Indian Journal of Paediatric Dermatology

CASE REPORT
Year
: 2016  |  Volume : 17  |  Issue : 2  |  Page : 129--131

A curious case of the necklace hair


Mukherjee Samipa Samir, BS Chandrashekar, R Pavan Raj, Chaithra Shenoy 
 Department of Dermatology, Cutis Academy of Cutaneous Sciences, Bengaluru, Karnataka, India

Correspondence Address:
Mukherjee Samipa Samir
Department of Dermatology, Cutis Academy of Cutaneous Sciences, Bengaluru, Karnataka
India

Abstract

Monilethrix is a rare autosomal dominant inheritable hair shaft defect with variable penetrance. The diagnosis is confirmed by the characteristic beaded appearance of the hair under light microscopy which occurs due to defective keratinization. We hereby describe a case of monilethrix syndrome with keratotic follicular papules, moniliform hair, and koilonychias in an 8-year-old Indian female child. A rare association of trichorrhexis nodosa was also noted in our case.



How to cite this article:
Samir MS, Chandrashekar B S, Raj R P, Shenoy C. A curious case of the necklace hair.Indian J Paediatr Dermatol 2016;17:129-131


How to cite this URL:
Samir MS, Chandrashekar B S, Raj R P, Shenoy C. A curious case of the necklace hair. Indian J Paediatr Dermatol [serial online] 2016 [cited 2020 Sep 23 ];17:129-131
Available from: http://www.ijpd.in/text.asp?2016/17/2/129/175660


Full Text

 Introduction



Monilethrix, a term of Greek and Latin origin literally meaning the necklace hair, is a rare autosomal dominant inherited condition with variable penetrance. The first case of monilethrix was described by Walter Smith in 1879. However, the term 'monilethrix' was coined by Radcliff Crocker.[1] It is a structural hair shaft disorder characterized by a beaded appearance due to the presence of elliptical or fusiform nodes which have a diameter of normal hair. These nodes are medullated and separated by areas of constrictions called as internodes which lack medulla. These unmedullated internodes are the sites of hair breakage due to increased fragility. We hereby describe a case of the monilethrix syndrome in an 8-year-old girl characterized by the presence of moniliform hair, follicular keratotic papules, and koilonychia.

 Case Report



An 8-year-old girl, first child, born to second degree consanguineous parents presented with short sparse hair with increased fragility since the 1st year of life. History revealed that the hair was normal at birth which was shortly replaced by short stubby, easily breakable hair that did not grow beyond 3–4 cm. There was no family history of similar complaints. The medical and surgical history in the child was not remarkable.

Scalp examination revealed short, dry, lusterless, fragile, and sparse hair [Figure 1]. The scalp was entirely covered with sheets of tiny keratotic follicular papules predominantly over the frontal and nuchal margin. The child also had sparse eyebrows with marked thinning toward the lateral margins. Follicular papules were noted on the eyebrows as well.{Figure 1}

Cutaneous examination revealed follicular keratotic papules on the lower back. Nails showed koilonychia [Figure 1]e.

The child was of normal height and weight. Ophthalmic, dental, otorhinolaryngological as well as other systemic examination revealed no abnormality.

Microscopic evaluation of the hair shaft revealed regularly interspersed nodes giving rise to moniliform hair or the beaded appearance [Figure 2]a. One of the hair shafts also showed a trichorrhexis nodosa deformity [Figure 2]b. Multiple hair casts were noted on the shafts of hair across the scalp [Figure 3].{Figure 2}{Figure 3}

Dermoscopic evaluation of the hair did not show any detectable abnormality.

The diagnosis of monilethrix was thus confirmed based on the history, clinical evaluation, and microscopic findings.

The child was managed symptomatically with shampoos and conditioners after proper counseling and reassurance to the parents.

 Discussion



Monilethrix is a rare hair shaft defect with autosomal dominant inheritance and variable penetrance. Although, the etiology of the condition remains obscure genetic defects have been implicated in the causation. It has been mapped to the epithelial keratin gene cluster on 12q11–q13 and point mutations have been found in hair-specific keratins, especially hHb1 and hHb6.[2] The most common mutation is the E413K mutation in hHb6. Autosomal dominant monilethrix is caused by mutations in hair keratin genes KRT81, KRT83, or KRT86, whereas in autosomal recessive form, mutations in the desmoglein-4 gene have been reported.[3] Keratin defects lead to decreased tensile strength of the hair fiber thereby leading to increased fragility of the hair shafts. The nodes represent areas of normal keratin formation whereas the internodes form the areas of defective keratinization.

Clinically, the condition is known to affect the scalp hair and eyebrows most commonly, however, other hair-bearing areas such as eyelashes, axillary, pubic, and limb hair are affected occasionally. Due to increased weathering and fragility of the hair shaft the hair fails to grow beyond a certain length giving rise to short stubby hair. It has been associated with keratosis pilaris-like features which were also noted in our case.

Generally monilethrix is not associated with any systemic disturbances, but rare cases have been reported with trichorrhexis nodosa, physical/mental retardation, juvenile cataracts, teeth, and nail abnormalities, syndactyly, and metabolic abnormalities (aminoaciduria).[4] The association of trichorrhexis nodosa was also noted in our case. Although koilonychia was seen there was no association of leukonychia as reported by Narmatha et al. in a case report of Indian siblings.[5]

The diagnosis of monilethrix can be confirmed on light microscopy which shows alternating wider elliptical nodes and narrower internodes. Dermoscopy can be used as a rapid diagnostic tool for monilethrix which may show hair shafts with uniform spindle-shaped nodes and intermittent constrictions (internodes); hairs bent at multiple locations in a regular fashion; and a tendency to shaft fracture at the sites of constrictions.[6],[7] These findings have been described as “regularly bended ribbon” sign by some authors.[8]

No specific therapy exists for the condition. Avoidance of trauma to the hair in the form of physical or chemicals remains the mainstay of therapy. Although literature reveals usage of multiple molecules for therapy ranging from vitamins, retinoids, griseofulvin, iron supplements, steroids, and radiation therapy the treatment remains obscure. Rossi et al. in their report concluded that topical minoxidil 2% can be a good therapeutic option for monilethrix.[9] Few reports have also stated the probability of spontaneous resolution. Our case was managed with shampoos and conditioners with extensive counseling to the patient and parents regarding the benign nature of the disease. Since, other hair shaft disorders such as trichorrhexis nodosa and pili torti show deficiency in cysteine levels in hair keratin, N-acetyl cysteine was tried, which showed slight improvement initially, though this was not persistent as noted by Vikramkumar et al.[10]

To conclude, we in cohesion with Despontin and Krafchik [11] describe monilethrix as a syndrome with moniliform hair, follicular keratotic papules, and koilonychia and also state that the possibility of rare associations such as trichorrhexis nodosa as in our case should be borne in mind.

Declaration of Patient Consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial Support and Sponsorship

Nil.

Conflicts of Interest

There are no conflicts of interest.

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