Diagnosing these disorders is often a long, complicated process involving many areas of specialty medicine.  Many patients suffer declining health for up to 10 years or longer before finally being diagnosed.

Mastocytosis has a set of standard diagnostic testing.  Those with skin or hematological involvement seem to have the best chance of their physicians diagnosing their illness.  MCAS and Idiopathic Anaphylaxis involve many tests, most of which may be inconclusive.

None of the current diagnostic tests are reliable for every patient.  Some of these tests often return false-negatives.  Some tests return positive results outside the normal range, yet the patient experiences few symptoms and enjoys a normal unrestricted life.  Many patients have completely normal test results (eg. tryptase, urine, bone marrow) yet they are disabled by these disorders.  The largest discrepancy is reported by patients who test positive for a cutaneous form of Mastocytosis, yet negative test results proving systemic involvement, even though the patients exhibit all the classic symptoms of Systemic Mastocytosis.  Physicians and patients worldwide are aware of this.

Current diagnostic testing needs refinement and new tests need to be discovered that are more reliable and definitive for these disorders.  Researchers worldwide are constantly working to address these issues.

Listed below are the initial standard diagnostic tests. Some are less reliable than others and many are difficult to get access to in Canada.  These tests are used to determine the likelihood that a patient has Mastocytosis, MCAS or IA, or perhaps determine if it's something else entirely:

• Skin biopsy if spots, rash appearance or other skin involvement appears (*Wright Giemsa Staining of sample is required)
• Serum Tryptase blood test (baseline and then again within 2 hours of anaphylaxis where applicable)
• Bone Marrow aspiration and biopsy for presence of mast cells and to test tryptase.  Also identify CD25 expression, spindle shaped mast cells and abnormal morphology (*Wright Giemsa Staining of sample is required)
• Bone density test; Bone scintigraphy*(precautions needed for radiographic dyes with patients)
• Check for C-kit D816V mutation and/or JAK2 mutation V617F in bone marrow sample
• 24 Hour N-Methylhistamine Urine test (*specific sample preserve required) (**Not done in Canada, ship sample to Mayo Clinic or other in USA)
• Allergy tests (only if history directs it and there are foods where the timing of reactions is consistent with true allergic reaction)
• Prostaglandin D2 (PGD2) and 11 Beta-Prostaglandin F2 Alpha, Urine (BPG2) (*sample testing not done in Canada, ship samples to Mayo Clinic or other in USA)

Additional tests that may be considered include:

• Histamine and Heparin tests
Complete Blood Count & Chemistry Panel tests with specific attention on the following:
• Liver function
• Electrolytes
• Glucose
• Lipid panel
• Vitamin levels - Especially: Calcium, D, B12, Iron & Ferritin
• Red and White blood cell counts
• Immunoglobulins (IgE,IgA,etc.)
• ANA (Antinuclear antibodies)
• Erythrocyte Sedimentation Rate
• C-Reactive Protein
• Serotonin
• Chromogranin A
• Pulmonary function tests
• Ultrasound, X-ray, CT scan and/or MRI of abdomen, liver, spleen, brain
• Celiac test
• Adrenal function test
• Thyroid function tests (TSH, T3 and T4)
• 5-HIAA Urine test
• EKG
• Stress tests
• Upper GI Endoscopy
• Colonoscopy
• Vision/Eye exams - including imaging of eyes