Inflammatory Conditions

Juvenile Idiopathic Arthritis (JIA)

This is a condition which causes arthritis in someone <16 years old and which lasts more than 6 weeks.

– Officially there are 7 subtypes of JIA, but the most common is oligoarticular

– If left untreated it lead to bony deformities, stunt growth and even delayed puberty

Oligoarticular

This is the most common subtype in which 4 of fewer joints are affected during the first 6 months of disease

Symptoms:

– Morning joint stiffness

– Joint pain and swelling (affected medium sized joints: knees, ankles, elbows)

– Stiffness which worsens after periods of rest

– Limp

– Can get anterior uveitis (hence children should have regular ophthalmology screening)

Tests:

– Inflammatory markers CRP, ESR –> can be raised, but are often normal initially

– ANA can be positive, rheumatoid factor can be positive or negative

Diagnosis:

– Age <16yrs

– Persistent joint swelling (>6 weeks)

– No evidence of infection/other cause

Management:

– Refer to paediatric rheumatology for specialist management, who have range of treatments:

– NSAIDS –> but help relieve symptoms during flares

– Joint steroid injections –> This can be used for oligoarticular disease

– Immunosuppressants (e.g., methotrexate) –> can be used in some patients who are refractory to treatment

Septic Arthritis

This is arthritis due to an infectious agent, usually bacterial which usually involves a single joint (monoarticular)

– It can destroy a joint in 24hours and can be fatal

– Organisms enter the joint from skin lesion or via haematogenous spread

– Risk factors include joint surgery, immunosuppression, diabetes, and pre-existing joint disease.

Causes:

S Aureus is the most common in children, N Gonorrhoea in young adults

Osteomyelitis

This is an infection of the marrow and bone, usually bacterial which usually occurs in children.

– Bacteria enter the bone from the blood infecting metaphysis (kids) and epiphysis (adults)

– Bacteria can infect any bone, but most commonly the femur and proximal tibia

Causes:

Staph Aureus (90%), N gonorrhoeae (sexually active adults), Salmonella typhi (in sickle cell)

Symptoms:

– Bone pain with systemic signs of infection (High WBC and fever)

– Limited range of motion in the limb, with severe pain on movement

– Swelling and redness over limb

Diagnosis:

– Blood culture

– MRI is the imaging of choice

Management:

IV antibiotics. If there is no response may require surgical aspiration or drainage

Reactive arthritis

This is a condition when arthritis occurs as an autoimmune reaction to infection elsewhere

– It is associated with HLA-B27 and is a type of seronegative arthritis (negative for rheumatoid factor)

– It is seen in young adults usually after a sexually transmitted infection, but also seen in children following gut infection

– This may be due to bacteria like Salmonella, Campylobacter, shigella

– Symptoms start around a moth after the initial infection and may last up to half a year

Symptoms:

– Gives a classic triad of arthritis, urethritis, and conjunctivitis (Can’t see, pee or climb a tree)

– Arthritis (asymmetrical joint pain of the lower limbs) with swelling, heat and restricted movement

– Can cause anterior uveitis

– Skin lesions –> vesicles on the margin of the foreskin called circinate balanitis

Diagnosis:

– Raised inflammatory markers ESR and CRP

– Evidence of previous infection

– X-ray is normal

Management:

– Symptomatic management with NSAIDs

– If symptoms continue for longer, then immunosuppressants can be considered

Growing pains

This refers to normal pains in growing children and is also known as nocturnal idiopathic pain

– It is poorly understood but is commonly seen in young children before their growth spurt in their teenage years

– It causes episodes of pain in the lower limbs and wakes the child from sleep and settles with massaging/comforting

Symptoms:

– Age 3-12 years

– Symmetrical pain in the lower limbs which is not limited to joints

– Pains never present when the child wakes up

– The pain should not limit physical activities (i.e., no limping)

– Physical examination should be normal (except for hypermobility in some)

Diagnosis:

It is a diagnosis of exclusion, once red flag symptoms have been ruled out

Management:

Reassurance as the pains are self-resolving