Medical Conditions

Selective IgA Deficiency in Children

Medically reviewed by Dr. Michael Okonkwo, MD, FAAP · Board-Certified Neonatologist

Content reviewed against published AAP, NIH, IDF guidelines

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If your baby has been diagnosed with or you suspect selective iga deficiency in children, here is what the evidence says.

The short answer

Selective IgA deficiency is the most common primary immunodeficiency, affecting about 1 in 300-700 people. IgA is the main antibody found in mucous membranes (respiratory tract, gut, saliva, tears) and is the first line of defense against infections at these surfaces. Many people with IgA deficiency are completely asymptomatic and never diagnosed. Others experience more frequent respiratory or gastrointestinal infections, increased allergies, or associated autoimmune conditions. There is no replacement therapy for IgA specifically, but most children with IgA deficiency do well with supportive care.

Key takeaways

  • Selective IgA deficiency is the most common primary immunodeficiency, affecting about 1 in 300-700 people. IgA is the main antibody found in mucous membranes (respiratory tract, gut, saliva, tears) and is the first line of defense against infections at these surfaces. Many people with IgA deficiency are completely asymptomatic and never diagnosed. Others experience more frequent respiratory or gastrointestinal infections, increased allergies, or associated autoimmune conditions. There is no replacement therapy for IgA specifically, but most children with IgA deficiency do well with supportive care.
  • Usually normal when: Your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency
  • Call your doctor if: Your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products
  • Varies by age — see the age-by-age breakdown below
“Fever itself is not an illness — rather, it is a sign or symptom that the body is fighting an infection. Fever stimulates certain defenses, such as the white blood cells, which attack and destroy invading bacteria.”
— Fever and Your Child, American Academy of Pediatrics (AAP)

This is one of the most common questions parents ask. Searching for answers means you care.

What Parents Should Know

According to AAP, NIH, IDF guidelines, selective IgA deficiency is the most common primary immunodeficiency, affecting about 1 in 300-700 people. IgA is the main antibody found in mucous membranes (respiratory tract, gut, saliva, tears) and is the first line of defense against infections at these surfaces. Many people with IgA deficiency are completely asymptomatic and never diagnosed. Others experience more frequent respiratory or gastrointestinal infections, increased allergies, or associated autoimmune conditions. There is no replacement therapy for IgA specifically, but most children with IgA deficiency do well with supportive care. At 0-6 months, igA deficiency is rarely diagnosed this early because IgA levels are normally very low in infants — IgA does not reach adult levels until around age 5-7. Maternal antibodies and breastmilk (which contains IgA) provide protection. If your baby has other immune testing done for another reason and IgA is low, this is expected at this age and does not necessarily indicate IgA deficiency. It is generally considered normal when your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency. However, you should contact your pediatrician promptly if your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products.

Sources: [1], [2], [3]

Normal vs. Concerning

Usually Normal
Worth Discussing
Your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency
Your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products
Your young child has a low IgA level that is being monitored — IgA levels do not reach adult values until age 5-7
Your child with IgA deficiency develops signs of a more severe immunodeficiency (recurrent pneumonia, deep infections, failure to thrive), which may suggest progression to common variable immunodeficiency (CVID)
Your child with IgA deficiency gets occasional respiratory or ear infections that resolve with standard treatment
Your child with IgA deficiency has more frequent infections than expected (4+ ear infections per year, recurrent sinusitis, or recurrent pneumonia)
Your child with IgA deficiency has mild seasonal allergies that are well controlled
Your child with IgA deficiency is developing symptoms of autoimmune disease (chronic diarrhea, joint pain, persistent rash)

By Age

What to expect by age

0-6 months

IgA deficiency is rarely diagnosed this early because IgA levels are normally very low in infants — IgA does not reach adult levels until around age 5-7. Maternal antibodies and breastmilk (which contains IgA) provide protection. If your baby has other immune testing done for another reason and IgA is low, this is expected at this age and does not necessarily indicate IgA deficiency.

6-12 months

IgA levels remain very low in normal infants, so a definitive diagnosis of selective IgA deficiency cannot be made at this age. If your baby is having frequent infections, your doctor may check immunoglobulin levels to look for broader immune problems. A low IgA alone at this age requires follow-up testing at an older age rather than immediate diagnosis.

