Hair shaft abnormalities are congenital or acquired defects in the hair strand that are present in various ways. These can range from a simple change in the color of the hair to alterations to its density, length, structure, and growth. Hair shaft abnormalities are often a result of structural changes within the hair fibers that later lead to brittle and uncombable hair. Patients suffering from such dysplasia often have dry, lusterless hair that is significantly fragile, and these disorders can drastically affect a person’s self-esteem. The unhealthy appearance the hair assumes is one of the most common complaints for which individuals seek professional help.

Hair shaft abnormalities can occur secondary to both endo and exogenous etiologies. These include a genetic predisposition in some individuals resulting in deformed hair since birth or acquired hair shaft abnormalities due to vigorous or improper hair care practice. These disorders can be further divided into two subsets: conditions that increase hair fragility and another set of conditions that do not impart such effects.

Below are a few common forms of hair shaft abnormalities frequently encountered by the general population.

Trichorrhexis Nodosa

Trichorrhexis nodosa falls in the category of hair shaft disorders that increase hair fragility. It is characterized by the formation of nodules along the hair shaft that causes the hair to break off easily. The result is a lack of apparent hair growth with damaged-looking hair that frequently has whitish discoloration and split ends on its tips.Trichorrhexis nodosa may be congenital in origin but is usually precipitated by trivial injuries such as chemical or heat burns and aggressive hair brushing, etc. It is regarded as the most common congenital defect of the hair shaft.


In the majority of cases, Trichorrhexis nodosa can be prevented by avoiding hair damaging habits such as aggressive hair brushing and styling, strong chemicals, and heating devices. Fortunately, the condition is self-limiting and improves when healthy hair care routines are restored. These include gentle brushing, using hair conditioners and strengthening serums, and avoiding harsh shampoos, chemicals, and heat ironing during the acute episode.


Monilethrix is a hair shaft disorder that has a characteristic beaded hair strand appearance like a string of beads in a necklace. This is due to the presence of periodic nodes and constrictions along the length of the hair fiber that significantly weakens the hair strands. The resulting brittle hair rarely grows to its maximum potential due to premature breakage, resulting in short sparse hair that breaks easily. The condition most commonly affects the back of the scalp and neck, sparing the front hairline. However, in severe cases, it may involve the whole scalp along with hairy parts of the body such as eyelashes, eyebrows, pubic and axillary hair.

Monilethrix frequently presents in childhood and being a hereditary disorder, is known to run in families.


The condition may spontaneously resolve in many individuals, however, its persistence in adulthood is also frequently reported. Monilethrix is known to improve at puberty, pregnancy, and with the use of oral contraceptives.
Multiple studies show the efficacy of retinoid therapy to impart satisfactory results in individuals suffering from monilethrix. However, relapses are also commonly documented with discontinuation of the drug. Topical and low dose oral minoxidil have also been employed to manage the condition in certain patient populations. Other than medications, a gentle hair care routine and avoidance of harsh chemicals and heating are also recommended to hasten the recovery period.

Bamboo hair

Trichorrhexis invaginata, also known as Bamboo hair, is a disorder in which the hair shaft invaginates itself at several points along its length giving a similar appearance as a bamboo stalk. Under a microscope, several episodic invagination nodules are visible unlike the smooth surface of a normal hair strand. Tricorrhexis invaginate commonly occurs as a feature of a syndrome called the Netherton syndrome, where several other dermatological complaints are also found.

The condition is commonly known to affect hair on top of the scalp, eyebrows, and eyelashes. The affected individuals have hair that is in a knotty bamboo strand-like in appearance and breaks easily. The hair is also dry, lusterless, and short due to frequent breakage.


There is no single modality at present to prevent the occurrence of bamboo hair or provide a complete cure. However, it can be managed to some extent with the use of hydrating and moisturizing products such as conditioners and hair serums. Avoiding products and hairstyling practices that are tough on hair strands are also advised in such patients.

Bubble hair

Bubble hair is an acquired condition, that true to its name has a characteristic bubble-like deformity visible under microscopy. The condition is a consequence of excessive heat treatment to hair strands such as using high heat hairdryers, straighteners, and heating tongs and curls. With the heat, the moisture in the innermost layer of the hair fiber evaporates leaving a bubble-like cavity that is visible under a microscope. This results in hair shafts that are dry, lusterless, and excessively fragile. Bubble hair may also be found in association with other acquired hair shaft disorders such as trichorrhexis nodosa and trichoptilosis.


The best way to prevent bubble hair is to minimize the usage of hair traumatizing devices in daily life. Even when opting for a heat-based styling device one must ensure keeping the temperature to low or medium. Incorporating moisturizing shampoos, conditioners, and hair creams is also believed to be effective for individuals with bubble hair.

Hair Loss or Alopecia

The symptoms of hair loss or alopecia can vary depending on the type. For nonscarring alopecia, the symptoms can include hair loss all over or in circular areas, receding hairline, broken hairs, smooth scalp, inflammation, and possibly loss of lashes, eyebrows, or pubic hair. 

For scarring alopecia, the symptoms can include inflammation at the edge and follicle loss toward the center of lesions, violet-colored skin abnormalities, and scaling. Hirsutism is marked by male pattern hair growth in women, irregular menstruation, lack of ovulation, acne, deepening voice, balding, and genital abnormalities.

Symptoms of hair shaft disorders can include split ends, dry, brittle, coarse hair, skin, and other abnormalities. To tell if you have a hair shaft-related disorder, diagnosis can be made by a Trichologist or dermatologist. Trichoscopy can detect certain hair shaft disorders and distinguish between alopecia and hair shaft disorders.

Frizzy or very coarse hair

The signs and symptoms of a hair shaft disorder related to a hair shaft may include:

Hair loss (alopecia)

• Coarse or frizzy hair

• Uncombable hair – when disordered hair bundles grow in all directions and cannot be arranged by combing

• Fragile hair – hair shafts with reduced tensile strength

• Frizzy hair of unknown cause

• Beaded hair with abnormally thin patches between “beads” or regular-sized sections

• Acquired progressive kinking of hair

• Bubble hair – hair shafts with large “bubbles” within them, thinning the hair cortex and breaking the hair shaft

• Pili annulati – a rare disorder marked by a band-like pattern of alternating thick and thin hairs

• Woolly hair – characterized by thick, curly hair, often grey or white in color


The majority of hair shaft abnormalities are acquired and are secondary to excessive cosmetic treatments. Therefore, these conditions are majorly preventable with adequate hair care and change in hairstyling practices. In general short hair seems to be suitable for patients with hair shaft disorders. Most of the cases positively respond to avoidance of strong external stimulus and nourishing hair care routines. However, it is also essential to seek medical advice when encountering such complaints to exclude any underlying medical conditions.



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