Hair Loss Due To Genetic Hair Shaft Defects

A hair shaft defect is any structural abnormality of the hair shaft. Some hair shaft defects are easily diagnosed with the naked eye, others may require microscopic examination. A hair shaft defect is any structural abnormality of the genetic hair shaft. Some hair shaft defects are easily diagnosed with the naked eye, others may require microscopic examination. Hair loss in early childhood represents a broad differential diagnosis that can be a diagnostic and therapeutic challenge for a physician.

It is important to consider the diagnosis of a genetic hair disorder. Genetic hair disorders are a large group of inherited disorders, many of which are rare. Genetic hair abnormalities in children can be an isolated phenomenon or part of genetic syndromes. Hair changes may be a significant finding or even the initial presentation of a syndrome giving a clue to the diagnosis. Detailed history including family history and physical examination of the hair and other ectodermal structures such as nails, sweat glands, and sebaceous glands with the use of dermoscopic devices and biopsy all provide important clues to establish the correct diagnosis. Understanding the pathophysiology of genetic hair defects will allow for better comprehension of their treatment and prognosis. For example, in patients with an isolated hair defect, the main problem is aesthetics. In contrast, when the hair defect is associated with a syndrome, the prognosis will depend mainly on the associated condition. Treatment of many genetic hair disorders is focused on treating the primary cause and minimizing trauma to the hair.

Pili Torti

Is a genetic defect where the hair gets twisted around itself. Due to twisting, the hair breaks off at intermediate lengths leading to diffuse thinning of the scalp which is visible within the first few months after birth.

Tricho Analysis showing the characteristic twisting of the hair strand.

Monilethrix

This is a genetically acquired condition which develops at birth. The hair develops microscopic nodes along the hair shaft. The hair breaks off at the nodes repeatedly because of which the patient can never grow long hair.

Tricho Analysis showing periodic nodes causing beaded appearance of hair shaft.

Pili Annulati

This is a genetically acquired condition in which there are alternating light and dark bands along the hair shaft. The dark areas could be air filled spaces. Such hair is prone to easy breakage.

Tricho Analysis showing alternating light and dark bands along the hair shaft.