Adults
Polyarteritis nodosa (PAN)
Medium-vessel vasculitis with tender nodules, livedo, mononeuritis multiplex or testicular or abdominal pain.
What to look for
- Tender skin nodules, livedo racemosa, ulcers
- Mononeuritis multiplex, testicular pain, hypertension, renal infarcts
- Post-prandial abdominal pain from mesenteric involvement
- Associated with hepatitis B in some patients. ANCA is typically negative.
What to do
- Send ESR, CRP, CBC, metabolic panel, urinalysis, hepatitis B and C serology and ANCA (to exclude ANCA vasculitis).
- Biopsy of an affected tissue, or angiography showing microaneurysms, supports the diagnosis.
- Mesenteric ischemia is emergent. Consider DADA2 testing (ADA2 deficiency) in young-onset or stroke-associated PAN.
About this urgency level
Early specialist assessment changes outcomes. Send the usual workup with the referral, but don't hold the referral while waiting for results.
Timeframes are typical targets. Local pathways, capacity and clinical judgment come first.