Recurrent Sinus Infections: Signs of Immune Deficiency and When to Get Tested

Recurrent Sinus Infections: Signs of Immune Deficiency and When to Get Tested

If you’re stuck in a cycle of congestion, pressure, post-nasal drip, and multiple rounds of antibiotics—only for symptoms to return—it’s understandable to wonder what’s being missed. Many people describe it as: “I get better for a week or two… then it’s right back to square one.” Importantly, antibiotics aren’t always the right tool; many sinus flares are viral or inflammatory, and responsible antibiotic use (stewardship) helps prevent side effects and resistance.

Many patients with frequent sinus symptoms are dealing with anatomy, allergies, or chronic inflammation. But research shows a meaningful subset of people with recurrent or difficult-to-treat chronic rhinosinusitis (CRS) also have underlying immune problems—especially antibody deficiency. In one review, immune deficiencies were identified in roughly 13%–23% of patients with recurrent or refractory CRS (and higher in some studies). [1]

This article is educational (not personal medical advice), but it can help you understand when recurrent sinus infections may warrant an immune workup, what testing typically involves, and which next steps to discuss with an ENT or allergist/immunologist.

What counts as “recurrent” or “chronic” sinus infections?

Recurrent acute sinusitis vs. chronic rhinosinusitis (CRS)

The label matters because it helps guide evaluation and treatment—and because “sinus infection” is often used as a catch-all for several different problems.

• Recurrent acute sinusitis generally means multiple distinct infection-like episodes per year, with clear improvement between episodes.

• Chronic rhinosinusitis (CRS) is typically defined by symptoms lasting 12 weeks or longer, such as nasal congestion or obstruction, nasal drainage or post-nasal drip, facial pressure or pain, and reduced sense of smell.

It’s also important to know that many “sinus infections” are viral or inflammatory, not bacterial—so antibiotics aren’t always the right tool. A common story is a “sinus infection” that improves briefly on antibiotics mainly because swelling calms down, then flares again when inflammation returns.

If you want a deeper breakdown, see acute vs. chronic sinusitis: what’s the difference? https://sleepandsinuscenters.com/blog/acute-vs-chronic-sinusitis-key-differences-and-treatment-options and viral vs. bacterial sinus infections: key differences https://sleepandsinuscenters.com/blog/viral-vs-bacterial-sinus-infections-key-differences.

Bottom line: Accurate labeling helps target care—and can prevent unnecessary antibiotics.

Why this distinction matters for immune testing

Immune evaluation is usually considered when infections are frequent, unusually severe, prolonged, complicated, or treatment-resistant—especially in people with recurrent or refractory CRS. [1] In other words, the pattern over time (how often, how long, how hard to treat) is often more informative than any single episode.

A practical way to think about it: one tough month doesn’t necessarily signal an immune problem—but a repeated pattern over years sometimes does.

Bottom line: Patterns that repeat over time are the strongest signal that immune testing may help.

The immune system connection: why antibody problems show up as sinus issues

What antibodies do (in plain language)

Antibodies are proteins your immune system uses to recognize germs and help clear them. They’re especially important for defending against bacteria that commonly infect the sinuses and lungs.

A helpful analogy: antibodies work a bit like “wanted posters” for your immune system—marking what to target so your body can respond faster and more effectively the next time.

When antibody function is reduced, some people experience a repeating pattern of: sinus infections that keep returning; infections that linger longer than expected; infections that spread beyond the sinuses (for example, into the chest).

Bottom line: When antibodies underperform, sinus and chest infections can become frequent or prolonged.

Why the sinuses are a common “trouble spot”

The sinuses are small, air-filled spaces with narrow drainage pathways. When inflammation swells the lining (from allergies, viruses, irritants, or polyps), mucus can get trapped—creating an environment where bacteria can take hold. If antibody defenses are also weaker, it can become much harder to fully clear infections.

Bottom line: Narrow drainage plus inflammation makes sinuses vulnerable—especially if antibody defenses are reduced.

Common immune deficiencies linked to recurrent/difficult CRS

Several immune conditions are reported more often in people with CRS than in the general population, including: [1][2] Selective IgA deficiency; IgG deficiency (including some IgG subclass deficiencies); Specific Antibody Deficiency (SAD), where total IgG may look normal but the body doesn’t make effective antibodies after certain vaccines.

Bottom line: A few common, testable antibody issues can drive recurrent sinus problems.

Symptoms and warning signs that suggest an immune deficiency (not just “bad sinuses”)

If several of these sound like you, consider asking about immune testing.

Infection-pattern red flags

Patterns that often prompt discussion of immune evaluation include: [1]

• Four or more infections requiring antibiotics in a year (or similarly frequent bacterial infections)

• Infections that require unusually long or repeated antibiotic courses

• Symptoms that do not respond as expected to typical treatment prescribed by your healthcare provider

• Back-to-back infections or symptoms that never fully clear

• Unusually severe infections or infections with complications

Concrete example: If you’ve had “sinus infections” in January, March, June, and September—each time needing antibiotics and missing work or school—and you never quite return to your baseline breathing, that’s the kind of pattern clinicians take seriously.

