Word parts
What it means
A messenger chemical stored mainly in mast cells and basophils. When an allergenAL-er-jenA substance that triggers an allergic reaction in a person whose immune system is sensitive to it.all/o other-gen something that producesFull entry or injury sets it free, it causes redness, itching, swelling, runny nose and narrowing of the airways. In the stomach it signals cells to make acid. Drugs that block it are antihistaminean-tee-HIS-tuh-meenA drug that blocks the effects of histamine, used mostly for allergy symptoms.anti- againsthistamine Full entry (H1 blockers) and acid-reducing H2 blockers such as famotidine.
For the nurse
A large, sudden release of histamine is part of anaphylaxisan-uh-fuh-LAK-sisA sudden, severe allergic reaction that affects the whole body.ana- away, against-phylaxis protectionFull entry . Watch for hives, wheezing, swelling of the lips or tongue and a falling blood pressure after a new drug, transfusion or food.
At a glance
| Spanish | histamina |
|---|---|
| Also written | histamines |
Related terms
anaphylaxis
A sudden, severe allergic reaction that affects the whole body.
antihistamine
A drug that blocks the effects of histamine, used mostly for allergy symptoms.
allergen
A substance that triggers an allergic reaction in a person whose immune system is sensitive to it.
allergic reaction
A harmful response of the immune system to a substance that is harmless to most people.