Case Report of a Rare Cause of Reactive Arthritis: Leptospirosis

INTRODUCTION: Leptospirosis is a zoonosis caused by infection with pathogenic Leptospira species. Leptospirosis has protean manifestations and rare, unusual presentations should be kept in mind in relevant epidemiological scenario. Reactive arthritis refers to acute non-purulent arthritis complicating an infection elsewhere in the body. It is attributed to an immune activation following certain infections; it is, therefore considered as aseptic arthritis. Very few case reports are available attributing leptospirosis as an established cause of reactive arthritis. We present a case of reactive arthritis of the hip joint due to leptospirosis. CASE REPORT: Here, we present a case of a 12-years- old female child who was admitted to our hospital with complaints of fever, headache, and pain in the right hip joint since past 5 days from admission. Subsequent elaboration revealed a past history of fever, headache, and myalgia for around 5-7 days around a week before the present complaints. There was rat infestation near her house and her father was working as sewage cleaner. Routine investigations, Ultrasonography (USG), Magnetic Resonance Imaging (MRI) of both hips and subsequently, diagnostic hip aspiration was performed. USG revealed synovitis, MRI revealed hip joint arthritis of infective or inflammatory origin. Diagnostic hip aspiration was negative for any microorganism. On 10th day of admission, patient started developing icterus with yellowish discolouration of urine. Patient was evaluated for the cause of jaundice. Screening for Leptospira was positive. Synovial biopsy of hip was performed, which showed inflammation with no specific pathology and no growth of any microorganism. In addition, Leptospira IgM MAC ELISA was done which was positive. Patient was thus confirmed to be having leptospirosis and reactive arthritis as a consequence of it. CONCLUSION: The presentation of reactive arthritis secondary to leptospirosis is rare. Leptospirosis can be an etiological factor for reactive arthritis, especially if reactive arthritis is complicated with jaundice.