Beyond the sinuses: clues elsewhere in the body

Immune concerns become more likely when sinus problems are part of a bigger pattern, such as frequent episodes of bronchitis or pneumonia; recurrent ear infections; persistent cough or frequent need for oral steroids; a family history of primary immunodeficiency.

A clinician might summarize it like this: “If it’s only the nose, we often start with inflammation and anatomy. If it’s the nose and the chest, we think harder about immune function.”

When to seek urgent care (rule-out emergencies)

Sinus symptoms rarely become emergencies, but certain signs should be treated as urgent—such as high fever with severe headache, swelling around the eyes, vision changes, stiff neck, confusion, rapidly worsening facial swelling, or severe shortness of breath. These require immediate medical attention.

Bottom line: A recurring, hard-to-treat pattern—especially if the chest is involved—warrants an immune conversation.

Causes of recurrent sinus infections (immune-related and non-immune)

Non-immune causes that commonly mimic “recurrent infection”

A lot of infection-like sinus symptoms come from inflammation or airflow/drainage problems, including allergic rhinitis; non-allergic rhinitis; nasal polyps or ongoing chronic inflammation; anatomical blockage (for example, a deviated septum or narrow drainage pathways); environmental irritants (smoke, pollution, workplace exposures).

In these cases, antibiotics may temporarily change symptoms without solving the root issue. For example, if a narrow drainage pathway keeps closing due to swelling, mucus may keep pooling—leading to repeated flares.

If structural blockage is part of the picture, a focused evaluation can help clarify options. Related reading: deviated septum (nasal blockage) evaluation https://sleepandsinuscenters.com/deviated-septum-relief.

Immune-related causes (where testing changes the plan)

In some patients, repeated bacterial infections are driven by antibody deficiency (IgA, IgG, or SAD). Identifying this matters because it can change prevention strategies, vaccine planning, and long-term management. [1]

Bottom line: Anatomy and inflammation are common drivers—but antibody issues can be the missing piece.

When should you get tested for immune deficiency?

Reasonable testing triggers (clear checklist)

It may be reasonable to discuss an immune workup if you have: [1] recurrent or difficult-to-treat CRS despite appropriate care (for example, saline irrigation, topical nasal steroid sprays when recommended, and allergy management); four or more antibiotic courses per year for suspected bacterial sinus infections; infections requiring unusually long courses of antibiotics or IV antibiotics; recurrent sinusitis plus recurrent chest infections.

This is one of the key moments when the question “Are these recurrent sinus infections actually a sign of immune deficiency?” becomes worth exploring.

Which specialist should you see?

Many people start with an ENT to confirm CRS, assess nasal anatomy, and look for polyps or blockage. Others benefit from evaluation with an allergist/immunologist to assess immune function and allergic triggers. Coordination often helps, especially when symptoms are persistent. [3]

If you’re unsure where to begin, this guide can help: when to see an ENT https://sleepandsinuscenters.com/blog/when-should-i-see-an-ent. You can also explore chronic sinusitis (CRS) evaluation and care https://sleepandsinuscenters.com/chronic-sinusitis and allergy testing to rule in/out triggers https://sleepandsinuscenters.com/allergy-testing through Sleep and Sinus Centers of Georgia.

Bottom line: If frequent, hard-to-treat sinus issues keep returning, talk to ENT and immunology specialists.

What tests are typically ordered? (patient-friendly explanation)

Baseline bloodwork

Common starting tests include: Quantitative immunoglobulins (IgG, IgA, IgM); IgG subclasses (in select cases); CBC with differential (a general look at white blood cells and overall immune cell patterns).

If results are abnormal, your clinician may discuss whether the findings fit a primary immune issue or a secondary cause (like medication effects or protein loss).

“Do your antibodies work?” testing (vaccine response)

A key step in evaluating antibody function is vaccine response testing. This may involve measuring antibody levels to prior vaccines (often tetanus and/or pneumococcal), and/or giving a vaccine (commonly pneumococcal) and re-checking antibody levels a few weeks later to see whether the immune system makes an appropriate response. [1]

This testing is performed under medical supervision to ensure it’s appropriate and timed correctly. It is especially relevant for identifying Specific Antibody Deficiency, where total IgG can be normal but vaccine responses are inadequate. [2]

A simple way to think about it: the lab isn’t only asking “Do you have antibodies?”—it’s also asking “Can you make the right antibodies when prompted?”

Additional testing (case-by-case)

Depending on the situation, clinicians may also evaluate secondary causes of low immunoglobulins (certain medications, protein loss, other medical conditions), and use sinus imaging and/or nasal endoscopy to clarify whether symptoms are driven primarily by inflammation, anatomy, infection—or a mix.

Bottom line: Immune testing looks at both quantity and function—ordered and interpreted by specialists.

Treatment options if immune deficiency is found (and how sinus care changes)

Optimize prevention first

Specialists may recommend updated or targeted vaccination strategies when appropriate. [1] Prevention plans often work best when they’re personalized to your infection history and risk factors.

