Condition

Immune deficiency

An immune deficiency means that part of the immune system does not work as expected, which can lead to infections that are frequent, severe or hard to clear. An allergist and immunologist can look at whether a pattern of infections needs further investigation.

Referral reasons

Common signs people are referred for

A doctor may refer you to an allergist if you or your child have:

  • Infections that keep coming back
  • Infections that are unusually severe or hard to clear
  • Frequent sinus or ear infections, or repeated pneumonia
  • Needing repeated or prolonged treatment for infections
  • Infections with unusual organisms, or slow growth in a child
  • A family history of immune deficiency

Most people get infections from time to time, and frequent infections do not mean an immune deficiency. These are reasons a doctor may suggest an immunology visit, not a way to diagnose yourself or your child.

The assessment

How an allergist assesses it

An evaluation begins with a careful look at the pattern of infections: what kind they were, how serious, how often and how well they responded to treatment. Your allergist will also ask about family history, because some immune conditions run in families. Records from hospital stays, cultures and earlier tests give important clues, and you or your doctor can bring them to the visit.

Depending on the situation, blood tests may look at blood-cell counts, immunoglobulin levels, antibody responses and other parts of the immune system. More testing may be suggested depending on the first results. A single abnormal result does not always mean an immune deficiency, so results are read together with your history. You can read more on our immune deficiency evaluation page.

Many people who are assessed turn out not to have an immune deficiency. In that case, your allergist can talk with you about other possible explanations for the infections and can share their findings with your own doctor.

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.

Care

Treatment and management options

What happens next depends entirely on what the evaluation finds. General categories include:

  • A clear explanation of the findings, including when no immune deficiency is found
  • Guidance on reducing the risk of infections and on when to seek care
  • Regular follow-up and monitoring
  • Treatments that your allergist and immunologist discuss with you if an immune deficiency is confirmed
  • Co-ordination with your family doctor and any other specialists involved in your care

Your allergist will explain each step and why it is being suggested.

All ages

Children and adults

Our pediatric and adult allergists see all ages. Immune conditions can appear in infancy, childhood or adult life, and children and adults can both be evaluated at the same clinic, in person or virtually.

Questions

Frequently asked questions

Does having frequent infections mean I have an immune deficiency?

No. There are many reasons someone may have repeated infections. The purpose of an immunology assessment is to see whether the pattern is unusual enough to need further investigation.

Are immune deficiencies inherited?

Some are inherited, while others develop because of another medical condition or treatment. Your allergist will ask about family history as part of the evaluation.

What tests are used?

Blood tests are common, and they may look at blood-cell counts, immunoglobulin levels and antibody responses. Your allergist decides which tests make sense based on your history.

Can children and adults both be assessed?

Yes. Our pediatric and adult allergists see patients of all ages, in person or through our virtual allergy clinic.

Next step

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 work

For physicians

Send a referral through our secure online form, or read the referral guide first.

Open the referral form

Current wait: 10 to 16 weeks after we receive the referral Updated October 2026

Last updated: October 2026Prepared by: Dandelion Allergy CentreGeneral information only, not medical advice. Your allergist's instructions take priority over anything on this page.