A 2-month-old, white, male infant had a 1-month history of a rash that began on the left face and spread to involve the scalp and right lower abdomen. According to his mother, the lesions appeared to be exacerbated by sun exposure. Prenatal and medical history were unremarkable. There was no family history of rheumatologic or autoimmune disease. Aside from the skin eruption noted, the results of the remainder of the physical examination were normal with no evidence of cardiac abnormalities or hepatosplenomegaly. A complete blood cell count with differential, liver enzyme profile, and a basic chemistry panel were all normal, and a skin fungal culture was negative. Antinuclear antibody (titer of 1:320) and anti-La/SSB antibody were both positive, but surprisingly, anti-Ro/SSA antibody was negative. Complete cardiac evaluation results were normal, including a normal electrocardiogram and echocardiogram. Although his mother was clinically asymptomatic, she also had a positive antinuclear antibody and anti-La/SSB antibody but negative anti-Ro/SSA antibody and negative double-stranded DNA. By 4 months of age, all of the cutaneous lesions had resolved spontaneously with aggressive sun protection, and no new clinical symptoms or physical findings were noted.