Uncombable hair syndrome (pili trianguli et canaliculi, spun-glass hair, cheveux incoiffables)

Are You Confident of the Diagnosis?

What you should be alert for in the history

A young child, often with blond hair who is brought in by parents for “unusual appearing” hair.

Characteristic findings on physical examination

Characteristic, unruly, hair that is difficult to style and has the appearance of standing away from the scalp. It is often “spangled” appearing (Figure 1). There is usually no increase in hair fragility/breakage.

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Figure 1.

Expected results of diagnostic studies

On light microscopic examination of mounted hair, the shaft may have a canal-like longitudinal groove along one or two facets; however this finding is subtle and difficult to detect.

Diagnosis confirmation

When hair cross sections are examined (not an office procedure), the characteristic triangular or kidney- shaped appearance of the hair shaft is diagnostic (Figure 2).

Figure 2.

Who is at Risk for Developing this Disease?

Uncombable hair syndrome is rare; the incidence has not been studied. Inheritance is monogenic autosomal dominant, with imcomplete penetrance. Hair changes are typically noted in childhood, but acquired uncombable hair syndrome has been reported. The distinctive appearance of the hair may only be noted if more than 50% of the hair is affected.

What is the Cause of the Disease?

Etiology

The genetic basis of the disorder/etiology is unknown.

Pathophysiology

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The irregular and changing shapes of the hair cross section prevent adjacent hairs from lying flat or forming locks, and this accounts for the stand away and spangled appearance. It has been suggested that a misshapen dermal papilla may alter the shape of the internal root sheath. Amino acid analysis and x-ray diffraction analysis of the hair is within normal limits.

Systemic Implications and Complications

Uncombable hair syndrome usually occurs without any other associations, although ocular (retinal dysplasia, juvenile cataract), dental (tooth enamel anomalies, oligodontia), digit abnormalities, atopic dermatitis, ichthyosis vulgaris and ectodermal dysplasias (Rapp Hodgkin, as well as other dysplasias classified based on abnormalities of hair, teeth, nail and sweat glands) have been reported in the setting of uncombable hair syndrome.

Uncombable hair syndrome has also been reported to occur in the setting of other hair disorders such as alopecia areata, and loose anagen hair.

Treatment Options

The hair should be trimmed to reduce its volume, and the use of a silicone-based leave-in conditioner may aid in managing the hair. The hair typically improves in appearance over time.

Optimal Therapeutic Approach for this Disease

Uncombable hair syndrome improves with age, without treatment, so that typically by adolescence, the dramatic hair changes are no longer as apparent. Advice to parents of children with uncombable hair syndrome is to treat the hair gently, and to minimize friction on the hair.

Smooth-tipped, wide-spaced combs or brushes should be used along with generous use of hair conditioners, detanglers, and silicone-based hair smoothers(typically sold under the category of anti-frizz products). Excessive brushing, heat, and chemicals should be avoided.

Biotin supplementation (5mg daily) has been reported to improve the appearance and manageability of the hair in a few case reports. The mechanism by which such treatment may improve the hair is unclear, and ultrastructural studies of hair post-treatment have failed to show any ultrastructural changes. However, since biotin supplementation is safe and not costly, a trial may be considered in affected patients.

Patient Management

The hair should be trimmed to reduce its volume, and the use of a silicone-based leave-in conditioner may aid in managing the hair. The hair typically improves in appearance over time.

Unusual Clinical Scenarios to Consider in Patient Management

Many consider the hair findings in the ectodermal dysplasias such as Rapp Hodgkin to be different to uncombable hair syndrome. Although the hair can be unmanageable in Rapp Hodgkin, it is often quite sparse and does not improve with age. Kidney shaped hairs (as well as a longitudinal groove) are usually seen in conjunction with torsion in Rapp Hodgkin, thus the term pili torti et canaliculi has been used by some to distinguish these hair findings from uncombable hair syndrome (pili trianguli et canaliculi).

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Loose anagen syndrome has been observed in association with uncombable hair.

What is the Evidence?

Calderon, P, Otberg, N, Shapiro, J. “Uncombable hair syndrome”. J Am Acad Dermatol. vol. 61. 2009. pp. 512-5. (A case describing a patient with uncombable hair syndrome at age 4, with a follow up showing improved hair growth at age 12. A detailed review of the literature is also included.)

Boccaletti, V, Zendri, E, Giordano, G, Gnetti, L, De Panfilis, G. “Familial Uncombable Hair Syndrome: Ultrastructural Hair Study and Response to Biotin”. Pediatr Dermatol. 2007. (Report of a family with 4 generations of uncombable hair syndrome. Although biotin supplementation improved appearance of hair, ultrastructural changes were not noted.)

Jarell, A, Hall, M, Sperling, L. “Uncombable hair syndrome”. Pediatr Dermatol. vol. 24. 2007. pp. 436-438. (A report of a case and literature review.)

Lee, AJ, Maino, KL, Cohen, B, Sperling, L. “A girl with loose anagen hair syndrome and uncombable, spun-glass hair”. Pediatr Dermatol. vol. 22. 2005. pp. 230-3. (A 4 year old girl with features of loose anagen syndrome with uncombable hair is presented. The hair had an unusual ’bending’ that had not been previously reported.)

Fritz, TM, Trüeb, RM. “Uncombable hair syndrome with angel-shaped phalango-epiphyseal dysplasia”. Pediatr Dermatol. vol. 17. 2000. pp. 21-4. (Case report and discussion of differences in hair shaft anomalies in patients with isolated uncombable hair syndrome, and those with associated ectodermal dysplasias.)

Powell, J, Wojnarowska, F, Dawber, R, Slavotinek, A, Huson, S. “Childhood vulval lichen sclerosus in a patient with ectodermal dysplasia and uncombable hair”. Pediatr Dermatol. vol. 15. 1998. pp. 446-9. (A case report of review of uncombable hair as a component of ectodermal dysplasias.)

Kuhn, C, Helm, T, Bergfeld, W, McMahon, J. “Acquired uncombable hair”. Arch Dermatol. vol. 129. 1993. pp. 1061-1062. (Although usually seen in childhood, uncombable hair was observed in a 39 year old woman after she started to use sprionolactone. This condition may be seen as an acquired form in adults.)

Shelley, W, Shelley, E. “Uncombable hair syndrome: observations on response to biotin and occurrence in siblings with ectodermal dysplasia”. J Am Acad Dermatol. vol. 13. 1985. pp. 97-102. (A report on the benefits of biotin supplementation.)

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