Systemic Manifestations of Neonatal Lupus in an Infant Born to an Asymptomatic Mother: A Case Report of Anemia and Transaminitis.

BACKGROUND Neonatal lupus erythematosus (NLE) is a rare autoimmune disorder caused by the transplacental transfer of maternal autoantibodies, primarily anti-Ro/SSA and anti-La/SSB. Common clinical manifestations include cutaneous lesions and congenital heart block; however, systemic involvement such as anemia and transaminitis remains infrequently reported, particularly in Southeast Asian populations. Diagnosis is often missed, especially in infants born to asymptomatic mothers. CASE REPORT A 1-month-old full-term female infant born via cesarean section presented with annular erythematous skin lesions since birth, distributed across the face, chest, and extremities. Laboratory tests revealed normocytic normochromic anemia, thrombocytopenia, and elevated aspartate aminotransferase/alanine aminotransferase levels. Although the electrocardiogram was normal, echocardiography showed a secundum-type atrial septal defect and mild tricuspid regurgitation. Skin biopsy revealed histopathological features consistent with cutaneous lupus. Both maternal and infant serology were positive for anti-Ro and anti-La antibodies. A diagnosis of cutaneous NLE with systemic manifestations was established. Prednisone therapy at a dose of 0.5 mg/kg/day was initiated, along with education on how to avoid sun exposure. After 2 months of therapy, the skin lesions had resolved, and laboratory parameters had improved. CONCLUSIONS This case highlights the importance of considering NLE as a differential diagnosis in infants presenting with cutaneous lesions and systemic abnormalities, even when the mother is asymptomatic. Early diagnosis and appropriate treatment can prevent complications and support optimal clinical recovery.