Screening tests

USS

MRCP

Hepatitis screen

Calcium and PTH

Lipid screen

Autoimmune antibodies (PAN, SLE, vasculitis) – ESR, ANA, pANCA, cANCA

IgG4

Drug/medication history

Enquire about IBD symptoms, Trauma

Sphincter manometry

Aetiologies:

Obstructive pathologies: biliary disease, pancreatic duct strictures (inc choledochal cyst and pancreatic divisum), tumours of ampulla or pancreas

Toxic factors: alcohol (normally males consuming >80g alcohol per day, but no definite dose dependent relationship), viral infection (esp mumps, coxsackie B and viral hepatitis)- look for prodromal diarrhoea

Metabolic factors: hyperparathyroidism, hyperlipoproteinaemia, hypertriglyeridaemia

Genetic factors: defects of the cationic trypsinogen gene (N29I, RII7H) and cystic fibrosis gene (CTFR) may be associated with recurrent episodes

Trauma: blunt trauma causes hyperamylasaemia

Iatrogenic causes: ERCP (3%) with sphincterotomy, drug-induced (valproic acid, azathioprine, L-asparaginase, corticosteroids)

Inflammatory: autoimmune (IgG4) causes homogenous enlargement on CT, often associated with extrahepatic tree resembling sclerosing cholangitis, responds well to steroids. Also associations with plyarteritis nodosa, SLE, vasculitis and IBD (Crohn’s and UC). 

Physiological: Type  1 pancreatic sphincter dysfunction may be associated with hyperamylasaemia, diagnosed as abnormal sphincter manometry and treated by sphincterotomy (but risk of post-ERCP pancreatitis in these patients is v high at 30%)