460 Archives of Disease in Childhood 1997;76:460–462

RHEUMATOLOGY Arch Dis Child: first published as 10.1136/adc.76.5.460 on 1 May 1997. Downloaded from

Management of childhood . Part 1: acute arthritis

P N Malleson

This is the first article in a Arthritis in childhood is not uncommon. Esti- have been perfectly visible on a much cheaper series on . mates of the annual incidence of arthritis vary radiograph!). widely, but for all forms of chronic arthritis it is probably between 5 and 10 per 100 000 12 Septic arthritis children aged 16 years or younger. Acute Septic arthritis is, of course, a medical forms of arthritis are perhaps four times more 3 emergency and if suspected must be investi- common. Most paediatricians will therefore gated with both blood cultures and arthrocen- see several patients with arthritis each year. 4 tesis for Gram stain, cultures, and tests for spe- The aim of this paper and part 2 of the series cific infectious antigens. Although a high is to give a concise, but moderately comprehen- peripheral white cell count, high erythrocyte sive, overview of this topic which will help in sedimentation rate, and high synovial fluid the management of this heterogeneous group white cell count (>5.0 × 109/l) is suggestive of of disorders. an infection, similar findings can occur in reac- Although chronic arthritis can present with a tive arthropathies and even in early chronic sudden and painful onset of one or more swol- arthropathies. Furthermore, synovial white cell len joints, such a presentation should raise sus- counts may be only mildly increased in proved picions that the arthritis is due to trauma or to septic joints. A significant proportion of a joint or contiguous bone infection. children with probable septic arthritis have persistently negative cultures (even without preceding antibiotic treatment) and negative 5

Trauma antigen tests. Therefore it is probably neces- http://adc.bmj.com/ A traumatic cause of joint swelling is usually sary to treat a few children who may not actu- obvious from the patient’s history, but parents ally have septic arthritis with intravenous anti- sometimes incorrectly presume that a swollen biotics so as not to miss a child who does have joint must have been due to an injury. It is this disorder. Although septic arthritis usually unlikely that an injury is the cause of a swollen aVects only a single joint (usually a knee) in joint if the child has not had a definite children, 4–6% of patients will have two or traumatic event that was painful enough to more joints aVected. Therefore the fact that

immediately prevent the child continuing with several joints are swollen should not lead to the on September 29, 2021 by guest. Protected copyright. the activity. The exception to this is perhaps a exclusion of the possibility of sepsis. child with haemophilia, who might develop a It is fairly common, particularly in neonates, haemarthrosis after only mild trauma. for an osteomyelitis to have an associated If it is uncertain whether the swelling of a arthritis, which may or may not be septic. Bone joint is due to a joint eVusion or simply due to tenderness beyond the margins of the joint is soft tissue swelling, an ultrasound examination suggestive of osteomyelitis. Radiographs often of the joint can be helpful and may also be able show soft tissue changes adjacent to an infected to determine whether there is blood in the bone several days before bone changes become joint. Synovial fluid analysis of a traumatic visible. A bone scan is usually diagnostic of eVusion usually shows a low white cell count osteomyelitis even if the joint has already been (<0.2 × 109/l), but this can occasionally be aspirated. much higher and mimic fluid from a septic The initial treatment of septic arthritis joint. A haemarthrosis raises the possibility of should be with an antibiotic given intrave- Department of either a fracture into the joint or a torn anterior nously, such as cefuroxime, which is eVective Paediatrics, The cruciate ligament. The presence of marrow fat against streptococci, and, Research Centre, Staphylococcus aureus, Vancouver, Canada is indicative of a fracture. if the child has not been immunised, Haemo- Magnetic resonance imaging has revolution- philus influenzae type b, with the antibiotics Correspondence to: ised the investigation of musculoskeletal disor- being changed as appropriate once the organ- Dr P N Malleson, Paediatric ders and it has largely replaced arthrograms in ism has been cultured and its sensitivities Rheumatology, Faculty of Medicine, Department of the investigation of joints aVected by trauma. determined. In a child with septic arthritis of Paediatrics, The Research Magnetic resonance imaging should only be the foot, consideration should be given to using Centre, 950 West 28th performed after a plain radiograph has been an antibiotic eVective against Pseudomonas Avenue, Vancouver, British Columbia, Canada V5Z taken (it is embarrassing to diagnose a fracture aeruginosa. The total duration of treatment 4HA. on magnetic resonance imaging that would should be 4–6 weeks, guided by the clinical Acute arthritis in childhood 461

