Antihistamines are medicines used to help with allergy symptoms. They can reduce itching, sneezing, a runny nose, watery eyes, and some skin reactions such as Hives. In first aid, they may help with mild symptoms, but they do not replace urgent treatment for Anaphylaxis.
What are antihistamines?
Antihistamines are medicines that block the effects of histamine. Histamine is one of the chemicals the body releases during an Allergic Reaction.
By blocking histamine, these medicines can help reduce some common allergy symptoms.
What symptoms can antihistamines help with?
Antihistamines may help with:
- itching
- sneezing
- a runny nose
- itchy or watery eyes
- mild skin rash
- Hives
They are commonly used for Pollen Allergy and other mild allergy symptoms.
Do antihistamines treat anaphylaxis?
No. Antihistamines do not treat the life-threatening airway and circulation problems seen in Anaphylaxis.
If someone has signs of anaphylaxis:
- use a prescribed Adrenaline Auto-Injector immediately if available
- if you know the brand, follow the correct steps for EpiPen or Anapen
- call
000in Australia - keep the person in a safe position and monitor breathing and response
The emergency medicine inside an adrenaline auto-injector is Epinephrine, not an antihistamine.
Are all antihistamines the same?
No. Different antihistamines can have different effects and side effects.
Some may cause drowsiness, while others are less likely to.
People should follow medical, pharmacy, or product guidance about which medicine is appropriate for them.
When are antihistamines useful in first aid?
Antihistamines may be useful for mild symptoms when the person is otherwise stable.
They are not the main treatment if the person has:
- trouble breathing
- throat swelling
- collapse
- severe allergy symptoms that suggest anaphylaxis
How is this page different from other allergy pages?
This page explains the medicine group.
- Pollen Allergy explains one common reason people take antihistamines
- Hives explains a common symptom they may help with
- Allergic Reaction explains the broader event
- Adrenaline Auto-Injector explains the emergency device pathway
- Anaphylaxis explains the life-threatening emergency where antihistamines are not enough
Summary
Antihistamines are medicines used to reduce allergy symptoms such as itching, sneezing, a runny nose, watery eyes, and hives. They can help with mild reactions, but they do not replace adrenaline for anaphylaxis. In first aid, the key step is to match the treatment to the seriousness of the reaction.
Sources reviewed
Reviewed against current Australian allergy, first aid and emergency guidance by the First Aid Glossary Editorial Team. This article is general information and does not replace a person’s current ASCIA Action Plan, device instructions, emergency-operator directions, professional medical advice or hands-on first aid training.
