C57-14 Community Acquired Pneumonia Associated With Low Extremity Rash in an Immunocompetent Patient

Abstract Introduction Community-acquired pneumonia (CAP) uncommonly presents with skin manifestations. Cases are more common in immunocompromised patients, as infections tend to spread to multiple organ systems. It provokes a toxic and inflammatory response and manifests as small vessel diseases such as vasculitis or septic emboli. In immunocompetent patients, skin manifestations are rare. Still, they can occur in specific bacterial infections, such as Staphylococcus aureus and Streptococcus pyogenes, Legionella, Rickettsial infections, Mycoplasma pneumoniae, viral infections, including COVID-19, Varicella, and fungal infections like blastomycosis. Case A 74-year-old immunocompetent male presented with remarkable purpuric rash on the lower extremities in the middle of summer. The rash was more prominent on the upper thigh and extended to the lower part of the legs, but the soles of the feet were preserved. They were scattered, flat, non-blanching, and varied in size and shape, resembling petechiae, purpura, or ecchymoses rather than urticaria. After evaluation, the patient was found to have Legionella disease with dense left upper lobe pneumonia as well as Spotted fever group infection. Both diseases were confirmed with Legionella urine antigen and seroconversion of spotted fever group Immunoglobulin (Ig) G antibody. The case became more mysterious as the patient claimed the rash developed after starting the liquid B4 supplement. The skin biopsy revealed a sparse superficial perivascular lymphocytic cell infiltrate without evidence of vasculitis. The patient developed multiorgan failure and eventually expired after 1 month despite aggressive medical treatment. Discussion The patient was a standard resident who had lived in Bergen County, New Jersey, United States. He had worked as an appraiser for over 35 years and often wandered old buildings, and he might have been exposed to wooded, shrubby, or grassy areas. Theoretically, the patient carried a risk of acquiring both diseases, however, as of today, there is no literature describing that these rare diseases could coexist spontaneously. Furthermore, there is no established scientific evidence that the liquid B4 supplement might have interfered with infections. In this case, Rickettsial infection could have been easily missed for several reasons. 1) The prevalence of Rickettsial disease in this area is very low, 2) the initial IgG and IgM titers were unremarkable, and 3) the patient already had a confirmed diagnosis of Legionella disease. Rickettsial infection could be fatal if not adequately treated. Further investigation is warranted if the condition is clinically suspected. This abstract is funded by: none