A rare case report: fulminant myocarditis in neonatal lupus erythematosus

Neonatal lupus erythematosus (NLE) is a rare autoimmune disorder caused by the transplacental passage of maternal autoantibodies, such as anti-Ro/SS-A and anti-La/SS-B. It can affect multiple organ systems, resulting in various symptoms. Fulminant myocarditis, a severe inflammatory heart condition and uncommon complication of NLE, may have a favorable prognosis with timely diagnosis and proper treatment.

We present a case of a one-month-old female infant with seizures, hypocalcemia, and a maternal history of Sjögren's syndrome, which are compatible with NLE. Further diagnostic assessments detected anti-nuclear antibodies, anti-SSA, and anti-RO52 antibodies. The infant also exhibited elevated cardiac biomarkers and a reduced left ventricular ejection fraction, pointing to fulminant myocarditis. Treatment with intravenous immunoglobulin and methylprednisolone led to remarkable clinical improvement and normalization of laboratory parameters within one year.

This case highlights the rarity of fulminant myocarditis in neonatal NLE and emphasizes the critical role of early diagnosis and timely intervention. It also indicates the potential prognostic value of cardiac biomarkers in such cases.