Selective IgA Deficiency
Primary Selective Humoral Immunodeficiency
Primary risk age: Preschoolers through Adolescents (Often diagnosed during evaluations for recurrent infections or celiac disease)
- Urgency
- Mild
- Typical age
- Preschoolers through Adolescents (Often diagnosed during evaluations for recurrent infections or celiac disease)
- Body system
- Immunological & Allergic
Typical course: This is a lifelong genetic immune configuration; infections are managed as they occur.
Reviewed against AAP · CDC · WHO · NHS guidance Last reviewed 2026-06-13
1. Summary & Pathophysiology
Primary Selective Humoral Immunodeficiency
Pathophysiology (Development Path)
The selective absence or reduction of immunoglobulin A (IgA) in the blood and mucosal secretions (saliva, tears, gut). Because IgA is the primary defense at mucosal barriers, its absence increases susceptibility to respiratory and gastrointestinal pathogens.
Primary Causes & Etiology
Unknown etiology; genetic factors lead to a failure of B-lymphocytes to mature into IgA-producing plasma cells.
2. Symptom Continuum
- Early Onset Signs
Often completely asymptomatic. The child may exhibit slightly more frequent viral upper respiratory tract infections.
- Progressive Phase
Recurrent otitis media, sinusitis, bronchitis, or chronic gastroenteritis. Increased incidence of atopic diseases (asthma, eczema).
- Severe Indicators
Development of autoimmune disorders (such as Celiac disease, Juvenile Idiopathic Arthritis, or ITP). Anaphylactic reactions can occur when receiving blood products containing trace amounts of IgA (antibodies are generated against foreign IgA).
3. Clinical Verification
Serum IgA levels <7 mg/dL with normal IgG and IgM levels in a child older than 4 years (to rule out transient delay).
4. Care & Elements Plan
Primary Care Treatment Plan
Manage active infections promptly with antibiotics. Monitor for associated autoimmune diseases. Standard immunoglobulin replacement (IVIG) is not indicated and is contraindicated due to anaphylaxis risks.
Home Support Elements
Wear a medical alert bracelet indicating IgA deficiency to prevent accidental administration of standard blood products. Practice good hand hygiene and seek care early for respiratory infections.
Generic Active Ingredients (No Brands)
- None. Antibiotic therapy is used only to treat active bacterial infections.
Lists active elements only. Never administer self-designed therapies.
5. Doctor Critical Lines
Critical Thresholds: When to See a Doctor
Consult a pediatrician if your child has recurrent respiratory infections, persistent diarrhea, or develops joint pain or chronic skin rashes.
6. Vaccine & Prevention
Routine Prophylaxis (Prevention)
No preventative measures exist, as this is a primary immunodeficiency.
Immunization Context
Children can receive all routine immunizations, including live vaccines, as T-cell function remains intact.
7. Timelines & Outlook
Active Timeline
This is a lifelong genetic immune configuration; infections are managed as they occur.
Expected Prognosis
Excellent. Most children have a normal lifespan and remain asymptomatic, though ongoing monitoring for autoimmune diseases is required.
Potential Untreated Complications
Autoimmune diseases (Celiac, JIA), chronic lung disease from recurrent infections, and anaphylaxis to blood transfusions.
