MSK

Question 1

Henoch Schonlein Purpura:
- Definition
- Pathophysiology
- Symptoms (4)
- Signs (3)
- Investigations
- DD (3)
- Manage
- Complications (3)
- Extra facts

Answer 1

Henoch Schonlein Purpura:

• Definition: IgA vasculitis around 3-15 years
• Pathophysiology: inflammation occurs in the affected organs due to IgA deposits in bv affecting skin, kidney, GI tract and joints. Characterised rash is caused by inflammation and leaking of blood from small bv under skin. Often triggered by URTI or gastroenteritis
• Symptoms: purpuric rash with erythematous macular wheals which evolves into ecchymoses petechiae + palpable purpura) affecting lower limbs + buttocks in children symmetrical distributed (if severe can ulcerate/necrosis), joint pain (arthalgia)/arthritis transient oligoarticular (1-4 joints) in large lower joints, abdo pain/N+V, renal involvement (haematuria/proteinuria +/- HTN due to IgA nephritis)
• Signs: palp rash under skin/ non blanching, reduced rom, proteinuria
• Investigations: bloods (fbc, blood film (no thrombocytopenia/sepsis/leukaemia), renal profile u+es, serum albumin for nephrotic syndrome, crp for sepsis, blood cultures), urine dip proteinuria, urine protein: creatinine ratio to see how much proteinuria, bp for htn
• DD: meningococcal sepsis (but has fever), leukaemia, idiopathic thrombocytopenic purpura
• Management: supportive, analgesia, rest, hydration, repeat urine dip for proteinuria/haematuria. Abdo pain lasts few days but renal involvement 4-6 weeks
• Complications: GI haemorrhage, intussusception, bowel infarction
• Extra facts: Diagnosis criteria in word document

Question 2

Septic arthritis:
- Definition
- Causes
- Risk factors (6)
- Symptoms (3)
- Signs (2)
- Investigations (3)
- Management
- Complications (3)
- DD (6)

Answer 2

Septic arthritis:

• Definition: infection of synovial fluid of joint. Most common in children <4
• Causes: haematological spread or direct via staph aures or haem influ and then abscesses form, neisseria gonorrhoea in sexually active teenagers
• Risk factors: immunocomp, trauma, previous, recent surgery, joint replacement, injections
• Symptoms: red hot swollen painful, not weight bearing
• Signs: fever, tachycardia, limited rom/stiff
• Investigations: joint aspiration and send for MC+S, bloods (fbc, crp, esr, blood culture), xray (joint space widening)
• Management: abx 3-6 weeks, splint, drain/washout
• Complications: OA, dislocation, osteomyelitis
• DD: transient synovitis (use kocher criteria to distinguish, includes can’t weight bear, pyrexia, elevated WCC/ESR and if >3 then likely septic arth), perthes disease, SUFE, juvenille idiopathic arthritis, osteomyelitis, reactive arthritis (following infection/urin symptoms/conjunctivitis)

For knee swellings if <6 hours assume haemarthrosis due to ACL rupture and if >6hrs reactive synovitis

Question 3

Reactive arthritis:
- Definition
- Risk factors (3)
- Causes (4)
- Symptoms (3)
- Investigations (4)
- Management
- DD

Answer 3

Reactive arthritis:

• Definition: Spondyloarthropathies are group of conditions due to HLAB27 gene. Reactive a is synovitis developing after infection days to 2 weeks. Also known as Reiters syndrome
• Risk factors: sexual contact, contaminated food, male
• Causes: salmonella, shigella, campylobacter, chlamydia
• Symptoms: can’t see (red, pain, blurry vision) (conjunctivitis, bilateral uveitis), can’t wee (burning, discharge, inc urine) (circinate balanitis, urethritis, keratoderma blennorrhagia), can’t climb up a tree (joint pain) (assymp lower limb arthritis of knees/ankles/feet, enthesitis)
• Investigations: aspirate for serology/microbiology (arthrocentesis), bloods (inc crp, esr), urine dip, xrays
• Management: abx, nsaids/joint injections, resolves in 1 year, if not dmards
• DD: septic arthritis, rheumatic fever