What is the most common sign of neonatal lupus?

The most common sign of neonatal lupus is indeed a discoid rash. This rash is characterized by its circular, raised lesions and can appear on the face, ears, and scalp of infants affected by this condition. Neonatal lupus occurs in some infants whose mothers have autoantibodies associated with systemic lupus erythematosus (SLE). While the rash is the hallmark feature, it is generally transient and tends to resolve on its own without permanent skin damage.

Thrombocytopenia and hemolytic anemia can occur in neonatal lupus, but they are less common compared to the classical presentation of the discoid rash. These hematological manifestations can be serious but are not typically the first sign observed. Hepatitis can also be seen in can be associated with congenital infections rather than neonatal lupus specifically. The discoid rash is the most distinct and recognizable primary indicator when evaluating an infant for potential neonatal lupus.