1-3 years

IgA levels are still rising in toddlers and do not reach adult levels until age 5-7. A tentative diagnosis of IgA deficiency can be considered if IgA is undetectable (below 7 mg/dL) with normal IgG and IgM levels in a child over 4 years old. In toddlers, a very low IgA level should be monitored over time. Some children have transient low IgA that normalizes. Toddlers with IgA deficiency may experience more ear infections, sinus infections, or gastrointestinal infections than their peers.

3+ years

The diagnosis of selective IgA deficiency is confirmed when IgA is below 7 mg/dL in a child over age 4 with normal IgG and IgM and no other cause of immunodeficiency. About two-thirds of affected children are asymptomatic. Those with symptoms may have increased respiratory infections, gastrointestinal infections, a higher rate of allergies (asthma, eczema, food allergies), and increased risk of autoimmune conditions like celiac disease or juvenile arthritis. An important medical alert: people with complete IgA deficiency can develop anti-IgA antibodies and may have severe allergic reactions if given IgA-containing blood products.

What to Tell Your Pediatrician

  • Describe when you first noticed selective iga deficiency in children and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if your child with IgA deficiency has more frequent infections than expected (4+ ear infections per year, recurrent sinusitis, or recurrent pneumonia).
  • Mention if your child with IgA deficiency is developing symptoms of autoimmune disease (chronic diarrhea, joint pain, persistent rash).
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

What Should You Do?

When to take action

Probably normal when...
  • Your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency
  • Your young child has a low IgA level that is being monitored — IgA levels do not reach adult values until age 5-7
  • Your child with IgA deficiency gets occasional respiratory or ear infections that resolve with standard treatment
  • Your child with IgA deficiency has mild seasonal allergies that are well controlled
Mention at your next visit when...
  • Your child with IgA deficiency has more frequent infections than expected (4+ ear infections per year, recurrent sinusitis, or recurrent pneumonia)
  • Your child with IgA deficiency is developing symptoms of autoimmune disease (chronic diarrhea, joint pain, persistent rash)
  • You want to discuss whether your child with IgA deficiency needs a medical alert bracelet or notification about blood products
Act now when...
  • Your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products
  • Your child with IgA deficiency develops signs of a more severe immunodeficiency (recurrent pneumonia, deep infections, failure to thrive), which may suggest progression to common variable immunodeficiency (CVID)

What You Can Do at Home

  • Keep track of when you notice selective iga deficiency in children — noting the time of day, duration, and any triggers can help your pediatrician.
  • Remember that your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency — this is generally within the range of normal.
  • At 0-6 months, focus on observation rather than intervention unless your pediatrician advises otherwise.
  • Follow any care instructions from your pediatrician. Keep a written log of symptoms to bring to appointments.
  • While monitoring at home, seek immediate care if your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products.

Signs of Primary Immunodeficiency in Babies

Primary immunodeficiency disorders are conditions where the immune system does not function properly from birth. Warning signs include 4 or more new ear infections in a year, 2 or more serious sinus infections in a year, 2 or more months on antibiotics with little effect, 2 or more pneumonias in a year, failure to thrive, recurrent deep skin or organ abscesses, and a family history of primary immunodeficiency. These conditions are rare but treatable when identified early.

Warning Signs of Primary Immunodeficiency in Children

Primary immunodeficiency diseases (PIDs) are a group of over 450 genetic conditions where the immune system does not function properly. The Jeffrey Modell Foundation has identified 10 warning signs in children: 4+ new ear infections in a year, 2+ serious sinus infections in a year, 2+ months on antibiotics with little effect, 2+ pneumonias in a year, failure to gain weight or grow normally, recurrent deep skin or organ abscesses, persistent thrush in mouth or fungal infection on skin, need for IV antibiotics to clear infections, 2+ deep-seated infections (sepsis, meningitis), and a family history of PID. If your child meets 2 or more of these criteria, discuss immunologic testing with your pediatrician.

Transient Hypogammaglobulinemia of Infancy

Transient hypogammaglobulinemia of infancy (THI) is a condition where a baby's immunoglobulin (antibody) levels — particularly IgG — drop lower than expected during the normal transition between losing maternal antibodies and producing their own. This physiologic dip normally occurs around 3-6 months of age, but in THI it is more pronounced or prolonged. Most children with THI are either asymptomatic or have mildly increased infections and outgrow the condition by age 2-4 years as their own antibody production matures. THI is generally benign and is not a true primary immunodeficiency.

