Diagnosis of ARF in children

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Speakers

November 2012

Alan Ruben FRACP, FAFPHMPaediatrician and Public Health Physician, Apunipima Cape York Health Council, Cairns and Hinterland Health Service District, Queensland Health.

Alan is a paediatrician and public health physician who has worked in Aboriginal health for over 20 years.

Ben Reeves MBBS, FRACPPaediatric cardiologist, Cairns and Hinterland Health Service District, Queensland Health.

Ben is a paediatric cardiologist based in Cairns, providing outreach paediatric cardiology services to Cape York and the Torres Strait.

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Learning objectives

November 2012

• Appreciate the pathway to ARF and then RHD

• Recognize who is at risk for ARF/RHD

• Understand the Jones criteria used for diagnosis

• Present the recommended investigations

• Outline current management guidelines

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Take home messages

November 2012

• Incidence in Aboriginal Australians and Torres Strait Islander people amongst the highest in the world

• Predominantly affects children aged 5 to 15

• Largely affects disadvantaged populations

• High index of suspicion in high risk populations

• Diagnosis needs clinical criteria and investigation results

• Diagnosis often requires hospital admission

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Abbreviations

November 2012

AR aortic regurgitation

ARF acute rheumatic fever

BPG benzathine penicillin G

CRP C-reactive protein

ESR erythrocyte sedimentation rate

GAS group A beta-haemolytic streptococcus

MR mitral regurgitation

RHD rheumatic heart disease

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More information – Guidelines

www.rhdaustralia.org.au

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More information – Quick reference

November 2012

www.rhdaustralia.org.au

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More information – other modules

November 2012

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ARF: some basics

• 3-6% of any population susceptible

• Incidence and prevalence in females >males

• ARF/RHD can run in families

• Specific genetic markers have been identified

• There is no racial predisposition

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• Amongst the highest rates in the world

• ARF commonest in remote and disadvantaged areas

• Some Australian medical staff unfamiliar with ARF

Australian setting

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Environment

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Risk factors

• Established clear link with poverty

- household overcrowding

- poor sanitation

- housing quality and appropriateness

- educational disadvantage

• Limited access to health services

- variability of health infrastructure and follow up

• Geographically remote

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GAS pharyngitis

Arthritis

Carditis

Chorea

Fever

Exaggerated immune response

Acute rheumatic fever – ARF

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ARF recurs - often many times

Valve damage is cumulative and silent

Rheumatic heart disease (RHD)

Cardiac failure, early death

*

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ARF progression

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Jones criteria

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Diagnosis and GAS

• Definite initial or recurrent ARF diagnosis requires:

• 2 major plus evidence GAS infection

• 1 major plus 2 minor plus evidence of GAS infection- Throat swab- ASOT

- Anti DNAse B

• No other probable diagnosis

November 2012

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Major manifestations

November 2012

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Major manifestations

High risk groups

Polyarthritis or aseptic mono-arthritis or polyarthralgia

Carditis (including subclinical evidence of rheumatic valvulitis on echocardiogram)

Chorea

Erythema marginatum

Subcutaneous nodules

Low Risk groups

Polyarthritis

Carditis

Erythema marginatum

Subcutaneous nodules

Chorea

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• Monoarthritis present in 17% of ARF presentations

• Migratory asymmetric polyarthritis

• Affects peripheral large joints

• Often intense pain – will not tolerate passive movement

• Limited duration: 2 days to 3 weeks

• Dramatic response to salicylates

- rapid response assists diagnosis

Arthritis

November 2012

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Can a monarthritis be ARF?