signs, peripheral white cell count, and erythro- that in areas where the disease is endemic, cyte sedimentation rate. The use of antibiotics many children diagnosed as having chronic Arch Dis Child: first published as 10.1136/adc.76.5.460 on 1 May 1997. Downloaded from given by mouth in high doses once the infection Lyme disease actually have fibromyalgia.13 is under control has been advocated, but requires careful monitoring of compliance Reactive and postinfectious arthritis (ideally with serum bactericidal titres) and An acute arthritis after an infection in which clinical progress.67 Although most authorities there is no evidence of a septic process of the advocate open drainage of a septic hip joint and joint is considerably more common than septic repeated aspirations of other joints, there is lit- arthritis.3 The classical postinfectious ar- tle evidence supporting repeat aspirations.8 thropathy is rheumatic . In recent years a They are probably unnecessary if the child’s form of poststreptococcal arthritis has been course progresses satisfactorily. recognised that is more polyarticular and more It is extremely important to provide ad- prolonged than in typical acute rheumatic fever equate pain relief (something that is often for- and which does not always fulfil the criteria for gotten); this should usually initially be with rheumatic fever, but which may be complicated intravenous morphine. The use of a splint to by carditis.14 It should be suspected in any child ‘rest’ and protect the joint is appropriate for a who has a sore throat or constitutional few days, but should not be prolonged as it will symptoms at the onset of the arthritis and encourage joint contractures and muscle wast- should be investigated with throat cultures and ing. The role of non-steroidal anti- to streptococcus. If a recent strepto- inflammatory drugs (NSAIDs) has not been coccal infection can be proved, then cardiac formally evaluated, but is probably helpful. evaluation with echocardiography should be Whether the use of corticosteroids early in the undertaken. Penicillin prophylaxis is manda- disease course might be of benefit, as has been tory in children with evidence of carditis, but is shown for bacterial meningitis,9 is unknown. controversial if there is no clinical or echocar- Occasionally the inflammatory response ap- diographic evidence that the heart is aVected. pears to persist long after it seems clear that the Arthritis secondary to various enteric infec- infection has been eradicated, and then the use tions is not rare in children. A family history of of NSAIDs or intra-articular corticosteroids, or spondyloarthropathy is often present and most both, seems justified, as it is probably the patients are positive for HLA-B27. The arthri- inflammatory response rather than the bacteria tis can be extremely painful, mimicking sepsis; themselves that is damaging to the joint it is usually relatively short lived, but may occa- cartilage. sionally become chronic. Although there is some evidence that there may be persisting Lyme arthritis antigens in the joint, there is no clear evidence Lyme arthritis is a form of infectious arthritis that antimicrobial treatment modifies the which is common in some areas of the world. It disease course. Treatment is with an NSAID

