The Sinus Blog

If you never had allergies until now and suddenly spend every spring sneezing, you’re not imagining it. Yes, you can develop allergies as an adult. The American Academy of Allergy, Asthma & Immunology notes that about 20% of people with hay fever first develop symptoms after age 20. A study published this fall in the journal Immunity also offers a new explanation for why repeated exposures can turn a harmless pollen into a problem.

Dr. Brad Bichey, a board-certified otolaryngologist who sees allergy-driven sinus problems daily at Indiana Sinus Centers in Carmel and Fort Wayne, walks through what the research shows and what to do when allergies show up later in life.

Adult onset allergies are common

Allergies are often thought of as a childhood problem, but the numbers say otherwise. In the CDC’s 2024 National Health Interview Survey data, 25.2% of U.S. adults had a diagnosed seasonal allergy. The rate peaked at 27.7% in adults ages 45 to 64, higher than in adults under 45. Women reported seasonal allergies more often than men, 29.5% versus 20.7%.

So the question isn’t really whether adults can develop an allergy. It’s why the immune system starts reacting to something it ignored for decades, and whether that reaction will last.

How allergies develop

An allergy is the immune system mistaking a harmless substance, such as pollen, dust mites or pet dander, for a threat. This overview of what allergies are explains the basic types, from seasonal allergic rhinitis to year-round reactions to indoor triggers. The reaction doesn’t happen on first contact. The body has to be exposed, become sensitized, and then react on later exposures.

New research: your nerves may remember allergens

In September 2026, researchers at Mass General Brigham reported in Immunity that sensory neurons, the nerve cells that sense itch, can keep a “memory” of earlier allergen exposures. In mice, an exposure too small to cause an allergic response on its own primed these nerves through a signaling pathway called mTORC1, so the next exposure produced a stronger reaction.

The priming also carried over to other allergens with similar enzyme activity, which may help explain why one allergy can make you more prone to others. The nerve memory faded over time. This was a mouse study, so it doesn’t change treatment yet, but it fits what Dr. Bichey hears from patients: symptoms that build over a few seasons rather than appearing overnight.

Why allergies start or get worse in adulthood

Most adult-onset allergies trace back to exposure. As Cleveland Clinic allergist Dr. Dylan Timberlake puts it in Cleveland Clinic’s guide to developing allergies later in life, every exposure to an allergen is another chance for the immune system to react. The same guide lists moving to a new area, hormonal changes such as pregnancy or menopause, and stress as common factors.

Moving to Indiana is a good example. Tree pollen starts in spring, which ISC covers in its guide to spring allergies in Indiana, grass follows into early summer, and ragweed season runs from mid-August until the first frost. Someone new to the state can go a season or two without symptoms and then start reacting once those exposures add up. The daily Indiana sinus forecast shows which pollens are high on a given day.

Family history matters too. Allergies run in families, though you won’t necessarily react to the same things your parents do. Can allergies get worse over time? Yes. Steady exposure and new sensitizations can make each season feel harder than the last.

Is it allergies or something else?

New nasal symptoms in adulthood aren’t always allergies. A cold usually clears in about a week, while allergies follow the pollen calendar and bring itchy eyes and sneezing. ISC’s guide to telling seasonal allergies from a sinus infection covers the differences.

A runny nose triggered by cold air, strong smells or spicy food, with no itching, may be non-allergic rhinitis, which this article on chronic runny nose and non-allergic rhinitis explains. And allergies that go untreated can keep the sinus lining swollen, which is why Dr. Bichey looks at the connection between allergies and sinusitis when facial pressure and thick drainage show up.

Can you grow out of allergies?

Children often outgrow some allergies. Adult-onset allergies are different. Cleveland Clinic notes that allergies appearing later in life tend to stick around, though they can be controlled with avoidance, medication or allergy shots.

Can allergies go away on their own in adults? Sometimes symptoms ease for a few years and come back, but planning on that isn’t a strategy. The Mass General Brigham team is studying whether the nerve memory can be reset, which could one day help prevent allergies, but that work is still in the lab.

