The acutely swollen joint

PIC Endorsed

Key points

There are many causes of an acutely swollen joint. The aim of initial assessment is to identify and treat serious ones
Acute inability to walk or weight bear is a red flag
Septic arthritis is an orthopaedic emergency and should be suspected in any child presenting with localised severe joint pain and swelling, especially with fever
Children discharged with an unclear diagnosis require early follow up

Background

Joint swelling is a common feature in many conditions that affect children
History, examination, and tailored investigations will help to differentiate serious from benign causes
In a child who is limping or non-weight bearing without a swollen joint please see The limping or non-weight bearing child

Assessment

History

Joint swelling: site, onset (<2 weeks is acute), character (migratory/early morning)
Fever
Functional limitation eg refusal to weight bear, or use affected joint
Constant severe pain or night pain
Trauma/injury
Systemic features: Weight loss/fatigue/night sweats, rash, unexplained bruising, visual impairment, diarrhoea
Recent illness
Family history: haemophilia, autoimmune or inflammatory conditions
Medication
At risk sexual behaviour/intravenous drug use
Groups at risk for acute rheumatic fever (ARF): Indigenous Australians, Maori and Pacific Islanders; personal or family history of ARF or rheumatic heart disease

Examination

Fever
Joint and limb assessment using the “Look, feel, move”, start with non-painful side
- Look: bruising/erythema/muscle wasting
- Feel: warmth, tenderness, also palpate tendons (enthesitis), and muscles and contiguous limbs
- Move: caution if severe pain
  - active: facilitate by placing toy or parent out of reach
  - passive: assess for limitations and asymmetry
- General musculoskeletal/functional/neurological and gait assessment
Haematological: Pallor, lymphadenopathy, petechiae/ecchymosis/purpura
Abdominal: Hepatosplenomegaly, abdominal mass
Skin: Rash/ bruising/hyperextensibility
Cardiac: cardiomegaly, thrill, pericardial rub, murmur
Eye: Red eye, decreased visual acuity, restriction in extraocular movement

Common differential diagnoses

Category	Condition	Clinical features
Infection	Septic arthritis/ Osteomyelitis	Severe localised joint and/or limb pain Systemic features, fever (acute onset) Commonly lower limb joints
Infection	Viral arthritis eg Enterovirus/Hepatitis B/Parvovirus/ Dengue	Cough, fever, rash At risk sexual/drug taking behaviour High risk contact of identified case Travel history to endemic area
Trauma	Fracture/dislocation/soft tissue injury	History of injury
Trauma	Child abuse	Unexplained injury, bruising Particularly if non ambulatory child
Reactive	Reactive arthritis	Recent illness: pharyngitis, gastroenteritis, urethritis (Chlamydia) Onset 7 to 14 days later Oligo/monoarticular arthritis, normally lower limbs
Haematological	Haemophilia	Personal/Family history Unexplained bruising/bleeding Most commonly knee
Rheumatological	Juvenile idiopathic arthritis/mixed connective tissue disease	Fever, rash Oligo/polyarticular arthritis Enthesitis Psoriasis Haematuria Hepatosplenomegaly Normally can weight bear
Other systemic inflammatory disorders	Kawasaki disease	Prolonged fever >5 days Rash, conjunctivitis, cervical lymphadenopathy, swelling of hands and feet
Other systemic inflammatory disorders	Acute rhematic fever (ARF)	At risk population Fever Migratory polyarthritis/arthralgia – usually large joints Heart murmur (mitral or aortic regurgitation) Skin changes (erythema marginatum/subcutaneous nodules) – seen rarely
Vasculitis	Henoch-Schönlein purpura	Purpuric rash (normally affecting lower limbs) Usually lower limb joints affected Preceding upper respiratory joint infection
Hypersensitivity	Serum sickness/ Serum sickness like reactions	Recent medication use Urticarial type rash, but can also present with papular or purpuric rash Polyarthritis
Malignancy	Leukaemia Bone/soft tissue malignancy/ Solid organ tumour	Fever, weight loss, lethargy, fatigue, anorexia, night sweats, Nocturnal pain Pallor, bruising Hepatosplenomegaly/abdominal mass
Endocrine	Rickets	Maternal vitamin D deficiency At risk for vitamin D deficiency (poor sunlight exposure/dark skin, predisposing medical conditions) Genu varum/valgus, widened wrists/ankles
Inflammatory bowel disease	Ulcerative colitis Crohn’s disease	Fever, diarrhoea, weight loss, uveitis, abdominal pain Hepatomegaly
Hypermobility	Ehlers-Danlos, other	Repetitive injury, recurrent subluxation/dislocation Fatigue, chronic pain Easy bruising/scarring of skin Joint laxity, hyperextensible skin

Management

Investigations

Consider no investigations if:
- No red flags
- A clear working diagnosis and/or a plan to review within 7 days
Investigations will be guided by the clinical features – with suggestions summarised in the flow chart below

Suggested diagnostic approach to acute joint swelling based on clinical features

Treatment

Definitive management is determined by the working diagnosis
Pain management: see acute pain management and consider immobilization
Child-directed limitation of activity
Septic arthritis is an orthopaedic emergency - consult local orthopaedic team
For infective causes, refer to the appropriate sub-specialist team and consult local antibiotic guidelines
Acute rheumatic fever:
- All suspected cases should be discussed with a paediatrician experienced in ARF, ID physician or paediatric cardiologist
- An echocardiogram is required even if no clinical murmur to exclude subclinical carditis
- Avoid NSAIDS during diagnostic workup, as these may mask migratory joint symptoms

Consider consultation with local paediatric team when

Suspected child abuse
Diagnosis is unclear

Refer for specialist assessment if:

Suspected septic arthritis (orthopaedics)
Suspected haemarthrosis in a known or suspected haemophiliac (haematology)
Joint pain >4 weeks and/or multiple joints involved, or vasculitis other than HSP (rheumatology)

Consider transfer when

The child requires care above the level of comfort of the local hospital

For advice about acutely unwell transfers requiring PICU or neonatal retrievals see Retrieval Services

Consider discharge when

The cause of the swollen joint has been identified and appropriately managed
If the diagnosis is unclear:

The child’s pain is adequately managed AND
High risk diagnoses have been considered and excluded AND
Appropriate follow up has been arranged

Parent information

Pain relief for children - paracetamol and ibuprofen

Last updated October 2021

Reference List

Balan S. Approach to Joint Pain in Children. Indian Journal of Pediatrics. 2016;83(2):135-139. doi:10.1007/s12098-015-2016-8

Kimura Y, Southwood TR. Evaluation of the child with joint pain and/or swelling. UpToDate. https://www-uptodate-com.www.ezpdhcs.nt.gov.au/contents/evaluation-of-the-child-with-joint-pain-and-or-swelling?search=swollen%20joint&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1 (Accessed February 21, 2021).

Nannery R, Heinz P. Approach to Joint Pain in Children. Paediatric and Child Health. 2018 Feb;28(2):43-49.

RHDAustralia (ARF/RHD writing group). The 2020 Australian guideline for prevention, diagnosis and management of acute rheumatic fever and rheumatic heart disease (3rd edition); 2020

Vardiabasis NV, Schlechter JA. Definitive Diagnosis of Children Presenting to A Pediatric Emergency Department With Fever and Extremity Pain. J Emerg Med. 2017 Sep;53(3):306-312. doi: 10.1016/j.jemermed.2017.05.030. PMID: 28992868.

Starship Hospital Guidelines. Limp – assessment of paediatric limp in the Emergency Department. Published 25 August 2020.

The Royal Children's Hospital Melbourne

Clinical Practice Guidelines