occurs several weeks to months after the initial such as tolmetin until the joint inflammation http://adc.bmj.com/ infection with Borrelia burgdorferi. It has an has resolved clinically and the complete blood acute oligoarticular onset and tends to be epi- count and erythrocyte sedimentation rate have sodic, with each episode lasting a few days. The normalised. episodic nature of the arthritis is an important Chlamydia trachomatis infection of the geni- clue that this is not idiopathic chronic arthritis. tourinary tract should be considered in any Treatment with erythromycin 30 mg/kg/day or sexually active adolescent with new onset amoxicillin 30–50 mg/kg/day by mouth, both arthritis. Viable chlamydia may persist in the 15 divided twice a day, is usually eVective. If joints of patients with Reiter’s syndrome and on September 29, 2021 by guest. Protected copyright. untreated the arthritis can recur several times a antibiotic treatment of the initial infection as year for several years, but the episodes well of the subsequent arthritis can be gradually decrease in frequency and eventually beneficial.16 Therefore antibiotics as well as resolve completely.10 NSAIDs are justified if this diagnosis is proved. A few children, whether they have been Many acute transient arthritides are prob- treated appropriately or not, go on to develop ably due to viral infections. Rubella infection of chronic arthritis. This outcome is associated both the wild type and after immunisation is a with the presence of antibodies to HLA-DR4 common cause of arthralgias or arthritis in or HLA-DR2 and with high titres to adolescents, but is a rare cause in young the outer surface protein A of Borrelia children. Parvovirus B19 is also a common burgdorferi.11 The problem with managing pos- cause of acute arthritis in adolescents and sible Lyme arthritis is that the diagnosis can be young adults, but, like rubella, it rarely causes diYcult. Only about 40–70% of children have arthritis in young children. Arthritis can occur the characteristic erythema migrans rash, con- after chickenpox, but sometimes this can actu- stitutional symptoms may be mild, and sero- ally be due to a septic arthritis, presumably due logical tests are diYcult to interpret as there is to haematogenous spread from an infected a high incidence of false positivity. Paediatri- lesion. As viral arthritides are self limiting the cians should be wary of treating children with treatment is usually no more than a few days of arthritis without a history of tick bites or NSAID treatment, combined with rest and erythema migrans for Lyme disease, unless other symptomatic measures. there is western blot confirmation of a positive serology, as the risk of antibiotic toxicity is Malignancy probably higher than the risk of complications After trauma and infection the most important from the untreated disease.12 It is worth noting cause of acute or recent onset arthritis is 462 Malleson

malignancy, not because it is a particularly child had meningitis often seem reluctant to common cause of arthritis, but because a delay perform arthrocentesis because of its painful Arch Dis Child: first published as 10.1136/adc.76.5.460 on 1 May 1997. Downloaded from in diagnosis may have such profound conse- nature when they suspect septic arthritis. With quences both for the patient and for the doctor. the use of ‘conscious sedation’ with midazolam Leukaemia and neuroblastoma can both and fentanyl, EMLA cream, and buVered present with true joint swelling. Bone tumours lignocaine, an arthrocentesis should be almost (and uncommonly tumours arising from joint free from pain and anxiety for the child, parent, tissues) can present with joint pain. The true and doctor. cause of the arthropathy should be suspected if the child is constitutionally unwell, if there is I gratefully acknowledge the advice of Dr Richard Beauchamp bone tenderness rather than tenderness limited and Dr Simon Dobson in the preparation of this paper. to the joint line, if there is profound anaemia or a cytopenia, or if the platelet count is not 1 Gäre BA, Fasth A. Epidemiology of juvenile chronic arthri- increased in the face of an increased erythro- tis in southwestern Sweden: a 5-year prospective popula- tion study. J Pediatr 1992;90:950-8. cyte sedimentation rate. High lactate dehydro- 2 Malleson PN, Fung MY, Rosenberg AM, for the Canadian genase levels are a helpful clue that the child Pediatric Rheumatology Association. The incidence of 17 pediatric rheumatic diseases: results from the Canadian has leukaemia. The management of the Pediatric Rheumatology Association Disease Registry. J arthritis associated with a malignancy is the Rheumatol 1996;23:1981-7. 3 Kunnamo I, Kallio P, Pelkonen P. Incidence of arthritis in management of the underlying disease, but the urban Finnish children. Arthritis Rheum 1986;29:1232-8. pain may well be severe enough to warrant 4 Malleson P N. Management of childhood arthritis. Part 2: chronic arthritis. Arch Dis Child 1997 (in press). intravenous morphine during the first few days 5 Fink CW, Nelson JD. Septic arthritis and osteomyelitis in of specific oncology treatment. children. Clinics in Rheumatic Diseases 1986;12:423-35. 6 Nelson JD, Bucholz RW, Kusmiesz H, Shelton S. Benefits and risks of sequential parenteral-oral cephalosporin ‘Rheumatology tests’ therapy for suppurative bone and joint infections. J Pediatr Orthop 1982;2:255-62. Although doctors commonly order tests for 7 Dagan R. Management of acute hematogenous osteomyeli- rheumatoid factor and antinuclear antibodies tis and septic arthritis in the pediatric patient. Pediatr Infect Dis J 1993;12:88-92. in children with acute arthritis in an attempt to 8 Nord KD, Dore DD, Deeney VF, et al. Evaluation of treat- make a positive diagnosis of a rheumatic ment modalities for septic arthritis with histological grading and analysis of levels of uronic acid, neutral disease, this policy is incorrect and should be protease, and interleukin-1. JBoneJointSurgAm1995;77: abandoned. When performed as a screening 258-65. 9 Odio CM, Faingezicht I, Paris M, et al. The beneficial test rheumatoid factor tests are rarely positive, eVects of early dexamethasone administration in infants and when positive are as likely to be in children and children with bacterial meningitis. N Engl J Med 1991; 324:1525-31. with other diseases as in children with chronic 10 Szer IS, Taylor E, Steere AC. The long-term course of Lyme arthritis.18 Positive tests for antinuclear anti- arthritis in children. N Engl J Med 1991;325:159-63. 11 Steere AC, Levin RE, Molloy PJ, et al. Treatment of Lyme bodies using HEp-2 cells commonly occur, but arthritis. Arthritis Rheum 1994;37:878-88. are found as often in children with non- 12 Magid D, Schwartz B, Craft J, Schwartz JS. Prevention of Lyme disease after tick bites. A cost-eVectiveness analysis. rheumatic disease as in those with rheumatic N Engl J Med 1992;327:534-41.

