Hereditary Hypotrichosis Simplexof the Scalp

Marıa Rodrıguez Vazquez, M.D.,* Ricardo Ruiz Rodrıguez, M.D.,�Aurora Guerra Tapia, M.D.,* and Luis Iglesias Diez, M.D.*

*Department of Dermatology, 12 de October Hospital and �Department of Dermatology, Ruber Hospital,Madrid, Spain

Abstract: Hereditary hypotrichosis simplex of the scalp is a genotri-chosis characterized by sparse or absent scalp hair without structuraldefects, in the absence of other ectodermal or systemic abnormalities. Wedescribe two Spanish families with hypotrichosis of the scalp. We believethese families have Toribio and Quinones type hereditary hypotrichosissimplex of the scalp.

Hypotrichosis is a common feature of many heredi-tary syndromes, usually in association with other ecto-dermal defects. Scalp involvement as a solitary clinicalmanifestation is unusual (1–3).

In 1974, Toribio and Quinones (4) described a familywith hypotrichosis limited to the scalp. Clinical featuresappeared during early childhood. Inheritance was au-tosomal dominant. Since their first description, fourmore families have been reported (5–8).

Wedescribe two additional families fromSpainwith asimilar hypotrichosis.

CASE REPORTS

In the first family, originally from Cascuera, a smallvillage of Caceres, Spain, a father and son had hypotri-chosis limited to the scalp. No other family member wasaffected. The parents were nonconsanguineous (Fig. 1).

The 38-year-old father had normal beard and bodyhair, but his pubic and axillary hair was sparse. He hadno abnormalities of the teeth, nails, eyes, or sweat glands(Fig. 2).

Microscopic examination of a scalp biopsy speci-men showed a reduced number of hair follicles, most

of them in anagen phase. Cicatricial alopecia was notfound.

His 2-year-old son was diagnosed with subclinicalhypothyroidism due to an ectopic thyroid. He was bornwith normal scalp hair, but hair loss beganwhenhewas 3months old. He had no abnormalities of the eyebrows,eyelashes, sweat glands, eyes, or teeth (Fig. 2).

The second family was originally from Galicia andJaen, and the parents were nonconsanguineous. Thethree brotherswere affectedwith hypotrichosis limited tothe scalp (Fig. 3). Their three sisters and other familymembers were not affected. The two older brothers wereborn with normal scalp hair, but hair loss began at theage of 3 years (Fig. 4). The younger brother presented atbirth with thin, sparse scalp hair.

Physical examination of the three brothers revealedno signs of cicatricial alopecia. Further, there was areduced number of follicles in their scalps. Eyebrows andeyelashes appeared normal. Teeth, nails, and skin had novisible pathology.Trichogramshoweda slight increase inthe number of telogen hairs without existing alterationsin the structure of the hair shaft. Scalp biopsy specimensshowed only aminimal increase in the number of telogenhairs and an absence of scarring.

Address correspondence to Marıa Rodrıguez Vazquez, M.D.,C/Collado Ventoso no. 2, apto 346, 28230 Las Rozas, Madrid,Spain, or e-mail: jmpardal@jazzpapas.com

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Laboratory tests, including a complete blood count,serum chemistry panel, and zinc level, were all withinnormal limits.

DISCUSSION

In 1974, Toribio andQuinones (4) described the first caseof hereditary hypotrichosis simplex (HHS) in a largeSpanish kindred. The features of this entity are 1) theearly onset of hypotrichosis, during the first decade; 2) inadolescence, marked hypotrichosis of the scalp, resultingin nearly complete alopecia by the beginning of the thirddecade; and 3) the hypotrichosis confined to the scalp,with no beard, eyebrow, eyelash, or vellus hair abnor-malities.Males and females are affected equally. The hairmorphology, as well as the scalp and other ectodermaltissues, appear normal. No associated anomalies arefound and intelligence is normal.

This article describes two families with HHS orig-inally from different areas of Spain. In both families, theparents were nonconsanguineous. Hypotrichosis, which

began in thefirst decade,was limited to the scalp. Patientshad no ectodermal abnormalities. Histologic examina-tions of scalp biopsy specimens showed a reduced num-ber of follicles, preponderantly in the telogen phase, withno specific pattern.

Figure 1. Partial pedigree of the first family.

Figure 2. Father and son of the first family, with hypo-trichosis limited to the scalp.

Figure 3. Three brothers from the second family withhypotrichosis.

Figure 4. Older brother of the second family.

Rodrıguez Vazquez et al: Hereditary Hypotrichosis Simplex of the Scalp 149

An autosomal dominant inheritance with full pene-trance has been suggested for HHS in spite of the pres-ence of the disease in the three brothers of the secondfamily in this report.

Only five families with this variant of hypotri-chosis have been described previously (5–8). Aslimited cases of HHS in males may go unnoticed, itis possible that the disorder is more prevalent thansuspected.

REFERENCES

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2. Hess RO, Uno H. Hereditary hypotrichosis of the scalp.Am J Med Genet 1991;139:125–129.

3. Cambiaghi S, BarbareschiM.A sporadic case of congenitalhypotrichosis simplex of the scalp: difficulties in diagnosisand classification. Pediatr Dermatol 1999;16:301–304.

4. Toribio J, Quinones P. Hereditary hypotrichosis simplex ofthe scalp. Br J Dermatol 1974;91:687–696.

5. Khon G, Metzker A. Hereditary hypotrichosis simplex ofthe scalp. Clin Genet 1987;32:120–124.

6. Ibsen HH, Clemmensen OJ, Brandrup F. Familial hypo-trichosis of the scalp: autosomal dominant inheritance infour generations. Acta Derm Venereol (Stockh)1991;71:349–451.

7. Piraccini BM, Misciali C, Fanti PA, Tosti A. Guess what?Eur J Dermatol 1993;3:597–598.

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