72. Lyme arthritis: Antirheumatic therapy or antibiotics?

Abstract

Background: Lyme arthritis is recognised as a cause of inflammatory arthritis, but opinion is largely divided amongst rheumatologists as to whether this is an infectious or an autoimmune manifestation. Aims: To describe a case of juvenile Lyme arthritis and to discuss therapeutic implications History: A 10-year-old girl presented to Paediatric Rheumatology with left knee swelling for 10 weeks. There was no preceding trauma or medical illness. A family friend was treated for TB 2 years prior. A younger sibling had died from Leigh's disease in infancy. On examination she was systemically well with non-specific erythematous macules around the right knee. There was a massive effusion in her left knee and a smaller effusion of the right knee. An USS of the left knee confirmed a large effusion and an Xray was normal. ESR, CRP & LDH were slightly elevated. IGRA (TB Elispot) was negative. Family later remembered frequent exposure to tic-infested deer. A Lyme serology was added to the blood tests. Lyme ELISA was positive and sent to the reference lab, which confirmed positive bands on Western blot (Table 1). Progress: To confer symptomatic relief, joint aspiration was performed. 110 ml of straw-coloured fluid was drawn and was sent for Lyme studies along with a paired serum sample. Physiotherapy was initiated to prevent joint restriction. A 4-week course of high dose oral Amoxicillin was commenced. Within a few days of joint aspiration, there was rapid re-accumulation of the knee joint effusion whist continuing on Amoxicillin. Results of paired joint fluid/serum samples showed concurrent multiple specific bands confirming definite Lyme arthritis (Table 1). Despite completion of the Amoxicillin course, there was persistence of a moderate effusion with arthritis. ESR & CRP had increased to 100 and 76 respectively, with polyclonal hypergammaglobulinemia. A further 4 week course of iv Ceftriaxone was administered which resulted in complete resolution of arthritis and normalisation of inflammatory markers. She has remained (table parsented) well for more than a year, with no arthritis or sequelae having received no intra-articular steroids or DMARDs. Conclusions and Discussion: Lyme arthritis can be difficult to recognise without an appropriate index of suspicion especially as there might not be a clear history of tic bite nor the pathognomonic rash. The first line of therapy for Lyme arthritis as endorsed by the CDC is antibiotics (including parenteral if an oral course fails). Approximately a quarter of children with Lyme arthritis might fail permanent remission with antibiotics, in which case NSAIDs, hydroxychloroquine (thought to have anti-spirochaetal & anti-inflammatory effects), intraarticular steroids and DMARDs have been reported to be useful. In Europe, 4 pathogenic species of Borrelia exist-Borrelia burgdorferi (sensu stricto), B. garinii, B. afzelii & B. spielmanii. In America, B. burgdorferi (sensu stricto) is the only existing species. These different species might exhibit different bands on the Western blot. p58 and OspC have been shown to be indicators of antibiotic refractory Lyme arthritis. However, our patient despite being positive to both these bands, responded completely to antibiotic therapy alone. It is reported in literature that instilling steroids prior to antibiotic therapy in Lyme arthritis might lead to persistent arthritis with persistence of spirochaetal DNA & higher spirochaetal burdens in animal models. Likewise, DMARDS are not advisable in active Lyme infection. The purpose of this synopsis is not for hyper-vigilance where unjustified, but to remind the paediatric rheumatologist of this entity especially in new-onset mono/oligo arthritis and the concern of persistent arthritis if administering steroids or DMARDs before antibiotic therapy in the setting of Lyme disease.