Background: Skin manifestations have been described in 25% of patients with Mycoplasma pneumoniae infection.
Case report: We report a case of Mycoplasma pneumoniae infection in a 29-year-old man who developed a polymorphous erythema-like reaction. Skin manifestations were associated with voluminous lymph node enlargement and high eosinophil levels both in serum and alveolar lavage. Seroconversion against Mycoplasma pneumoniae IgG was documented with ELISA. The clinical course was favorable with erythromycin.
Discussion: ELISA IgG seroconversion is sufficient to confirm the diagnosis of Mycoplasma pneumoniae infection as this test has an 80-90% specificity. This case was unusual by its clinical presentation and high eosinophil counts in serum and tissue samples, similar to what is found in drug-induced hypersensitivity.