What to do if you develop allergies as an adult

Start by identifying the trigger. Allergy skin testing places small amounts of common allergens on the skin and reads the results in about 15 to 20 minutes. You’ll need to stop antihistamines for several days beforehand.

For treatment, the American College of Allergy, Asthma and Immunology calls nasal steroid sprays the single most effective drug class for allergic rhinitis. Dr. Bichey usually starts there, and ISC’s guide to using Flonase correctly covers technique. Saline rinses help clear pollen from the nose. Immunotherapy, given as allergy shots or under-the-tongue tablets, is the only treatment that changes how your immune system responds. Shots typically run three to five years.

If symptoms last past two seasons of over-the-counter treatment, or you start getting sinus infections every spring, it’s time for a specialist. This guide to Midwest allergy symptoms and when to see a doctor lists the warning signs, and this comparison helps you decide whether to see an ENT or an allergist.

Frequently asked questions

Why did I never have allergies until now?

Allergies need repeated exposure to develop. A move, a new pet, or years of breathing the same pollen can eventually tip your immune system into reacting, and hormonal changes can lower that threshold.

Are allergies genetic?

Partly. Having a parent with allergies raises your risk, but you can develop allergies with no family history, and you may react to different allergens than your parents.

Getting new allergies under control

Allergies that start in adulthood are common, and they usually don’t fade on their own. Finding the trigger and treating the nose early keeps seasonal symptoms from turning into chronic sinus trouble. If new allergies are wearing you down, schedule a visit with Dr. Bichey at Indiana Sinus Centers in Carmel or Fort Wayne.

If your ear has felt clogged for days, there’s no wax in sight, and yawning does nothing, the likely cause is a eustachian tube that isn’t opening the way it should. Most eustachian tube dysfunction treatment starts in the nose, because that’s where the tube begins. According to Cleveland Clinic’s overview of eustachian tube dysfunction, most cases clear in one to two weeks. When they don’t, the plugged feeling can drag on for months.

Dr. Brad Bichey is a board-certified otolaryngologist who completed an NIH research fellowship in Indiana University’s DeVault Otologic Research Laboratory before his ENT residency. Below is the order he works through treatment at Indiana Sinus Centers in Carmel and Fort Wayne, from simple fixes at home to in-office balloon dilation.

What eustachian tube dysfunction feels like

Eustachian tube dysfunction (ETD) means the small tube linking your middle ear to the back of your nose can’t open, close or drain properly. Each tube normally opens for a split second when you swallow or yawn, letting in enough air to keep pressure equal on both sides of the eardrum.

Common eustachian tube dysfunction symptoms include:

• Ear fullness or a plugged feeling, often in one ear
• Muffled hearing
• Popping, clicking or crackling when you swallow
• Mild ear pain, ringing or a sense of imbalance

An ear that feels clogged but has no wax usually points to the tube, not the ear canal. A less common condition, a patulous eustachian tube that stays open, does the opposite: you hear your own voice and breathing too loudly. The two need different treatment, so the diagnosis matters. An ear that stays plugged alongside sinus symptoms is one of the signs it’s time to stop self-treating.

Why the problem usually starts in your nose

The eustachian tube opens into the back of the nasal cavity, so anything that swells the nasal lining can pinch it shut. Colds, allergies and sinus inflammation are the usual triggers. The 2019 AAO-HNS consensus statement on balloon dilation names allergic rhinitis, rhinosinusitis and reflux as conditions to treat before any procedure.

Indiana gives your nose plenty to react to. Tree pollen arrives in spring, grass follows into summer, and ragweed keeps fall congestion going until the first hard frost. Cold and flu season fills in the rest of the year. If you check the daily Indiana sinus forecast, you may notice your ears plug up on the same days your nose does.

Sinus disease is a frequent driver. Thick mucus and swollen tissue can block the eustachian tube during a sinus infection, and chronic rhinitis, allergic or not, keeps the lining inflamed for months at a time. If allergies are part of your picture, it helps to understand how allergies and sinusitis feed each other.

Eustachian tube dysfunction treatment, step by step

Dr. Bichey’s rule is to fix whatever is swelling the tube before doing anything to the tube itself. Most patients improve at one of these first steps.

