Dandelion Drug and insect venom allergies
A drug allergy is an immune reaction to a medication, and an insect venom allergy is a reaction to the sting of an insect such as a wasp, hornet or bee. An allergist can review what happened, help work out whether you are truly allergic and advise on what to avoid.
Common signs people are referred for
A doctor may refer you to an allergist if you or your child have:
- A rash, hives, swelling or breathing trouble after taking a medication
- A drug allergy label from childhood and no clear memory of what happened
- An allergy label that is limiting which treatments your doctors can use
- Hives, widespread swelling, dizziness or breathing symptoms after an insect sting
- A large, swollen reaction at the site of a sting or bite
- Needing a medication but being worried because of a past reaction
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
For both kinds of allergy, the history is the most important part. For a medication, your allergist will ask which one was taken, when, what happened and how long the symptoms lasted. Old records and photos can help. For a sting, they will ask about the insect, where it happened and what symptoms followed.
Some people who were told they are allergic to a medication are later found not to be, but this can only be decided after careful assessment. Depending on your history, your allergist may use skin testing and may then suggest a supervised drug provocation test, in which a medication is given in clinic under close observation. This is not suitable for every type of past reaction, and your allergist will decide whether testing is safe. For insect stings, skin testing or blood tests may help. A positive test alone does not confirm an allergy, so results are read together with your history. Allergy skin testing is described on its own page.
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
Management depends on what the assessment finds. General categories include:
- Avoiding a medication that is confirmed to be a problem, with your allergy record kept up to date for all of your doctors
- Updating or removing an allergy label when testing shows it no longer applies, with guidance on what you can use in future
- Practical advice for reducing the chance of stings when an insect allergy is confirmed
- An emergency plan and, where it is prescribed, an epinephrine auto-injector. See anaphylaxis management
- Longer-term treatment for insect venom allergy, which your allergist may discuss if it applies to you
Your allergist will explain which of these apply to you.
When to seek emergency care
Swelling of the throat or tongue, trouble breathing, widespread hives, dizziness or fainting after a medication or an insect sting can be signs of a severe reaction. Call 911. If an epinephrine auto-injector has been prescribed, use it as you have been instructed.
Children and adults
Our pediatric and adult allergists see all ages. Children who were labelled with a medication allergy early in life and adults who have never had that label checked can both be assessed at the same clinic.
Frequently asked questions
Does a rash after a medication mean I am allergic?
Not necessarily. Rashes can have several causes, including the illness being treated. Your allergist can review what happened and decide whether further assessment is needed.
Can a drug allergy label be removed?
Sometimes. After a careful review, and when it is judged to be safe, your allergist may suggest supervised testing. If it is completed without a reaction, your allergist can explain what you may use in the future.
Is a large swelling at a sting site the same as anaphylaxis?
No. A large local swelling stays near the sting, while anaphylaxis affects the whole body. Throat swelling, trouble breathing or faintness after a sting need emergency care, and your allergist can explain the difference.
Will I need testing for insect stings?
That depends on your history. Your allergist will decide after hearing what happened and will explain what testing, if any, would help.
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.