Table 4 Diseases which should be considered as differential diagnoses of mast cell activation disease, since they may mimick or may be associated with mast cell activation (diagnostic procedure of choice in parentheses).

Endocrinologic disorders

Diabetes mellitus (laboratory determination)

Pancreatic endocrine tumours (gastrinoma, insulinoma, glucagonoma, somatostatinoma, VIPoma; laboratory determination, medical history)

Porphyria (laboratory determination)

Disorders of the thyroid gland (laboratory determination)

Morbus Fabry (clinical picture, molecular genetic investigation)

Gastrointestinal disorders

Helicobacter-positive gastritis (gastroscopy, biopsy)

Infectious enteritis (stool examination)

Eosinophilic gastroenteritis (endoscopy, biopsy)

Parasitic infections (stool examination)

Inflammatory bowel disease (endoscopy, biopsy)

Celiac disease (endoscopy, biopsy, laboratory determination)

Primary lactose intolerance (molecular genetic investigation)

Microscopic colitis (endoscopy, biopsy)

Amyloidosis (endoscopy, biopsy)

Intestinal obstructions by adhesions, volvulus and other reasons (medical history, imaging methods, laparoscopy)

Hepatitis (laboratory determination)

Cholelithiasis (imaging methods)

Hereditary hyperbilirubinemia (laboratory determination)

Immunological/neoplastic diseases

Carcinoid tumour (medical history, laboratory determination)

Pheochromocytoma (medical history, laboratory determination)

Primary gastrointestinal allergy (medical history)

Hypereosinophilic syndrome (laboratory determination)

Hereditary angioedema (medical history, laboratory determination)

Vasculitis (medical history, laboratory determination)

Intestinal lymphoma (imaging methods)