15- Paediatric Orthopaedics and Rheumatology Flashcards
Reactive arthritis background
Inflammation and joint pain triggered by an infection in another part of the body
- GI
- Genitals
- Urinary tract
Reactive arthritis pathophysiology
Sterile synovitis developing after a distant infection
Post diarrheal/ dysentery
o Salmonella
o Shigella
o Campylobacter
Post urethritis/cervicitis (STI)
o Chlamydia trachomatis
presentation of reactive arthritis
- few days – 2 weeks post infection
- acute asymmetrical lower limb arthritis develops.
- Red eye
- Other features: skin (circinate balanitis, keratoderma blennorrhagica), eye (conjunctivitis, uveitis), enthesitis.
- Affected joints
o Knee
o Ankles
o feet
investigations for reactive arthritis
serology/microbiology, inflammatory markers raised, may need joint aspirate to rule out septic/crystal arthritis
management of reactive arthritis
- Treat infection (this may not improve arthritis).
- NSAIDs and joint injections.
- Most will resolve within 2 years.
- Those that do not (esp if HLA-B27+) may need DMARDs.
prognosis of reactive arthritis
Usually goes within 12 months
septic arthritis background
- Septic arthritis refers to infection inside a joint.
- This can occur at any age, but is most common in children under 4 years.
- Infection in a joint is an emergency, as the infection can quickly begin to destroy the joint and cause serious systemic illness.
- Septic arthritis has a mortality around 10%..
- Septic arthritis is a common and important complication of joint replacement.
o It occurs in around 1% of straight forward hip or knee replacements. This percentage is higher in revision surgery.
pathogenic cause of septic arthritis
- Staphylococcus aureus most common
Other: - Neisseria gonorrhoea (gonococcus) in sexually active teenagers
- Group A streptococcus (Streptococcus pyogenes)
- Haemophilus influenza
- Escherichia coli (E. coli)
presentation of septic arthritis
Septic arthritis usually only affects a single joint.
This is often a knee or hip. It presents with a rapid onset of:
- Hot, red, swollen and painful joint
- Refusing to weight bear
- Stiffness and reduced range of motion
- Systemic symptoms such as fever, lethargy and sepsis
Septic arthritis can be subtle in young children, so always consider it as a differential when a child is presenting with joint problems.
investigations of septic arthritis
- X-ray of joint
- Joint aspiration
o Gram staining, crystal microscopy, culture and antibiotics sensitivities
management of septic arthritis
- Empirical IV antibiotics (given until sensitivity are known)
- Long term abx for 3-6 weeks
- May require surgical drainage and washout of the joint to clear the infection
management of septic arthritis
- Empirical IV antibiotics (given until sensitivity are known)
- Long term abx for 3-6 weeks
- May require surgical drainage and washout of the joint to clear the infection
what sort of disease is Henoch-schonlein purpura (HSP)
IgA vasculitis (IgAV)
background Henoch-Schonlein Purpura
- IgA vasculitis (IgAV)
- Palpable purpura without thrombocytopenia
- Most common form of systemic vasculitis in children,
- Unknown cause: 50% develop after URTI
- Peak age 3- 15 years
- Clinical manifestations develop over days and weeks- rash and arthralgia first
pathophysiology of HSP
- Inflammation occurs in affected organs due to IgA deposits in blood vessels
- Rash is caused by inflammation and leaking of blood from small blood vessels under the skin-> purpura
presentation of HSP
- skin
- arthritis/anthralgia
- GI
- kidney
HSP skin
THINK LOWER LIMBS- GRAVITY
Palpable purpura in the lower limbs and buttocks with neither thrombocytopenia or coagulopathy.
- Rash often begins with erythematous, macular wheals – may be itchy; rarely painful.
- Evolves into typical ecchymoses, petechiae and palpable purpura; typically in crops.
- Symmetrically distributed, located in gravity/pressure dependent areas e.g. lower extremities.
HSP: arthritis
- Common (affecting up to 80%) but rarely presents as sole symptom
- Usually transient, oligoarticular (1-4 joints), non-deforming in large lower extremity joints.
HSP: GI
abdominal pain
- affects about 50%
Severity varies:
- from mild: nausea, vomiting, abdominal pain, paralytic ileus.
- to severe: GI haemorrhage, ischaemia, necrosis, intussusception , perforation
HSP: Kidney
o IgA nephritis affects about 20-50%
o Haematuria (most commonly), proteinuria, elevated creatinine ± hypertension.
Investigations for HSP
Exclude serious pathology
- Meningococcal septicaemia
- Leukaemia
Bloods
- FBC
- Blood film for thrombocytopenia
- CRP
- Renal profile (U and E)
- Serum albumin (nephrotic syndrome)
- Blood culture for sepsis
Urine dipstick for proteinuria
- Urine protein: creatinine ratio
BP for hypertension
diagnosis of HSP
Diagnosis: EULAR/PRINTO/PRES criteria from 2010. This requires the patient to have palpable purpura (not petichiae) + at least one of:
* Diffuse abdominal pain
* Arthritis or arthralgia
* IgA deposits on histology (biopsy)
* Proteinuria or haematuria
management of HSP
- Supportive management: analgesia, rest and proper hydration
- +- steroids (debatable
- Monitor closely
o Urine dipstick for renal involvement
o Blood pressure to monitor HTN
prognosis for HSP
Prognosis
- Abdominal pain resolves within days
- Kidneys recover within 4 to 6 weeks
- 1/3 have recurrence iwithin 6 months
- Some will develop end stage renal failure
osteosarcoma background
- Bone cancer
- Usually presents in adolescents and younger adults
->10-20yo - Femur most commonly affected
-> Tibia
-> Humerus - Types- depending on how well-differentiated the cells are when oncogenic events occur
-> Osteoblastic- most highly differentiated
->Chrondroblastic
-> Fibroblastic- least highly differentiated
Risk factors for osteosarcoma
- Usually tall for age
- Males
- Li-Fraumeni syndrome
- RB1 mutation
- Prior radiation therapy
- Pagets/ osteochondromas
Risk factors for osteosarcoma
- Usually tall for age
- Males
- Li-Fraumeni syndrome
- RB1 mutation
- Prior radiation therapy
- Pagets/ osteochondromas
pathophysiology of osteosarcoma
Mutation occurs in rapidly dividing osteoblasts e.g. pubertal growth spurt
presentation of osteosarcoma
- Persistent bone pain
- Worse at night
- May wake them up
- Others:
-> Bone swelling
-> Palpable mass
-> Restricted joint movement - Weight loss, fatigue, headache