Recurring Ear Infections in Babies

Recurrent ear infections are common in babies and toddlers because their Eustachian tubes are shorter and more horizontal than adults', making them prone to fluid buildup and infection. Three or more ear infections in six months, or four in twelve months, is considered recurrent and may warrant referral to an ENT specialist. Ear tubes (tympanostomy tubes) are a safe, common procedure that can significantly reduce infection frequency.

Milestone

Month-by-Month Development

Detailed monthly development guides from birth through 24 months.

Guide

When to Call the Doctor

General guide on when to call the pediatrician, visit urgent care, or go to the ER.

Frequently asked questions

Is selective iga deficiency in children normal?
Selective IgA deficiency is the most common primary immunodeficiency, affecting about 1 in 300-700 people. IgA is the main antibody found in mucous membranes (respiratory tract, gut, saliva, tears) and is the first line of defense against infections at these surfaces. Many people with IgA deficiency are completely asymptomatic and never diagnosed. Others experience more frequent respiratory or gastrointestinal infections, increased allergies, or associated autoimmune conditions. There is no replacement therapy for IgA specifically, but most children with IgA deficiency do well with supportive care.
When should I call the doctor about selective iga deficiency in children?
Your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products Your child with IgA deficiency develops signs of a more severe immunodeficiency (recurrent pneumonia, deep infections, failure to thrive), which may suggest progression to common variable immunodeficiency (CVID)
When is selective iga deficiency in children normal?
Your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency Your young child has a low IgA level that is being monitored — IgA levels do not reach adult values until age 5-7 Your child with IgA deficiency gets occasional respiratory or ear infections that resolve with standard treatment
What causes selective iga deficiency in children?
Selective IgA deficiency is the most common primary immunodeficiency, affecting about 1 in 300-700 people. IgA is the main antibody found in mucous membranes (respiratory tract, gut, saliva, tears) and is the first line of defense against infections at these surfaces. Many people with IgA deficiency are completely asymptomatic and never diagnosed. Others experience more frequent respiratory or gastrointestinal infections, increased allergies, or associated autoimmune conditions. There is no replacement therapy for IgA specifically, but most children with IgA deficiency do well with supportive care. Common explanations include: Your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency. Your young child has a low IgA level that is being monitored — IgA levels do not reach adult values until age 5-7.
What should I mention to my pediatrician about selective iga deficiency in children?
You should mention selective iga deficiency in children at your next visit if: Your child with IgA deficiency has more frequent infections than expected (4+ ear infections per year, recurrent sinusitis, or recurrent pneumonia). Your child with IgA deficiency is developing symptoms of autoimmune disease (chronic diarrhea, joint pain, persistent rash). You want to discuss whether your child with IgA deficiency needs a medical alert bracelet or notification about blood products.
Is selective iga deficiency in children normal at 0-6 months?
IgA deficiency is rarely diagnosed this early because IgA levels are normally very low in infants — IgA does not reach adult levels until around age 5-7. Maternal antibodies and breastmilk (which contains IgA) provide protection. If your baby has other immune testing done for another reason and IgA is low, this is expected at this age and does not necessarily indicate IgA deficiency.
Is selective iga deficiency in children normal at 6-12 months?
IgA levels remain very low in normal infants, so a definitive diagnosis of selective IgA deficiency cannot be made at this age. If your baby is having frequent infections, your doctor may check immunoglobulin levels to look for broader immune problems. A low IgA alone at this age requires follow-up testing at an older age rather than immediate diagnosis.
Should I go to the ER for selective iga deficiency in children?
Seek emergency care if your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products, or if your child with IgA deficiency develops signs of a more severe immunodeficiency (recurrent pneumonia, deep infections, failure to thrive), which may suggest progression to common variable immunodeficiency (CVID). When in doubt, call your pediatrician's after-hours line for guidance.
Does selective iga deficiency in children go away on its own?
In many cases, selective iga deficiency in children resolves on its own, especially when your child has IgA deficiency but rarely gets sick and is growing and developing normally — this is the case for the majority of people with IgA deficiency. By 3+ years, the diagnosis of selective IgA deficiency is confirmed when IgA is below 7 mg/dL in a child over age 4 with normal IgG and IgM and no other cause of immunodeficiency. About two-thirds of affected children are asymptomatic. Those with symptoms may have increased respiratory infections, gastrointestinal infections, a higher rate of allergies (asthma, eczema, food allergies), and increased risk of autoimmune conditions like celiac disease or juvenile arthritis. An important medical alert: people with complete IgA deficiency can develop anti-IgA antibodies and may have severe allergic reactions if given IgA-containing blood products.
AAPNIHIDF

