Antibody Serologies and Diagnostic Considerations in Reactive Infectious Mucocutaneous Eruption.

Reactive infectious mucocutaneous eruption (RIME) is an uncommon, post-infectious mucocutaneous condition often associated with Mycoplasma pneumoniae , but which can be triggered by other pathogens. We retrospectively reviewed eight young adult patients diagnosed with RIME over a 10-year period, all of whom had positive Mycoplasma pneumoniae serology despite negative respiratory pathogen panel PCR results. Findings suggest serology may be more reliable than PCR testing in suspected RIME, as PCR is prone to false negatives due to timing, pathogen load, and sampling challenges. Early serology testing and consideration of empiric treatment targeting Mycoplasma pneumoniae may improve diagnosis and management, though further studies are warranted to guide standardized testing.