Home measures to unblock the eustachian tube

Swallowing, yawning and chewing gum all open the tube briefly. A gentle Valsalva maneuver (pinch your nose, close your mouth and exhale softly) can push air in, but blowing hard can injure the ear. Autoinflation devices such as Otovent, a small balloon you inflate through one nostril, work the same way. Saline thins mucus near the tube’s opening, and ISC’s guide to nasal saline for sinusitis covers technique.

Flonase and other nasal sprays for eustachian tube dysfunction

Fluticasone (Flonase) is the spray most people reach for, and it makes sense when allergies or sinus inflammation are behind the blockage. The evidence for steroid sprays alone is weaker than most people assume. In a 91-patient randomized trial summarized by American Family Physician, triamcinolone spray did no better than placebo at improving ear pressure tests. Dr. Bichey uses a steroid spray to calm the nose, not as a cure for the ear, and explains how Flonase treats sinus inflammation when he prescribes it.

Be careful with decongestants. Cleveland Clinic advises asking a provider before taking pseudoephedrine for ETD, because it can sometimes make symptoms worse.

Treat the trigger

If your ears plug up every season, allergy testing that starts with a full nasal exam can pin down the cause. Recurrent sinus infections or a CT showing blocked sinuses call for chronic sinusitis treatment first, since the ear won’t settle while the sinuses stay inflamed.

Flying and other pressure changes

A plane’s descent is the hardest test for a eustachian tube that’s already swollen. Cabin pressure rises faster than the tube can equalize, and you can land with sharp pain, muffled hearing or ringing that lingers for days. With an active cold or sinus infection, rescheduling is the safest choice, and this explainer on why flying with a sinus infection hurts covers the mechanics. If you have to fly, swallow often during descent and stay awake for landing. If every flight leaves your ears plugged for days, bring it up at your visit.

When eustachian tube balloon dilation makes sense

Eustachian tube balloon dilation is the next step when symptoms last for months despite treating the nose. The AAO-HNS consensus statement limits it to adults 18 and older with obstructive ETD, and it calls for nasal endoscopy and tympanometry (a quick eardrum pressure test) as part of the workup. A patulous tube rules it out.

What happens during the procedure

The nose is numbed, a small balloon catheter is guided through the nostril to the tube’s opening, and the balloon is inflated for about two minutes. Nothing is cut or left behind. Cleveland Clinic’s procedure guide puts it at 10 to 15 minutes, with a stuffy, sore nose for a day or two afterward. Dr. Bichey’s own walkthrough of what to expect from eustachian tube dilation covers aftercare. ISC performs eustachian tube treatments in the office under local anesthesia. If chronic sinusitis is part of the problem, in-office balloon sinuplasty may belong in the same plan.

What the evidence shows

In a randomized trial of 211 adults published in The Laryngoscope in 2018, Poe and colleagues found eardrum pressure tests normalized at six weeks in 51.8% of balloon dilation patients, compared with 13.9% of patients on medical therapy alone. Symptom scores normalized in 56.2% versus 8.5%, with no serious device-related complications. The UK’s NICE guidance on balloon dilation for ETD rates the safety and efficacy evidence as adequate to support its use. Rare risks include nosebleeds, infection, air trapped under the skin and, very rarely, injury to the carotid artery, which runs near the tube.

Balloon dilation vs ear tubes

Ear tubes (tympanostomy tubes) are the other procedural option. A tiny tube placed through the eardrum bypasses the eustachian tube and vents the middle ear, and Cleveland Clinic notes it provides ventilation for up to a year. Tubes work well for fluid that won’t drain, but they leave the eustachian tube as it was.

Balloon eustachian tube dilation works on the tube itself and leaves the eardrum intact. For adults whose main complaint is pressure and fullness, Dr. Bichey generally starts with dilation and reserves tubes for persistent fluid or patients who can’t have it. This comparison of ear tubes vs eustachian tube dilation walks through the tradeoffs.

Frequently asked questions

How long does eustachian tube dysfunction last?

ETD from a cold usually clears in one to two weeks. When allergies or sinus disease are the cause, it can last months until that inflammation is treated.

