Antinuclear Antibodies in Erythema Multiforme: Transient Occurrence During Acute Illness

Background: Children with target lesions are frequently diagnosed with erythema multiforme (EM). EM was not previously thought to be associated with any specific autoimmune serological abnormality. Methods: We report the case of a 7-year-old girl who developed rashes all over her body with target shaped lesions. Based on clinical appearance and medical history, she was diagnosed with severe erythema multiforme and treated with methylprednisolone. Relevant laboratory tests were performed at admission. Results: At the height of her infection, the antinuclear antibody (ANA) test showed a positive ANA with a titer of 1:100 (speckled pattern) and positive anti-SSA and anti-Ro-52 antibodies. Then she was adjusted for medication. After a week, the infection was relieved, and the re-examination was negative for ANA, anti-SSA, and anti-Ro-52 antibodies. Conclusions: In previously reported EM cases, ANA is generally not considered to be present. The disappearance of ANA during the convalescent phase suggests that ANA is expressed during the acute phase of EM infection. Its correlation with infection severity warrants further research on the mechanism of autoantibody formation in EM.