Pili torti is a rare structural abnormality affecting the hair shaft. Its name is derived from Latin, with “pili” meaning hair and “torti” meaning twisted. This condition is defined by hair shafts that are flattened and twisted at irregular points, giving the hair a distinctive and fragile quality.
Physical Characteristics of Pili Torti
The most notable feature of pili torti is the hair’s texture, which often feels coarse, dry, and stiff. Because the hair shaft is twisted, it reflects light in a way that can create a shimmering appearance. This structural weakness makes the hair brittle and prone to breaking with minimal trauma from brushing or friction.
This constant breakage prevents the hair from growing to a significant length, resulting in short, uneven patches. This can lead to areas of patchy hair loss, known as alopecia, which is common at the back of the head and above the ears. While most commonly affecting the scalp, pili torti can also be present in eyebrows and eyelashes.
Causes and Associated Syndromes
Pili torti has both inherited and acquired causes. In some cases, the condition is isolated, meaning it occurs without any other associated health problems. It can be passed down through families or appear sporadically with no family history. The acquired form is often linked to inflammation and scarring around the hair follicle, which deforms the growing hair shaft.
More frequently, pili torti is a feature of a broader genetic syndrome. For example, it is a characteristic finding in Björnstad syndrome, where it is coupled with sensorineural hearing loss.
Another well-known association is with Menkes disease, a serious disorder of copper metabolism caused by mutations in the ATP7A gene. The lack of sufficient copper affects copper-dependent enzymes that are important for forming strong disulfide bonds in hair keratin. Pili torti is also a feature of Netherton syndrome, which involves significant skin abnormalities and other immune-related issues.
The Diagnostic Process
Diagnosis begins with a physical examination of the hair and scalp. A definitive diagnosis requires microscopic analysis of the hair, a technique known as trichoscopy. This allows for a detailed view of the hair shaft structure without needing to pluck the hairs.
Under the microscope, the defining feature is a flattened hair shaft that is twisted 180° upon its own axis at irregular intervals. This appearance distinguishes it from other hair shaft disorders. If an underlying genetic condition is suspected, further investigations may include hearing tests for Björnstad syndrome or blood tests to measure copper and ceruloplasmin levels for Menkes disease.
Management and Hair Care Strategies
There is no treatment that can correct the underlying structural abnormality of the hair shaft in pili torti. Management is centered on gentle handling practices to minimize breakage. This involves avoiding harsh chemical treatments like dyes, perms, or relaxers that can further weaken the fragile hair structure.
Minimizing the use of heat styling tools like blow dryers and flat irons is recommended. Using a wide-tooth comb rather than a brush helps reduce mechanical stress, and moisturizing shampoos and conditioners can improve hydration. When pili torti is linked to a syndrome, medical management of the underlying disorder is the primary focus. For some children with isolated pili torti, the condition may improve spontaneously after puberty.