Selective Deficiency of IgA: Causes, Symptoms, and Treatment
Medically reviewed by Harsha Moole, MD, Internal Medicine. Last reviewed: October 2, 2026.
What kind of doctor treats Selective Deficiency of IgA?
A primary care doctor usually manages selective IgA deficiency. If infections are frequent or severe, they may refer the patient to an immunologist, a specialist in immune system problems. A direct primary care or concierge doctor can be a first stop for an evaluation and can refer you to a specialist when needed.
What it is
Selective IgA deficiency is a condition where the body makes very little or none of a protein called immunoglobulin A, or IgA. IgA is an antibody, a protein the immune system uses to fight germs. It normally protects moist surfaces like the nose, throat, lungs, and intestines. Many people with this condition feel fine and never know they have it, while others get more ear, sinus, lung, or gut infections than usual.
Symptoms
Some people have no symptoms at all. When symptoms do happen, they often include repeated ear, sinus, or lung infections, and sometimes long-lasting diarrhea or other stomach problems. The condition is also linked with allergies, asthma, autoimmune diseases, and celiac disease, a gut problem triggered by eating gluten.
Causes and who gets it
Doctors do not fully understand what causes selective IgA deficiency. It is one of the most common immune deficiencies, affecting about 1 in 300 to 1 in 500 people. It can run in families and is slightly more common in men.
How doctors diagnose it
Doctors diagnose selective IgA deficiency with a blood test that measures antibody levels, called immunoglobulins. The diagnosis is made when IgA is very low or absent while IgG and IgM are normal.
Treatment
Most people do not need treatment for the deficiency itself. Infections are treated with antibiotics when needed. Allergies, asthma, celiac disease, and autoimmune conditions are managed with standard treatments. There is no way to replace IgA, but most people live normal, healthy lives.
When to see a doctor
See a doctor if you have repeated ear, sinus, or lung infections, or ongoing diarrhea that does not go away. Get medical care if an infection causes high fever, trouble breathing, or does not improve with treatment. Anyone diagnosed with selective IgA deficiency should have regular checkups to watch for related conditions.
How a direct primary care or concierge doctor fits in
A direct primary care doctor is paid with a flat monthly fee instead of using insurance for visits. For selective IgA deficiency, this kind of doctor can order blood tests, make the diagnosis, treat routine infections, and follow the patient over time with longer appointments. If infections become frequent or serious, they would refer the patient to an immunologist.
Common questions
Is selective IgA deficiency serious?
For most people, it is mild. Many people never have symptoms. Others have repeated infections that can be managed with a doctor's help.
Can it go away?
IgA levels sometimes return to normal on their own, especially in children. This does not happen for everyone. Doctors may retest blood levels over time.
Can I donate blood if I have it?
People with selective IgA deficiency are usually told not to donate blood or plasma. Rarely, donated blood products containing IgA can cause a serious allergic reaction in these patients.
Will my children have it?
The condition can run in families, but the pattern is not simple. Many children of a parent with the condition do not have it. Genetic counseling can help families who want more information.
Sources
- NIH Genetic and Rare Diseases Information Center - Immunoglobulin A deficiency 2
- MedlinePlus - Congenital fibrinogen deficiency
- American Academy of Allergy, Asthma and Immunology - Selective IgA Deficiency Symptoms, Diagnosis & Treatment
Medical Disclaimer
This content is for general educational and informational purposes only and is not medical advice. It is not a substitute for professional medical advice, diagnosis, or treatment, and reading it does not create a doctor-patient relationship. Always seek the advice of your physician or another qualified health provider with any questions about a medical condition, and never disregard or delay seeking professional advice because of something you read here. If you think you may have a medical emergency, call 911 (or your local emergency number) immediately.