References

  1. [1]American Academy of Pediatrics. Primary Immunodeficiency Diseases. Pediatrics in Review, 2019. AAP
  2. [2]National Institute of Allergy and Infectious Diseases. Selective IgA Deficiency. NIAID, 2023. NIH
  3. [3]Immune Deficiency Foundation. IgA Deficiency. IDF Patient & Family Handbook, 2024. IDF

Doctor Visit Checklist

Bring this checklist to your next pediatrician visit to discuss Selective IgA Deficiency in Children.

Things to mention

  • Describe when you first noticed selective iga deficiency in children and how it has changed over time.
  • Note your baby's current age and which age-specific patterns you are seeing.
  • Mention if your child with IgA deficiency has more frequent infections than expected (4+ ear infections per year, recurrent sinusitis, or recurrent pneumonia).
  • Mention if your child with IgA deficiency is developing symptoms of autoimmune disease (chronic diarrhea, joint pain, persistent rash).
  • Let your doctor know if you have noticed any related concerns, such as changes in feeding, sleep, or movement patterns.
  • Bring a list of any questions or observations you want to discuss at the appointment.

Observations to share

  • Your child with IgA deficiency has more frequent infections than expected (4+ ear infections per year, recurrent sinusitis, or recurrent pneumonia)
  • Your child with IgA deficiency is developing symptoms of autoimmune disease (chronic diarrhea, joint pain, persistent rash)
  • You want to discuss whether your child with IgA deficiency needs a medical alert bracelet or notification about blood products

Urgent signs to report immediately

  • Your child with known IgA deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to IgA in the blood products
  • Your child with IgA deficiency develops signs of a more severe immunodeficiency (recurrent pneumonia, deep infections, failure to thrive), which may suggest progression to common variable immunodeficiency (CVID)

My notes

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Bottom line

Most cases of selective iga deficiency in children are normal. Talk to your pediatrician if your child with known iga deficiency is receiving a blood transfusion or blood products and develops hives, difficulty breathing, or anaphylaxis — this could be a reaction to iga in the blood products.

Trust your instincts. If something feels wrong, reach out to your pediatrician. Worrying about your baby means you care — that is a good thing.

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Signs of Primary Immunodeficiency in Babies

Primary immunodeficiency disorders are conditions where the immune system does not function properly from birth. Warning signs include 4 or more new ear infections in a year, 2 or more serious sinus infections in a year, 2 or more months on antibiotics with little effect, 2 or more pneumonias in a year, failure to thrive, recurrent deep skin or organ abscesses, and a family history of primary immunodeficiency. These conditions are rare but treatable when identified early.

Warning Signs of Primary Immunodeficiency in Children

Primary immunodeficiency diseases (PIDs) are a group of over 450 genetic conditions where the immune system does not function properly. The Jeffrey Modell Foundation has identified 10 warning signs in children: 4+ new ear infections in a year, 2+ serious sinus infections in a year, 2+ months on antibiotics with little effect, 2+ pneumonias in a year, failure to gain weight or grow normally, recurrent deep skin or organ abscesses, persistent thrush in mouth or fungal infection on skin, need for IV antibiotics to clear infections, 2+ deep-seated infections (sepsis, meningitis), and a family history of PID. If your child meets 2 or more of these criteria, discuss immunologic testing with your pediatrician.

Transient Hypogammaglobulinemia of Infancy

Transient hypogammaglobulinemia of infancy (THI) is a condition where a baby's immunoglobulin (antibody) levels — particularly IgG — drop lower than expected during the normal transition between losing maternal antibodies and producing their own. This physiologic dip normally occurs around 3-6 months of age, but in THI it is more pronounced or prolonged. Most children with THI are either asymptomatic or have mildly increased infections and outgrow the condition by age 2-4 years as their own antibody production matures. THI is generally benign and is not a true primary immunodeficiency.

Recurring Ear Infections in Babies

Recurrent ear infections are common in babies and toddlers because their Eustachian tubes are shorter and more horizontal than adults', making them prone to fluid buildup and infection. Three or more ear infections in six months, or four in twelve months, is considered recurrent and may warrant referral to an ENT specialist. Ear tubes (tympanostomy tubes) are a safe, common procedure that can significantly reduce infection frequency.

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