As many as 60% of untreated cases of Lyme disease can progress to a late stage composed of arthritis [1]. Lyme arthritis develops months to years after the onset of the initial infection, which is characterized by the dermatologic finding known as erythema migrans, as well as constitutional symptoms [2] such as low-grade fever, malaise, and fatigue. Studies have shown that properly treated Lyme arthritis is associated with a good prognosis [3].

Lyme arthritis, which manifests as oligoarticular arthritis, occurs predominantly in the pediatric population [1]. The knee is the most commonly affected site although other joints such as the hip, elbow, wrist, and ankle may be involved [3]. The affected joints are typically swollen but not as painful. Also, patients are susceptible to developing Baker's cysts.

Differential diagnoses include acute septic arthritis and juvenile rheumatoid arthritis (JRA). Less than 20% of children with Lyme arthritis are recognized on initial presentation [4] since it is a late feature of Lyme disease and patients at this point are unlikely to exhibit a rash. Additionally, the symptomology and laboratory findings of these conditions are similar [5].

Complications

Although uncommon, sequelae include bone and cartilage erosion and pannus formation. Furthermore, approximately a tenth of children with Lyme arthritis will experience chronic knee arthritis.

Physical exam

The intermittent episodes of Lyme arthritis are characterized by warm, edematous, and tender joint(s).

• Fever

  Compared with those with septic arthritis, patients with Lyme disease were more likely to have a tick-bite history, knee involvement, and less likely to have a history of fever or elevated temperature at triage. [ncbi.nlm.nih.gov]

  ) mycoses ( B35-B49 ) O'nyong-nyong fever ( A92.1 ) paratyphoid fever ( A01.1- A01.4 ) Type 1 Excludes arthropathy in Lyme disease ( A69.23 ) gonococcal arthritis ( A54.42 ) meningococcal arthritis ( A39.83 ) mumps arthritis ( B26.85 ) postinfective [icd10data.com]

• Chills

  Associated symptoms ranged from none to malaise, fatigue, chills and fever, headache, stiff neck, backache, myalgias, nausea, vomiting, and sore throat. [ncbi.nlm.nih.gov]

  Mild joint pains, fever, chills etc might occur along with the rash for some time. [boneandspine.com]

  Lyme Disease Symptoms Early symptoms resemble a mild flu and include fever, headache, fatigue, chills and swollen lymph nodes. [arthritis.org]

• Rigor

  Lyme disease: a rigorous review of diagnostic criteria and treatment. J Autoimmun. 2015;57:82-115. doi: 10.1016/j.jaut.2014.09.004 Hodzic E, Feng S, Freet KJ, Borjesson DL, Barthold SW. [infectiousdiseaseadvisor.com]

  These guidelines contained a rigorous assessment of the evidence and found treatment failure rates ranging from 16% to 39% for early treatment. Estimates for patients with chronic Lyme disease are much higher, ranging from 26% to 50%. [lymedisease.org]

  “These have not really been looked at with any rigor,” Auwaerter says, which is why he has referred to LLMDs as a “threat to public health.” “The cynic in me says this is a business model for these physicians,” he says. [yahoo.com]

  "Lyme disease: a rigorous review of diagnostic criteria and treatment". Journal of Autoimmunity. 57 : 82–115. doi : 10.1016/j.jaut.2014.09.004. PMID 25451629. Weir, William (19 September 2013). "Lyme Disease Pioneer Stephen Malawista Dies". [en.wikipedia.org]

  Therefore, a more rigorous analysis of myeloid cells recruited to the joint by flow cytometry was performed at various times during infection. [journals.plos.org]

• Arthritis

  Considerable overlap can occur in the clinical presentation of Lyme arthritis and acute septic arthritis. [ncbi.nlm.nih.gov]

• Arthralgia

  This review addresses the clinical presentation of Lyme arthritis as a mono- or oligoarticular relapsing/remitting arthritis primarily affecting the large joints and describes presentations in which arthralgias rather than arthritis are seen. [ncbi.nlm.nih.gov]

