Dandelion Anaphylaxis
Anaphylaxis is a sudden and serious allergic reaction that can affect breathing, circulation and several parts of the body at once. An allergist can help find out what caused a reaction, review your risk and put a written emergency plan in place.
Common signs people are referred for
A doctor may refer you to an allergist if you or your child have:
- A past reaction with trouble breathing, throat tightness or faintness after a food, medication or insect sting
- A reaction that involved more than one part of the body, such as hives together with vomiting or breathing symptoms
- A reaction that needed epinephrine or an emergency department visit
- A serious reaction with no obvious trigger
- A reaction after exercise, or only when exercise and a meal happen together
- Not feeling confident about when or how to use an epinephrine auto-injector
These are reasons a doctor may suggest an allergist visit. They are not a way to diagnose yourself or your child.
How an allergist assesses it
The most important part of the assessment is a detailed account of the reaction: what happened before it, which symptoms appeared and in what order, how quickly they developed, what treatment was given and how you recovered. Anaphylaxis can happen without hives, so skin symptoms do not need to be present. Medical records and photos from the time can help.
Depending on the story, your allergist may use allergy skin testing or blood tests to look at suspected triggers. A positive test alone does not confirm the cause of a reaction, and a negative test does not always rule one out, so results are always read together with your history. A supervised oral food challenge or drug allergy testing is used only when the allergist judges that it is safe.
Your clinic will tell you before the visit what, if anything, needs to be paused. Please do not pause any medication unless the clinic or your own doctor has told you to.
Treatment and management options
Anaphylaxis care focuses on understanding the trigger and being prepared. Your allergist will talk with you about:
- Avoiding confirmed triggers, and practical steps for school, work, travel and restaurants
- An epinephrine auto-injector where it is prescribed, with training on when and how to use it
- A written emergency action plan that family members, teachers and caregivers can follow. See anaphylaxis management
- Understanding that antihistamines and asthma inhalers do not replace epinephrine in anaphylaxis
- Treatment aimed at the trigger where this is appropriate, such as food allergy immunotherapy for some patients
Our patient resources include short technique videos for epinephrine auto-injectors on the resources page.
When to seek emergency care
If you or someone else may be having anaphylaxis, such as trouble breathing, swelling of the throat or tongue, a hoarse voice, widespread hives, repeated vomiting, dizziness or fainting, use an epinephrine auto-injector if one has been prescribed, as you have been instructed, and call 911. Do not wait to see whether symptoms get worse. Anyone who has used epinephrine still needs to be assessed in an emergency department.
Children and adults
Our pediatric and adult allergists see all ages. We can help parents and caregivers prepare for school and camp, and help teens and adults plan for their own day-to-day lives.
Frequently asked questions
Can anaphylaxis happen without hives?
Yes. Hives are common but not required. Trouble breathing, throat tightness, dizziness or faintness after exposure to a known or suspected trigger can be anaphylaxis even if the skin looks normal.
Do antihistamines replace epinephrine?
No. Antihistamines may help with itching and hives, but they do not treat the dangerous breathing and blood pressure problems of anaphylaxis. Your allergist will explain your emergency plan.
Why do I still need medical care after using epinephrine?
Symptoms can return after the first dose wears off, and some people need further treatment. Anyone who has had a suspected anaphylactic reaction should call 911 and be assessed in an emergency department.
How do I get an anaphylaxis assessment?
Patients cannot refer themselves. Ask your family doctor or a walk-in clinic to fax a referral to 416 850 9993, and our team will contact you to book.
Related reading
Getting an assessment
For patients
Patients cannot refer themselves. Ask your family doctor or a walk-in clinic to fax a referral to 416 850 9993, and our team will contact you to book.
How referrals workFor physicians
Send a referral through our secure online form, or read the referral guide first.
Open the referral formLast updated: October 2026Prepared by: Dandelion Allergy CentreGeneral information only, not medical advice. Your allergist's instructions take priority over anything on this page.