa may also be present in affected individuals.
Improving one’s grooming methods and avoiding the use of items that are harmful to hair will assist to correct the issue. This disorder is not harmful, but it can have an adverse effect on a person’s sense of self-worth.
Trichorrhexis nodosa is eventually brought on by trauma, which is true regardless of whether or not there is an underlying abnormality in the hair shaft. As a result, the treatment focuses on reducing the effects of any physical or chemical damage.
It is best to avoid severe hair treatments such as hot combing, excessive brushing, permanent wave styling, and others. It is important to treat the underlying pruritic dermatosis in cases of acquired localized trichorrhexis nodosa to prevent further skin damage from scratching or rubbing. Treating underlying metabolic abnormalities typically involves adopting a diet that has been meticulously crafted for the individual being treated.
The condition distribution across the scalp’s hair can be spotty or more widespread. During the clinical examination, one or more nodes, which appear as whitish spots on the afflicted hair shaft, are located. There is a correlation between shaft length and the number of nodes. Involvement of pubic and body hairs is possible. Especially in situations of acquired localized trichorrhexis nodosa, an evaluation of the skin may show lichenification or a pruritic dermatosis. Both of these conditions cause itching.
The results of a dermoscopy showed breakage in the hair shafts at various levels, generating an image that resembled “thrust paint brushes” and was suggestive of the edges of two brushes that are aligned in opposition. These fibers can be seen in fine detail when viewed with a high magnification power. However, when viewed with a low magnification power, these structures look like light-colored gaps or nodules placed along the hair shaft.
Both electron and light microscopy of the afflicted areas reveal a reduced or missing cuticular cell layer and the paintbrush bristle appearance. It looks like a crushed paintbrush, and medical professionals refer to it as a “paintbrush fracture.”
Patients who have underlying trichothiodystrophy have the characteristic look of alternating dark and light bands on the shaft, which is known as the tiger-tail pattern. This pattern can be seen under polarized light.
In the event that it is required, microscopy and culture of the fungus in question may be conducted. Patients who showed signs of having an inherent congenital illness at a young age and had other symptoms that went along with it should have further testing.
If the hair is analyzed, the hair shaft may disclose a chemical shortage caused by a metabolic condition. Analyses of serum and urine should be done to determine the amounts of amino acids. Tests for copper levels, iron levels, blood cell counts, liver function, and thyroid function are some examples of additional blood tests that experts may perform.
When dealing with acquired trichorrhexis nodosa, the various treatment approaches focus on removing the offending factor that caused the condition. This may result from repeated physical trauma, chemical damage, or other assaults. Experts suggested that the use of conditioners and oils could help prevent the damage done to the cuticle layer of the hair shaft caused by the friction between the hair and the comb, which is the primary factor in the development of the weathering fault.