|LETTER TO EDITOR
|Year : 2016 | Volume
| Issue : 4 | Page : 330-332
Monilethrix: Clinical and microscopic evidence of improvement with age
Nidhi Kamra, Usha Kataria, Sonia Vashisht
Dermatology OPD, First Floor, BPS Government Medical College for Girls, Khanpur, Kalan, Sonepat, Haryana, India
|Date of Web Publication||7-Oct-2016|
BPS Government Medical College for Women, Khanpur, Kalan, Sonepat - 131 305, Haryana
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kamra N, Kataria U, Vashisht S. Monilethrix: Clinical and microscopic evidence of improvement with age. Indian J Paediatr Dermatol 2016;17:330-2
|How to cite this URL:|
Kamra N, Kataria U, Vashisht S. Monilethrix: Clinical and microscopic evidence of improvement with age. Indian J Paediatr Dermatol [serial online] 2016 [cited 2021 May 6];17:330-2. Available from: https://www.ijpd.in/text.asp?2016/17/4/330/187897
Monilethrix is a heritable hair shaft defect characterized by diffuse or focal alopecia and small node-like deformities that produce a beaded appearance and internodal fragility. It has high penetrance and variable expressivity. The latter characteristic may be partially due to hormonal influences, as cases with improvement in puberty and pregnancy have been reported, and also due to environmental factors such as seasonal changes. Hereby, we report a case of monilethrix in a child with clinical and microscopic evidence of improvement after 8 years of follow-up.
A 14-year-old male, born to second-degree consanguineous parents presented to our outpatient department (OPD) with complaints of sparseness and brittleness of hairs since birth. A similar history was present in mother, maternal aunts, and maternal grandfather. On cutaneous examination, hairs were sparse, short, blonde colored and dry. Multiple minute, skin-colored, follicular papules were present over entire scalp and nape of neck. Hair length above the scalp was around 5–6 cm [Figure 1]. Hairs in other body sites were normal. Nails and mucous membranes showed no abnormality. Examination of other ectodermal derivatives and systemic examination was normal. Laboratory investigations such as complete hemogram, biochemistry profile, and routine urine tests were within normal limits. On the revision of prior records, child presented to the OPD 8 years back with the similar complaint, and hair length at 6 years of age was around 1–2 cm [Figure 2]. On microscopic examination, hair showed characteristic beading and nodes were present at irregular intervals, while 8 years back, hair microscopy showed regular beading with nodes at regular interval of 1 mm [Figure 3]. Thus, patient showed both clinical and microscopic improvement in monilethrix with age.
|Figure 1: Hair shaft length of approximately 6 cm after 8 years of follow-.up|
Click here to view
|Figure 3: Left: 3 nodes with 2 internodes in hair shaft at 6 years of age (×10) Right: increased in nodal length after 8 years of follow-up (×10)|
Click here to view
Monilethrix is an autosomal dominant hereditary defect due to a mutation in the Type II keratins: hHb1 and hHb6. Both hHb1 and hHb6 are primarily found in cortical trichocytes, leading to the assumption that monilethrix is a hair cortex disease thus correlating with the ultrastructural abnormalities present in cortical cells. Few studies have demonstrated that trichocytes (precursor of hair cortex and medulla) undergo alternative directions of differentiation and mesenchymal cells primarily influence their fate. Therefore, monilethrix can be defined as disease of dermal papilla cell-cortical cell dysfunction. Supporting the proposed view, dermal papilla cells are capable of expressing the estrogen receptor in a hair cycle-dependent manner, with highest expression during telogen phase, thus regulating telogen-anagen transition. Although hormonal factors have been suggested to improve monilethrix in females, it role in male hair growth is still questionable.
Affected individuals usually have normal appearing hair at birth and in first few months of life, thereafter hair fibers get sparse, brittle, lusterless, and fail to grow to any appreciable length. In general, a disorder of scalp hair, eyebrows, eyelashes, body hair, and pubic hair may also be affected. Perifollicular erythema and hyperkeratosis can be seen circumscribing the hair shaft on scalp, nape of neck, and other body sites, and this is because thin hairs break inside the scalp and broken hair shaft do not find an easy way out of the infundibulum, disrupt outer root sheath and lead to formation of foreign body granuloma. Monilethrix has also been described as a syndrome involving the triad of moniliform hairs, follicular keratosis, and koilonychia. On microscopy, affected hair shows typical regular, periodic, alternating elliptical nodes, and tapered internodes with normal cuticles.
This case highlights both clinical and microscopic evidence of improvement in monilethrix in a male child with onset of puberty. Although factors leading to improvement in monilethrix in females have been discussed, more studies at genetic and receptor levels are required to elaborate the factors leading to spontaneous improvement of monilethrix in males.
Financial Support and Sponsorship
Conflicts of Interest
There are no conflicts of interest.
| References|| |
Schaap T, Even-Paz Z, Hodes ME, Cohen MM, Hachman-Zadeh S. The genetic analysis of monilethrix in a large inbred kindred. Am J Med Genet 1982;11:469-74.
Limat A, Breitkreutz D, Thiekoetter G, Noser F, Hunziker T, Braathen LR, et al.
Phenotypic modulation of human hair matrix cells (trichocytes) by environmental influence in vitro
and in vivo
. Epithelial Cell Biol 1993;2:55-65.
Oh HS, Smart RC. An estrogen receptor pathway regulates the telogen-anagen hair follicle transition and influences epidermal cell proliferation. Proc Natl Acad Sci U S A 1996;93:12525-30.
Nelson WE. Textbook of Pediatrics. 13th
ed. Philadelphia: WB Saunders Co.; 1987. p. 1425.
Despontin K, Krafchik B. What syndrome is this? Monilethrix syndrome. Pediatr Dermatol 1993;10:192-4.
[Figure 1], [Figure 2], [Figure 3]