• In high risk populations:

- aseptic monoarthritis can be a major manifestation

- monoarthritis often associated with carditis

- if joint aspirate sterile, prior to treatment for septic arthritis, investigate for ARF

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Polyarthralgia

• A major criteria ONLY in high risk populations:

- Multiple painful joints

- Can be migratory

- Unlike arthritis lacks:

o Effusions

o Heat

o Morning stiffness

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Carditis

• Can involve all layers of the heart

- Pericardium – can cause effusions

- Myocardium – affects heart function and conduction

- Endocardium – the classic valve lesions

• MR then AR most common lesions

• Right sided valves rarely involved

• Stenosis is a late finding

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Carditis: investigations

• Early echocardiography essential

- repeated at 2 to 6 weeks

• Chest x-ray

• Electrocardiogram

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Carditis: treatment

• Often requires inpatient bed rest and care if :

- moderate/severe carditis suspected by clinical findings

• Consider steroids for severe carditis

• If signs of heart failure or cardiomegaly

- consider diuretics and ACE inhibitors

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Sydenham’s chorea

• Rapid, uncoordinated jerking movements

• Primarily the face, feet and hands

• Female to male ratio of 2:1

• Occurs up to 6 months after acute infection

• Mostly children, 5 to 13 years

• “Milkmaids” sign

• Tongue fasciculations

• Emotional lability

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Erythema marginatum

• Rare finding- reported in less than 2% Australian Aboriginals- difficult to see on dark skin

• Presence of rash diagnostic of ARF

• Pale center and darker margins

• Blanch under pressure

• Circular snake like pattern

• Occurs on trunk and extremities

• Not itchy or painful

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Subcutaneous nodules

• Rare, only seen in 2% cases

• Highly specific of ARF

• Strongly associated with carditis

• Round firm and freely mobile

• 0.5 to 2.0 cm in diameter

• Appear 1 to 2 weeks after symptom onset

• Occur in crops of up to 12

- over elbows knees, wrists, ankles, achilles tendons, occiput, and posterior spinal processes

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Minor manifestations

High risk groups

Monoarthralgia

Fever

ESR≥30 mm/h or CRP ≥30 mg/L

ECG changes

Low Risk groups

Fever

ESR≥30 mm/h or CRP ≥30 mg/L

ECG changes

Polyarthralgia or aseptic monoarthritis

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Fever

• Temperature greater than 38C

• In the absence of fever documentation

- reliable history if anti-inflammatory therapy given

already given

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ESR & CRP

• Repeat serology 10 to 14 days if not confirmatory

• To satisfy minor criteria:

- serum CRP ≥30mg/L

- ESR ≥30mm/hr

• Elevated WBC insensitive marker for ARF

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ECG

• If ARF suspected always ECG

• Check P-R interval

• Normal 0.16 sec if 3 to 12 years old

• If prolonged

- repeat ECG in 1 to 2 months

• If P-R interval returns to normal:

- ARF more likely

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Diagnosis: key investigations

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Differential diagnosis

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Diagnosis key points

• ARF remains a difficult diagnosis

- requires recommended tests to be performed

• High index of suspicion for populations at greatest risk

• Cardiology opinion recommended for suspected ARF

• In high risk populations also consider ARF if:

- child < 5 years of age presents with arthritis

• Monoarthritis is a common presentation

• Simple falls rarely cause joint effusions

• Hospital admission recommended for initial presentations

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Probable ARF

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ARF diagnosis and management

• First requires diagnosis then secondary prophylaxis

• Inpatient assessment recommended

• Specialist review for ongoing management

• Bed rest

• NSAIDs

• Initial then follow up echocardiography

• Chest x-ray

• If heart failure: ACE inhibitors, diuretics

• Consider steroids for carditis

November 2012

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Principles of secondary prevention

November 2012

• Secondary prevention first requires the diagnosis of ARF/RHD

• Long term antimicrobial prophylaxis prevents recurrent ARF

- but significant challenges in service delivery

• Success requires:

- register-based program

- effective recall system

- functioning primary health care service

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Take home messages

• Incidence in Aboriginal Australians and Torres Strait Islander people amongst the highest in the world

• Predominantly affects children aged 5 to 15

• Largely affects disadvantaged populations

• High index of suspicion in high risk populations

• Diagnosis needs clinical criteria and investigation results

• Diagnosis often requires hospital admission

November 2012

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More?

November 2012

November 2012

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November 2012

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Diagnosis of ARF in children