  He was treated in the ER one month back for left knee arthralgia with effusion attributed to a twisting injury. The symptoms were resolved following treatment with ibuprofen. [ijcasereportsandimages.com]

  Before the onset of arthritis, 57% of the systemic autoimmune group had the typical erythema migrans skin rash, and an additional 23% had other typical Lyme disease symptoms during the summer such as fever and arthralgias. [medpagetoday.com]

  Twenty percent of untreated persons develop a pattern of waxing and waning arthralgias. Ten percent of patients develop chronic inflammatory synovitis resulting in erosive lesions and destruction of the joint. [boneandspine.com]

• Joint Effusion

  METHODS: The records of all children with an age of eighteen years or less who were managed with aspiration for joint effusions at our institution from 1992 to 2009 were reviewed. [ncbi.nlm.nih.gov]

  Cameron, MD MPH Doctors described a 67-year-old avid outdoorsman from central Pennsylvania with a 3-month history of progressive left knee pain and swelling. [1] There was no history of trauma, tick bite, or rash nor evidence of joint effusion, infection [danielcameronmd.com]

  Radiography and ultrasonography display joint effusion, but this finding is non-specific and not helpful, although the latter imaging technique may be used to monitor the consequences of Lyme arthritis. [symptoma.com]

• Hip Pain

  All patients presented with hip pain (8), limp (3), or refusal to bear weight (5). One of 8 patients had a fever 38.5 C. [ncbi.nlm.nih.gov]

• Joint Deformity

  Of patients with antibiotic refractory arthritis, none in whom followup data were available developed chronic arthritis, joint deformities, or recurrence of infection, supporting current treatment guidelines. [ncbi.nlm.nih.gov]

  Why wouldn’t it through its treachery lead to joint deformity? See this schematic of this grotesque invader. It has a powering rod through the center, known as a longitudinal flagellum. [cassingram.com]

  In the past, surgical intervention was reserved for patients who had already suffered severe joint deformity. [medical-dictionary.thefreedictionary.com]

It is paramount to diagnose Lyme arthritis, septic arthritis, and other similar diseases as early as possible in order to initiate the proper therapy and prevent complications. The workup includes a thorough patient history, an assessment of the risk factors, a physical exam, and the appropriate studies.

Laboratory tests

According to the Centers for Disease Control and Prevention (CDC), the diagnostic system for Lyme arthritis is composed of two steps: 1) enzyme immunoassay (EIA) or enzyme-linked immunosorbent assay (ELISA), which is followed by 2) a confirmatory Western immunoblot test [6] [7]. Generally, testing of serum is not beneficial in the acute stage of the disease.

To rule out differential diagnoses such as septic arthritis, gout or pseudogout, an arthrocentesis may be performed. Joint fluid in patients with Lyme arthritis is typically associated with a white blood count (WBC) of 25,000 to 125,000/µL.

Laboratory findings may include leukocytosis, elevated erythrocyte sedimentation rate (ESR), increased serum aspartate transaminase (AST), and possibly mild hypercomplementemia. Also, rheumatoid factor (RF) and antinuclear antibody (ANA) are negative in patients with Lyme arthritis.

Imaging

Since Lyme and septic arthritis share clinical and laboratory features, this poses a diagnostic challenge [8]. To distinguish between these conditions, authors advocate for the use of magnetic resonance imaging (MRI) in the evaluation of patients with acute arthritis [2]. Specifically, this modality identifies three abnormalities in Lyme arthritis, which are myositis, lymphadenopathy, and absent subcutaneous edema [2].

Radiography and ultrasonography display joint effusion, but this finding is non-specific and not helpful [9] [10], although the latter imaging technique may be used to monitor the consequences of Lyme arthritis [10].