My ear won’t pop and I’ve tried everything. What now?

If swallowing, a gentle Valsalva, saline and a few weeks of steroid spray haven’t helped, see an ENT. A scope of the nose and a tympanogram show whether the tube is blocked, stuck open or not the problem at all.

Is Flonase good for eustachian tube dysfunction?

It helps when allergies or sinus swelling are the cause. Trial evidence for steroid sprays alone in ETD is weak, so if a few weeks of daily use hasn’t changed anything, have the cause evaluated.

Getting your ears back to normal

Most eustachian tube dysfunction treatment never gets past the nose: control the allergy or clear the sinus infection, and the ear follows. When it doesn’t, and your ears have stayed plugged for months, an exam can show whether balloon dilation is the right next step. Schedule a visit with Dr. Bichey at Indiana Sinus Centers in Carmel or Fort Wayne to find out what’s blocking yours.

Ragweed allergy symptoms in Indiana start in mid-August, peak in mid-September, and keep going until the first hard frost, which usually arrives in late October. That is 10 weeks or more of sneezing, clear drainage and sinus pressure, and it is why so many Hoosiers who felt fine in July are still reaching for tissues at Halloween.

The trouble is that the same 10 weeks are long enough for a plain allergy to turn into something else. Below, Dr. Bichey walks through how to recognize ragweed, how to tell it apart from a sinus infection, what treatment works in October, and when fall allergies have crossed the line into chronic sinusitis.

When ragweed season runs in Indiana

Indiana’s ragweed season typically runs from mid-August until the first frost, with peak counts in early to mid-September and high counts for several weeks after. Ragweed grows in ditches, field edges and vacant lots across the state, and a single plant can release about 1 billion pollen grains in one season.

The pollen is light enough to travel for miles on a warm, windy afternoon, so living in Carmel or Fort Wayne rather than next to a soybean field does not protect you. Counts are highest in the morning and on dry, breezy days, which is a useful rule for scheduling runs and yard work. You can check the daily count on the Indiana sinus forecast before you head out.

Two other fall triggers stack on top of ragweed in Indiana. Combine harvest kicks up field dust and mold spores from September through November, and wet leaves on the ground release more mold once they start to break down. For a sinus that is already inflamed by ragweed pollen, that extra load is often what tips congestion into pressure and pain.

Ragweed allergy symptoms versus a fall sinus infection

Ragweed hay fever itches. A sinus infection hurts. That is the fastest way to separate them, and it holds up more often than people expect.

Classic ragweed allergy symptoms are sneezing fits, an itchy nose, throat or roof of the mouth, watery and itchy eyes, and a runny nose with thin, clear drainage. Symptoms flare within minutes of going outside and ease indoors with the windows shut. There is no fever. Ragweed allergies also make many people wheeze or cough more, because the pollen reaches the lower airway as well.

A sinus infection looks different. Drainage thickens and turns yellow or green, pressure settles over the cheeks, forehead or between the eyes, and the upper teeth may ache. Smell drops off. Fatigue and a low fever are common. Timing matters too: ENT guidance calls for an evaluation when discolored drainage and blockage last more than 10 days, or when a cold improves and then gets worse again. That second pattern, sometimes called the 10 to 14 day rule, is the most reliable sign that a bacterial infection has taken over.

The two conditions overlap in the fall because allergic swelling narrows the sinus openings, mucus backs up, and bacteria grow in the trapped fluid. If you want a deeper symptom-by-symptom comparison, Dr. Bichey covers it in his guide to allergies versus a sinus infection.

The foods that make ragweed worse

If a slice of cantaloupe makes your mouth itch in September, that is ragweed too. Proteins in certain raw fruits and vegetables look enough like ragweed pollen that the immune system reacts to both, a pattern called oral allergy syndrome. The ragweed allergy foods to avoid, at least raw, are bananas, cantaloupe, honeydew, watermelon, cucumber, zucchini, white potato and sunflower seeds.

The reaction is usually limited to itching or mild swelling of the lips, mouth and throat, and it fades within minutes. Peeling or cooking the food typically prevents it, because heat breaks down the protein. A reaction that spreads beyond the mouth or involves trouble breathing is not oral allergy syndrome and needs emergency care.

