Listeria monocytogenes bacteremia accompanied by skin lesions on the legs.

Objective: We report a case of L. monocytogenes bacteremia accompanied by skin lesions, a rare manifestation of adult listeriosis.

Patient: A Japanese woman in her 80s was hospitalized due to pain in the left leg and difficulty walking. Physical examination revealed diffuse erythema, warmth, swelling, and tenderness in the left thigh and lower leg.

Results: Administration of cefazolin was initiated based on a clinical diagnosis of cellulitis. However, similar erythema appeared on the opposite thigh the following day. Blood cultures obtained on admission yielded L. monocytogenes, prompting a change in antibiotic therapy to meropenem on day 4, followed by ampicillin on day 6. The symptoms in both legs subsequently improved and had nearly resolved by approximately 2 weeks after admission. Antibiotic treatment was continued until day 26. Although the patient died of hepatic dysfunction due to intrahepatic portosystemic venous shunts on day 31, the skin manifestations did not recur during hospitalization.

Conclusion: Even in cases of cellulitis, L. monocytogenes should be considered when blood cultures from older adults yield Gram-positive bacilli, as cephalosporins, often used for the treatment of cellulitis, are inactive against this organism.