• Blood Culture Positive

  At the time of the blood culture, erythema migrans was present in 4/11 (36.4%) borrelia blood culture-positive patients, i.e. in the patient with borrelial lymphocytoma, the patient with Lyme arthritis and the 2/6 patients with Lyme neuroborreliosis. [ncbi.nlm.nih.gov]

• Synovial Hemangioma

  In conclusion, in children and adolescents synovial hemangioma has to be considered in differential diagnosis of recurrent knee swelling. [ncbi.nlm.nih.gov]

• HLA-DR1

  Among the remaining three patients with chronic arthritis, two had HLA-DR1 alone, and one had HLA-DR3 and HLA-DR7. During the second phase of the study, it was also possible to test for HLA-DRw52 and DRw53 and for the DQ specificities. [nejm.org]

  Differential effect of polymorphism at HLA-DR1 β-chain positions 85 and 86 on binding and recognition of DR1-restricted antigenic peptides. J. Immunol. 150 : 1813 –1821. Sturniolo, T., E. Bono, J. Ding, L. Raddrizzani, O. Tuereci, U. Sahin, M. [jem.rupress.org]

• HLA-B7

  The patient's haplotype was HLA-B7/62 and DRB1*0101/*11. Blood tests showed an increase in the acute phase reactants (erythrocyte sedimentation rate 86 mm/1st h, C reactive protein 80 mg/l), with a normal white blood cell count. [ard.bmj.com]

  HLA-B7, a specificity that cross-reacts with HLA-B27, was found in 43 percent of the patients with chronic arthritis and in 37 percent of those with arthritis of short duration. Nucleotide-Sequence Typing Table 2. Table 2. [nejm.org]

• HLA-DR7

  Among the remaining three patients with chronic arthritis, two had HLA-DR1 alone, and one had HLA-DR3 and HLA-DR7. During the second phase of the study, it was also possible to test for HLA-DRw52 and DRw53 and for the DQ specificities. [nejm.org]

• HLA-Dw2

  A fourth patient had the HLA-Dw13 allele of DR4 (DRβ1*0403), but he also had the HLA-Dw2 allele of DR2 (DRβ1*1501). The fifth patient also had the HLA-Dw2 allele of DR2. DR Phenotypes and Response to Treatment Table 3. Table 3. [nejm.org]

1. Steere AC. Lyme disease. N Engl J Med 2001;345(2):115–125.
2. Ecklund K, Vargas S, Zurakowski D, Sundel RP. MRI features of Lyme arthritis in children. AJR Am J Roentgenol. 2005;184(6):1904-9.
3. Gerber MA, Zemel LS, Shapiro ED. Lyme arthritis in children: clinical epidemiology and long-term outcomes. Pediatrics. 1998;102(4 pt 1):905–908.
4. Culp RW, Eichenfield AH, Davidson RS, Drummond DS, Christofersen MR, Goldsmith DP. Lyme arthritis in children. An orthopaedic perspective. J Bone Joint Surg Am. 1987;69(1):96–99.
5. Marshall S, Hayes EB, Dennis DT. Lyme disease: United States, 2000. MMWR Morb Mortal Wkly Rep. 2002;51(2):29-31.
6. Centers for Disease Control and Prevention. Two-step Laboratory Testing Process. CDC. Available http://www.cdc.gov/lyme/diagnosistesting/LabTest/TwoStep/index.html. March 26, 2015; Accessed:December 14, 2016.
7. Bunikis J, Barbour AG. Laboratory testing for suspected Lyme disease. Med Clin North Am. 2002;86(2):311–340.
8. Willis AA, Widmann RF, Flynn JM, Green DW, Onel KB. Lyme arthritis presenting as acute septic arthritis in children. J Pediatr Orthop. 2003;23(1):114–118.
9. Arvikar SL, Steere AC. Diagnosis and treatment of Lyme arthritis. Infect Dis Clin North Am. 2015; 29(2): 269–280.
10. Czupryna P, Moniuszko A, Czeczuga A, Pancewicz S, Zajkowska J. Ultrasonographic evaluation of knee joints in patients with Lyme disease. Int J Infect Dis. 2012;16(4):e252-5.