Generalized Lichen Nitidus in Russell-Silver Syndrome

Abstract

Abstract:  Generalized lichen nitidus is a rare disease, and there are only a few reports associating it with a genetic disorder. Here we report a case of generalized lichen nitidus in Russell-Silver syndrome.

A 5-year-old Japanese girl presented with a 1-month history of papular eruption that gradually spread to her whole body. On examination, numerous small papules were seen on her trunk, head, and extremities. The individual papules were normal skin color, dome-shaped, 1 to 2 mm in size, with a glistening appearance, and with mild pruritus (Fig. 1A). The eruption seemed to spread to her whole body because of the Koebner phenomenon. Skin biopsy of the papule revealed an intense infiltration of lymphocytes and histiocytes into the papillary dermis immediately below the epidermis. The rete ridges at the margins of infiltration were elongated and encircled the infiltrated cells in a “ball-and-claw” manner. The overlying epidermis was thin and exhibited hyperkeratosis. The basal cell layer showed liquefaction degeneration (Fig. 1B). She was treated with a topical, compound of retinoic acid and tocopherol, which was selected because it had the effects of retinoic acid with rare irritation (1). Flattening of papules and remission of pruritus were observed after 6 months of application, but the lesions relapsed after discontinuation of the treatment. She continued without any medical treatment, and her lesions resolved spontaneously after 2 years.

Figure 1.  Clinical features and histological findings. (A) Shiny, dome-shaped, 1- to 2-mm papules on the patient’s back due to Koebner phenomenon. (B) Well-circumscribed lymphocyte and histiocytes infiltration with elongated rete ridges at the margins of the infiltration. (C) Clinodactyly of the patient’s fifth fingers.

The patient had intrauterine growth retardation (birth weight: 1,592 g at the gestational age of 38 wks) and postnatal growth retardation (height 1.37 standard deviations below the mean; weight 26.0% below the mean). She did not have any other endocrinological abnormalities that would cause growth retardation, such as hypothyroidism or growth hormone deficiency. She had the small triangular face, small narrow chin, down-turned corners of the mouth, and fifth-finger clinodactyly that are characteristics of Russell-Silver syndrome (RSS) (Fig. 1C).

From these clinical features, she was diagnosed with RSS, although she had neither maternal uniparental disomy of chromosome 7 nor hypomethylation of paternal imprinting center 1 of chromosome 11p15.5, which are reported in RSS (2).

Lichen nitidus is an uncommon, chronic papulosquamous condition of unknown etiology characterized by multiple shiny, dome-shaped papules. The majority of cases appear in children and young adults (2). The lesions are commonly localized and rarely generalized. Generalized lichen nitidus is sometimes reported in association with a genetic disorder such as Down syndrome, yet to our knowledge, this is a first report of generalized lichen nitidus in a patient with RSS (3,4).

RSS is a congenital disease mainly characterized by severe intrauterine growth retardation (94%) and postnatal growth retardation (99%). Other clinical features include a triangular-shaped face (79%), clinodactyly V (68%), and relative macrocephaly (64%) (2). RSS is classified as an imprinting disorder, and genetic and epigenetic disturbances are detected in approximately 50% of patients. Genetic disturbances include maternal uniparental disomy of chromosome 7 and hypomethylation in the imprinting control region 1 of 11p15.5 (2). Skin manifestations reported in RSS are hyperhidrosis and pigmentation disorders, including café au lait macules or diffuse brown pigmentation with a few small hypopigmented areas (5). Although imprinting disorders show many cutaneous features, it is not clear whether this case is an association between generalized lichen nitidus and RSS or a coincidental case. Further research and reports of similar cases are required to further explore this relationship.