Ragweed allergy treatment that still works in October

The best ragweed allergy treatment starts two weeks before the season, but allergies in October still have weeks of pollen ahead of them, so a late start is worth it. Here is the order Dr. Bichey recommends.

Begin with a daily intranasal steroid spray. Fluticasone and its relatives control sneezing, congestion and drainage better than any pill, and they take several days to reach full effect, so use them every day rather than only on bad mornings. Dr. Bichey covers what the spray can and cannot do in his guide to using Flonase for sinusitis.

Add a non-drowsy antihistamine for ragweed allergy on high-count days. Cetirizine, fexofenadine and loratadine all work; the first-generation options such as diphenhydramine cause more sedation and dry the sinuses, so skip them. Rinse with saline irrigation after you come inside in the evening, which physically washes pollen off the nasal lining before it has a chance to trigger overnight congestion.

Then cut exposure. Keep car and bedroom windows closed, shower and change clothes after yard work, and run a HEPA filter in the bedroom. Dr. James Atkins lays out a similar step-by-step approach to managing allergic rhinitis with medication, home controls and immunotherapy.

Immunotherapy for next year

If this is your third or fourth bad fall, treat the cause rather than the symptoms. Allergy testing confirms that ragweed, and not mold or dust mites, is driving the problem, and testing also matters when allergies are feeding chronic sinusitis. Allergy shots or under-the-tongue allergy drops retrain the immune system over three to five years, and the ragweed tablet has to be started at least 12 weeks before the season, which means a decision by May.

When fall allergies turn into chronic sinusitis

Allergies by themselves rarely explain facial pain that is still there at Thanksgiving. If sinus pressure, thick drainage and reduced smell continue for 12 weeks or more, you have met the ENT definition of chronic sinusitis, and the allergy is probably only part of the picture. Untreated allergic swelling can keep the sinus outflow tracts shut long enough that allergic sinusitis becomes a chronic condition, especially in people with a family history of allergies.

Three signs point to a structural problem rather than a seasonal one. The first is a sinus infection every fall, or more than three in a year. The second is a response to antibiotics that fades within a couple of weeks. The third is congestion that stays on one side. Dr. Aaron Feinstein makes the same point about sinusitis that will not go away: once symptoms outlast the trigger, something is blocking drainage.

At that point, Dr. Bichey orders a sinus CT, usually after the acute flare has settled so the scan shows the baseline anatomy rather than a temporary infection. His article on reading a normal versus abnormal sinus CT explains what he looks for. If the openings are narrowed, in-office balloon sinuplasty widens them in the office under local anesthesia, and for patients whose main complaint is a constantly running nose, RhinAer calms the nerve that drives it. Allergies still get treated afterward, but the sinuses finally have room to drain.

Frequently asked questions

When does ragweed season end in Indiana?

Ragweed season in Indiana ends with the first hard frost, which typically falls in late October in central Indiana and somewhat earlier in the northern part of the state. Pollen counts drop sharply after a frost, but mold spores from leaves and harvest dust can keep sinus symptoms going into November.

Can ragweed cause a sinus infection?

Not directly, but it sets one up. Allergic swelling narrows the sinus openings and traps mucus, and bacteria grow in the trapped fluid. Thick, discolored drainage and facial pain that last more than 10 days during ragweed season point to an infection on top of the allergy.

Is it too late to start allergy medicine in October?

No. A daily intranasal steroid spray reaches full effect within days, and Indiana’s ragweed season usually has three to four weeks left in early October. Starting now also reduces the chance that lingering inflammation turns into a sinus infection after the frost.

Ragweed will come back next August. Your sinus problem does not have to.

If this fall feels like every other fall, with symptoms that drag past the frost, antibiotics that only buy a few weeks, or pressure that never fully lifts, the problem is probably no longer just ragweed. Dr. Bichey sees patients at Indiana Sinus Centers in Carmel and Fort Wayne, and most fall sinus patients can be evaluated, scanned and, where appropriate, treated in the office without a hospital visit. Schedule a sinus evaluation and get ahead of next year’s season.