disease (P Malleson et al, unpublished data). 13 Sigal LH, Patella SJ. Lyme arthritis as the incorrect diagno- http://adc.bmj.com/ sis in pediatric and adolescent fibromyalgia. Pediatrics Positive tests for specific antinuclear antibodies 1992;90:523-8. can also occur in various malignancies and 14 Fink CW. The role of the streptococcus in post- 19 streptococcal reactive arthritis and childhood polyarteritis could lead to a delay in the correct diagnosis. nodosa. J Rheumatol 1991;18(suppl 29):14-20. 15 Rahman MU, Cheema MA, Schumacher HR, Hudson AP. Molecular evidence for the presence of chlamydia in the Conclusions synovium of patients with Reiter’s syndrome. Arthritis Acute joint swelling is a disorder that can often Rheum 1992;35:521-9. 16 Lauhio A, Leirisalo-Repo M, Lähdevirta J, Saikku P, Repo be due to a serious underlying disease. It H. Double-blind, placebo-controlled study of three-month should not be dismissed as due to trauma or treatment with lymecycline in reactive arthritis, with special on September 29, 2021 by guest. Protected copyright. reference to chlamydia arthritis.Arthritis Rheum 1991;34:6- the first manifestations of a chronic arthritis 14. without careful consideration of the relevant 17 Wallendal M, Stork L, Hollister JR. The discriminating value of serum lactate dehydrogenase levels in children history and a judicious use of investigations. with malignant neoplasms presenting as joint pain. Arch Although undoubtedly not required in every Pediatr Adolesc Med 1996;150:70-3. 18 Eichenfield AH, Athreya BH, Doughty RA, Cebul RD. Util- case, there should be a low threshold for ity of rheumatoid factor in the diagnosis of juvenile performing an arthrocentesis. Doctors who rheumatoid arthritis. Pediatrics 1986;78:480-4. 19 Swissa M, Amital-Teplizki H, Haim N, Cohen Y, Shoenfeld would not hesitate to perform a lumbar punc- Y. Autoantibodies in neoplasia. An unresolved enigma. ture if they had even a mild suspicion that the Cancer 1990;65:2554-8.