Atypical presentation of Lyme disease in a returning traveler: a case report

Lyme disease, caused by Borrelia burgdorferi and transmitted by Ixodes ticks, is rare in South America and is often misdiagnosed in returning travelers. We report the case of a 19-year-old Peruvian male who presented with pruritic erythematous maculopapular lesions and abdominal pain after travel to Maryland, United State of America. His atypical cutaneous findings, including a crusted lesion with ill-defined borders and a maculopapular rash, were initially misinterpreted as bacterial cellulitis, resulting in multiple unsuccessful courses of antibiotics. Further evaluation, guided by his travel history, led to the diagnosis of Lyme disease through serological testing and histopathology. Treatment with doxycycline achieved complete resolution. This case illustrates the diagnostic challenges posed by atypical presentations of Lyme disease in nonendemic regions. Greater awareness among clinicians in South America is essential to recognize imported cases, facilitate early diagnosis, and prevent complications associated with delayed treatment.