The Histamine, Plasma test contains 1 test with 1 biomarker.
Description: The Histamine plasma test is used by physicians to help with identifying possible anaphylaxis, mastocytosis, or severe allergies if other test results are inconsistent.
Collection Method: Blood Draw
Specimen Type: Plasma
Test Preparation: Avoid taking allergy causing drugs, antihistamines, oral corticosteroids and substances which block H2 receptors 24 hours prior to collection.
When is a Histamine test ordered?
Histamine testing is not usually requested. Histamine or tryptase tests are typically not used to identify anaphylaxis, and mastocytosis is uncommon. When a person exhibits symptoms that could indicate anaphylaxis, histamine and tryptase tests may be requested, particularly if the diagnosis is hazy and/or the symptoms are persistent. Anaphylaxis symptoms include:
- breathing issues and wheeze
- Flushing
- Itching, frequently accompanied with hives,
- dizziness or lightheadedness
- reduced blood pressure
- throat, face, tongue, and/or eye swelling
- Several of these symptoms are also present in other diseases.
A doctor may also recommend testing if they believe a patient has mastocytosis or a condition involving mast cells. Many of the symptoms and signs shared by people with severe allergies are also present in people with these illnesses, but there is no known trigger, such as exposure to certain foods or bee stings. Peptic ulcers, persistent diarrhea, joint pain, enlargement of the liver, spleen, or lymph nodes, rashes, or the distinctive red, blistering lesions may appear singly or in large numbers in people with systemic mastocytosis.
What does a Histamine blood test check for?
When mast cells, specialized cells, are triggered, a chemical known as histamine is released, frequently as a result of an allergic immunological reaction. Histamine levels in the blood is determined by this test.
Large tissue cells called mast cells can be found all over the body. They are primarily found in the bone marrow, skin, and lining of the intestine and air passageways. Mast cells are a typical component of both the body's response to damage and allergy reactions. Histamine and tryptase, which are released when mast cells are triggered, are stored in granules that are found in them. Many allergy sufferers' symptoms are brought on by histamine.
Histamine levels in the blood and urine are typically quite low. Those who have a strong allergic reaction and those who have a disease in which the number of mast cells grows and/or activates without obvious sensitivities can both experience significant increases.
Anaphylaxis, a severe type of acute allergic reaction that can result in hives, skin reddening, low blood pressure, severely narrowed airways, and even death, is linked to the activation of numerous mast cells. Histamine levels in the blood rise quickly in anaphylaxis, peaking within 10 minutes of the onset of symptoms and returning to normal in between 30 and 60 minutes. Shortly after this increased production, histamine and its main metabolite, N-methylhistamine, are eliminated, which is reflected in the urine as well.
Mastocytosis patients may have chronically elevated levels of tryptase and histamine. This uncommon illness is characterized by aberrant mast cell proliferation, infiltration, and accumulation in the skin and/or other body organs.
Lab tests often ordered with a Histamine test:
- Tryptase
- N-Methylhistamine
- Allergy testing
Conditions where a Histamine test is recommended:
- Allergies
- Asthma
- Bone Marrow Disorders
How does my health care provider use a Histamine test?
The mast cell activation test with histamine is a helpful tool. The test may be used to support the diagnosis of mastocytosis, a rare category of illnesses defined by aberrant mast cell proliferation, or it may be used to support the confirmation of an anaphylactic reaction in a patient.
Although tryptase and a histamine test may be performed in conjunction to assist confirm anaphylaxis as the cause of someone's severe symptoms, anaphylaxis is often diagnosed clinically. This is particularly valid if the patient experiences recurrent episodes or if the diagnosis is unclear. As soon as symptoms appear, blood must be drawn for a blood histamine test.
To assist in the diagnosis of mastocytosis or mast cell activation disease, histamine testing may occasionally be requested in addition to a tryptase test. Often, cutaneous mastocytosis only results in skin issues. Anaphylaxis and its symptoms can occur in people who have mast cell activation disease or systemic mastocytosis.
What do my Histamine test results mean?
Strong evidence for the diagnosis of anaphylaxis is the presence of abnormally high histamine and/or tryptase levels in a patient exhibiting those symptoms.
Normal histamine readings could mean that the patient's symptoms have another underlying cause or that the sample wasn't taken at the appropriate time. Blood histamine levels rise quickly during anaphylaxis and can return to normal in 30 to 60 minutes. Results may be normal if a sample is drawn too late. The results of a tryptase test can be compared to the results of the histamine tests. Tryptase levels rise and fall more gradually than histamine levels, peaking within 1 to 2 hours after symptom development.
It is less likely that someone experienced anaphylaxis if the timing of sample collection was proper and neither the blood histamine nor tryptase concentration were increased. Even when the test came back negative, the diagnosis cannot be ruled out because a person can have anaphylaxis or mastocytosis without having raised histamine levels.
Elevated histamine and/or N-methylhistamine concentrations in a 24-hour urine sample signify a mast cell activation event. It is more likely that a person has mastocytosis if they have persistently high histamine and/or tryptase levels and this disease. Further testing is still required to confirm the diagnosis.
We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.