Antibiotic strategy (more personalized)

When infections recur, some patients benefit from culture-guided antibiotics (treating based on what bacteria are actually present) and specialist-directed prevention plans, which may include antibiotics in select cases (not right for everyone).

Because antibiotics have risks—including side effects, C. difficile infection, and antibiotic resistance—preventive or long-term antibiotics are used only when benefits clearly outweigh risks and with close monitoring.

Immunoglobulin replacement therapy (IVIG/SCIG): who may benefit

For certain antibody deficiencies, immunoglobulin replacement therapy (IVIG or SCIG) may reduce infection frequency and improve quality of life in appropriately selected patients. [1][3] This treatment is typically managed by an immunology specialist and monitored over time.

ENT-directed CRS management still matters

Even when immune deficiency is present, day-to-day CRS care can remain essential: saline irrigation; topical nasal steroid sprays (when recommended); treatment for polyps or inflammation; procedures or surgery when blockage is a major driver (immune treatment doesn’t correct a structural obstruction).

Many patients ultimately do best with a “both/and” plan: immune support plus sinus-focused care.

Bottom line: Pair immune-specific care with targeted ENT management for the best long-term results.

Lifestyle tips to reduce recurrence (supportive care that helps most patients)

Daily habits that protect the sinuses

• Use regular saline rinses (with sterile or distilled water; if using tap water, boil for at least 1 minute and cool before use; keep devices clean).

• Use prescribed nasal sprays consistently as directed.

• Support hydration and manage indoor humidity (especially in dry seasons).

For technique and safety details: how to use a neti pot safely https://sleepandsinuscenters.com/blog/neti-pot-safety-tips-essential-steps-for-safe-nasal-irrigation.

Reduce triggers that keep inflammation “switched on”

• Avoid smoke exposure when possible; limit strong fragrances and irritants; improve indoor air quality; evaluate allergies and follow a structured plan if present (learn more: allergy testing https://sleepandsinuscenters.com/allergy-testing).

Track patterns to improve diagnosis

A simple log can help clarify whether you’re dealing with inflammation, infections, or both: start and end dates of symptoms; fever or no fever; color and character of drainage; antibiotic start/stop dates and response; missed work or school days; chest symptoms (cough, wheeze, episodes of bronchitis).

This kind of record is often helpful when discussing recurrent sinus infections and possible immune deficiency.

Bottom line: Daily consistency, trigger control, and a simple symptoms log can meaningfully reduce setbacks.

FAQs

How many sinus infections per year is too many?

A commonly used screening threshold is four or more infections requiring antibiotics in a year, especially if episodes are severe, prolonged, or don’t respond as expected. The overall pattern (frequency, duration, complications) is usually more important than a single number. [1]

Can I have an immune deficiency if my labs are “normal”?

Yes. Specific Antibody Deficiency can occur when total immunoglobulin levels (like IgG) are normal but the body doesn’t produce adequate protective antibodies after vaccination. That’s why vaccine response testing can be an important part of evaluation. [2]

Will immune testing replace the need for ENT care or sinus surgery?

Usually not. Immune evaluation can explain why infections keep returning and help reduce infectious flares, but anatomy and chronic inflammation may still need ENT-directed treatment.

What’s the difference between allergies and immune deficiency?

Allergies are an overreaction of the immune system to triggers like pollen, dust mites, or pets. Immune deficiency is an underperformance against infections. Some people have both, which can amplify symptoms.

Is immunoglobulin therapy safe?

Immunoglobulin therapy is well-established and used for a range of antibody deficiencies, but benefits, risks, and monitoring vary by individual. It requires specialist oversight and follow-up. [3]

When to book an appointment

If you recognize the warning signs—especially frequent antibiotics, symptoms lasting 12+ weeks, or recurrent sinus infections plus chest infections—consider scheduling an evaluation. Bringing a timeline of infections, medications, prior CT scans, and any allergy testing results can make the visit more productive.

To take the next step, you can book an appointment or learn more at Sleep and Sinus Centers of Georgia: https://www.sleepandsinuscenters.com/ You can also review chronic sinusitis (CRS) evaluation and care https://sleepandsinuscenters.com/chronic-sinusitis and allergy testing to rule in/out triggers https://sleepandsinuscenters.com/allergy-testing before your visit.

Bottom line: If the same sinus story keeps repeating, coordinated ENT and immunology care can change the trajectory.

Sources

[1]: Immune deficiency prevalence in refractory/recurrent CRS and guidance on immune evaluation/testing: https://pmc.ncbi.nlm.nih.gov/articles/PMC5429028/

[2]: Antibody deficiency, vaccine response, and CRS discussion (JACI): https://www.jacionline.org/article/S0091-6749(15)01020-9/fulltext

[3]: Patient-focused guidance on managing sinus issues with primary immunodeficiency: https://primaryimmune.org/resources/news-articles/managing-sinus-issues

Disclaimer: This article is for educational purposes only and is not medical advice. Please consult a qualified healthcare provider for diagnosis and treatment.