Cutaneous electron microscopic study of sclerodermia diffusa in childhood

A 9-year-old Japanese boy presented in July 1994 with gradual skin sclerosis of the extremities and Raynaud's phenomenon of 10 months duration. He had been treated with oral prednisolone after the diagnosis of juvenile rheumatoid arthritis at the pediatric clinic. He had skin sclerosis with luster on his trunk and extremities (Fig. 1A). His skin score was III and IV, with the exception of his face (I, normal; II, edema; III, edematous sclerosis; IV, skin sclerosis; V, skin atropy). His hands showed finger contracture and he had reticular pigmentation on the back of both hands (Fig. 1B). He had no symptoms of digestive and respiratory organs. Laboratory findings were as follows. Full blood count was almost normal, with the exception of hyper-eosinophilia (eosinophil, 10%) and anemia (hemoglobin (Hb), 10.1 g/dL). The erythrocyte sedimentation rate (24 mm/h) was slightly elevated, but C-reactive protein was normal. Serum gammaglobulin (32.2%) and immunoglobulin G (IgG) (2960 mg/dL) were at high levels. Creatine kinase was normal (60 IU/L). An immunologic profile showed anti-nuclear antibody (ANA) × 10,240 and rheumatoid arthritis test × 160. All other immunologic auto-antibodies were negative. A chest X-ray and chest computed tomography (CT) scan revealed no pulmonary fibrosis. X-Ray films of the extremities showed no abnormal findings of the joints. The inner pressure of the esophagus was within the normal range. Thermography of the hands showed no abnormal findings. Electromyography was normal. In siaolography, the apple tree sign was positive. A skin biopsy was prepared from his forearm. Fibrotic changes, including massiveness and homogenization of the collagen fibers in the dermis, were observed (Fig. 2A). Colloidal iron stain showed increased acid mucopolysaccharides in intercollagenous spaces. In the fascia under the fatty tissue, the same hypertrophic change in the collagen fibers and lymphocytic infiltration were seen (Fig. 2B). With an elastica stain, elastic fibers in the dermis and those in the fascia showed different distribution patterns. In the dermis, elastic fibers seemed to be reduced in size, granulated, and fragmented (Fig. 2C). In contrast, in the fascia, they were hypertrophic and band-like (Fig. 2D). From the clinical findings, laboratory profile, and histologic characteristics, our patient was diagnosed as having sclerodermia diffusa (SDD) with sclerodermatous fasciitis (SF). In order to examine the morphologic abnormality of the fragmented elastic fibers in the dermis, we observed them electron microscopically. Their structures were coarse and rough. Microfibrils were irregularly arranged and amorphous materials were not homogeneous (Fig. 3A). They showed vacuolization and irregular deposition of microfibrillar dense zones (Fig. 3B). Other noticeable findings were network-like structures observed in the dermis (Fig. 3C).