Juvenile amyopathic dermatomyositis - Systemic lupus erythematosus overlap syndrome

A 10-year-old child referred to our Rheumatology clinic with erythematous, desquamating skin lesions and arthralgia, mainly in the elbow and wrist joints. He did not complain of myalgias, muscle weakness or dyspnea. He had history of epilepsy for two years and nephrotic syndrome for five years. The patient denied photosensitivity, hair loss, oral ulcers, and Raynaud’s phenomenon. There was no known family history of autoimmune disease. On examination, he had slight heliotropic periorbital rash, erythematous elbows, and desquamating papules (Figure 1). No muscle weakness was noted. The patient used the drug (Levetiracetam 500 mg 2×1 / Deltacortil 5 mg 2×1 posology) for epilepsy and nephrotic syndrome. Laboratory: Complete blood counts were normal. Erythrocyte sedimentation rate was 16 mm/h (normal range 0–20 mm/h), C-reactive protein was 0.78 mg/dl, aspartate aminotransferase was 16 IU/L, alanine aminotransferase was 22 IU/L, creatine kinase was 30 IU/L, myoglobin was 25 IU/L, lactate dehydrogenase was 65 IU/L, albumin was 2.5 g/dL, high antinuclear antibody positivity was (4+) and anti-doublestranded DNA (anti-ds DNA) antibodies positive and anticardiolipin antibodies IgG was 120 IU/L. Anti-Jo-1 antibody was negative. Serum complement levels were low with a C3 of 36 mg/dL (normal range: 101–186 mg/dL) and C4 of 6.7 mg/dL (normal range: 16–47 mg/dL). Urinalysis: Kreatinin; 0.6 mg/dl, showed 3+ proteinuria and 24-h urinary protein to creatinine ratio of 7.1 (>3 significant). So renal biopsy was done, which showed WHO stage IV histological-type diffuse glomerulonephritis with mesangial and subendothelial deposits. Our patient had no respiratory symptoms; a chest X-ray was performed but showed no pulmonary involvement. Electromyography was normal and was not indicative of a myopathic pattern. Hand cutaneous biopsy showed a vacuolar alteration of the basal cell layer of the epidermis, necrotic keratinocytes (apoptosis), vascular dilatation, and a sparse, superficial, perivascular lymphocytic infiltrate; immunofluorescence did not show IgG, IgA, IgM, C3 or C4 deposits. The diagnosis of juvenile amyopathic dermatomyositis (ADM) -SLE overlap syndrome was established based on the positive clinical and immunologic findings. The patient satisfied 4 of the 17 criteria of Systemic Lupus International Collaborating Clinics (SLICC) for classifying SLE namely epilepsy, nephrotic syndrome, low serum complement levels, and positive serum antibodies. ADM was Juvenile amyopathic dermatomyositis – Systemic lupus erythematosus overlap syndrome