Educational draft · awaiting clinical reviewUse Rapid for revision, not patient-care decisions. Check current national and local guidance and the BNF or BNFC before acting.
2 min synopsisUK scopeSources checked 27 Aug 2026Clinical review pending
!
Mesenteric, renal, cardiac or limb ischaemia
Severe abdominal pain, peritonism, gastrointestinal bleeding, malignant hypertension, myocardial injury, mononeuritis with rapid weakness or threatened limb indicates organ-threatening medium-artery disease.
Action: Admit, stabilise circulation and pressure, obtain CTA or catheter angiography and surgical or vascular input, test hepatitis B urgently, and start high-dose glucocorticoid plus cyclophosphamide for severe non-viral PAN after cultures and tissue planning.
Synopsis
Recognise polyarteritis nodosa as a medium-artery necrotising vasculitis causing renal, gastrointestinal, skin, nerve and testicular ischaemia, distinguish it from small-vessel ANCA disease, and coordinate angiographic, biopsy and hepatitis-directed treatment.
PAN is necrotising vasculitis of muscular medium and small arteries, producing renal-vascular, gastrointestinal, skin, nerve, muscle and testicular ischaemia without primary glomerulonephritis or pulmonary capillaritis.
Look for fever, weight loss, livedo, tender nodules, ulcers, myalgia, mononeuritis multiplex, severe hypertension, abdominal pain after meals, GI bleeding and testicular pain.
Urinalysis is often bland or shows non-glomerular abnormalities; red-cell casts or pulmonary haemorrhage should redirect toward AAV, anti-GBM or immune-complex disease.
Key red flags
Severe pain out of proportion, guarding, lactate rise or GI bleeding may indicate mesenteric infarction or perforation and requires immediate surgical and vascular imaging.
Mesenteric ischaemia
Postprandial or severe acute abdominal pain, bleeding and peritonism signals bowel arterial injury and possible infarction.
Investigation priorities
01
FBC, CRP or ESR, renal, liver, CK and urinalysisFirst step
Assess inflammation, ischaemic organ injury and whether urine suggests a small-vessel glomerulonephritis alternative.
Management branches
First-line confirmationDefine the medium-vessel phenotype
Painful skin, nerve, renal-vascular, bowel or testicular features suggest PAN.
Assess organ threat and map pulses, pressure, skin, nerve, abdominal and testicular findings, urine and cardiopulmonary absence or presence.
Test hepatitis and infection, obtain CTA or MRA of involved territories and select accessible deep tissue for biopsy.
Key medicines
Prednisolone for severe PANUse 1 mg/kg orally once daily, commonly up to 60 mg/day, after intravenous methylprednisolone 500 mg–1 g daily for three days when an organ is critically threatened; taper with remission induction.
Intravenous cyclophosphamideA specialist pulse course may give 15 mg/kg intravenously at baseline, after two weeks and after four weeks, then continue at three-week intervals with age-, kidney- and cytopenia-based reductions.
National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.