Hyper- and hypopigmented macules over palms and soles since birth – a case of dyschromatosis symmetrica hereditaria
Published Web Locationhttps://doi.org/10.5070/D39cj4m595
Hyper- and hypopigmented macules over palms and soles since birth – a case of dyschromatosis symmetrica hereditaria1. Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
Iman Hemmati BSc1, Joseph Lam MD2
Dermatology Online Journal 15 (11): 5
2. Assistant Clinical Professor, Department of Pediatrics, Associate Member, Department of Dermatology, University of British Columbia, Vancouver, British Columbia, Canada. firstname.lastname@example.org
Dyschromatosis symmetrica hereditaria (DSH) is a rare autosomal dominant genodermatosis that prominently occurs among Japanese and Korean individuals. Dyschromatosis symmetrica hereditaria presents with a mixture of hyperpigmented and hypopigmented macules distributed on the face and the dorsal aspects of the extremities. We report a case of a 4-year-old girl with DSH and review the pertinent features of this genodermatosis.
Reticulated dyspigmentation in children is uncommon and its causes include benign and serious disorders, some of which may predispose affected individuals to cutaneous and non-cutaneous malignancies. Dyschromatosis symmetrica hereditaria (DSH) is a rare autosomal dominant genodermatosis that prominently occurs in Asians. We present this case to highlight this rare, but distinct cause of reticulate dyspigmentation in Asian children and review the clinical features that distinguish this from other sinister entities.
|Figure 1||Figure 2|
|Figure 1. Hyper- and hypopigmented macules over the patient's hands|
Figure 2. Hyper- and hypopigmented macules over the patient's feet
A 4-year-old girl of Chinese heritage presented to our pediatric dermatology clinic with reticulate hyperpigmentation and hypopigmentation over the dorsum of the hands and feet that were present since birth (Figs. 1 & 2). There is no history of blistering at birth, and there is no history of worsening of the lesion with sun exposure. Moreover, there is no history of pigmentation over the facial areas and no history of reticulate poikiloderma over the cheeks. The patient has had no treatment for these lesions.
|Figure 3||Figure 4|
|Figure 3. Hyper- and hypopigmented macules over patient's father's hands|
Figure 4. Hyper- and hypopigmented macules over patient's father's feet
Past history revealed a normal pregnancy and delivery. Family history is significant for similar lesions over father's hands and feet (Figs. 3 & 4). The review of systems was unremarkable.
On physical examination, the patient had reticulate hyperpigmented and hypopigmented macules over the dorsum of her hands and feet. There was no blistering or xeroderma associated with this. The rest of the physical examination was unremarkable.
Dyschromatosis symmetrica hereditaria (DSH) is a rare autosomal dominant genodermatosis that is characterized by hyper- and hypopigmented macules on the face and dorsal aspects of the extremities that appear in infancy or early childhood. This condition was first described by Toyama in 1929 in Japan . The term reticulate acropigmentation of Dohi is the term that has been commonly applied to this condition in the western literature [1, 2]. Although DSH was traditionally thought to be restricted to Japanese and Koreans, there are reported cases in other ethnic groups such as Europeans and South Americans .
Biopsies of hyper- and hypopigmented macules reveal basal melanosis and hypomelanosis, respectively. Masson-Fontana melanin staining of hyperpigmented macules show abundant melanin pigment both within and outside melanocytes, with little melanin in hypopigmented macules . Electron microscopy reveals small or immature melanosomes scattered sparsely in the melanocytes in the hyperpigmented area, but in the adjacent keratinocytes there are many small melanosomes singly dispersed or aggregated. In the hypopigmented macules, there are melanocytes with numerous vacuoles and small, immature melanosomes. The vacuoles vary in size, and some appear to be degenerative mitochondria and premelanosomes .
A differential diagnosis of DSH should include diseases presenting with reticulated or punctate hyperpigmentation like dyskeratosis congenita, reticulate acropigmentation of Kitamura, dyschromatosis universalis hereditaria, xeroderma pigmentosum, Naegeli-Franceschetti-Jadassohn syndrome, epidermolysis bullosa simplex with mottled pigmentation and Dowling-Degos Disease (Table 1).
Dyskeratosis congenita is a rare progressive bone marrow failure syndrome characterized by reticulate skin hyperpigmentation, nail dystrophy and oral leukoplakia. Unlike DSH, dyskeratosis congenita lacks hypopigmented lesions and involves areas other than hands and feet, such as neck, face and chest. Xeroderma pigmentosum is an autosomal recessive genetic disorder of DNA repair. In addition to the pigmentary changes, patients with xeroderma pigmentosum also have atrophy, telangiectasias, photosensitivity, premature skin aging and malignant cutaneous tumor development. The lesions of two similar benign disorders of pigmentation, dyschromatosis universalis hereditaria and reticulate acropigmentation of Kitamura, differ in that the lesions of the former condition are predominantly on the trunk and the lesions of the latter condition do not include hypopigmented macules. Naegeli-Franceschetti-Jadassohn syndrome is a rare autosomal dominant form of ectodermal dysplasia that has in addition to skin dyspigmentation, defects in sweat glands, nails, and teeth.
Dyschromatosis symmetrica hereditaria is distinct in that it is characterized by asymptomatic hyperpigmentated and hypopigmented macules over face and dorsal aspects of extremities that appear in infancy and early childhood [1, 2, 4]. These lesions usually stop spreading before adolescence and remain unchanged for the rest of the life .
Dyschromatosis symmetrica hereditaria is an autosomal dominant condition with high penetrance. Genomewide searches in families with DSH have determined that mutations in the gene of double-stranded RNA-specific adenosine deaminase (DSRAD), one of the RNA-editing enzymes, are responsible for this condition . It is unknown why low activity of DSRAD induces dyspigmentation of acral skin.
The condition is primarily cosmetic and most treatments attempted have been unsuccessful. Typically, the skin lesions stop spreading before adolescence but persist for life.
Reticulated dyspigmentation in children is uncommon and its causes include benign and serious disorders. We present a case of reticulate acral dyspigmentation in a child with a positive family history to highlight the recognition of the striking but benign pattern of familial acral dyspigmentation that occurs predominantly in Asians.
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