Severe allergies require a layered approach: the right medications, environmental changes to reduce exposure, and in many cases, long-term treatments like immunotherapy or biologics that retrain or calm your immune system. What works depends on whether you’re dealing with chronic severe symptoms (allergic rhinitis, hives, allergic asthma) or the risk of sudden life-threatening reactions like anaphylaxis. Most people with severe allergies need more than one strategy working together.
Medications That Go Beyond Basic Antihistamines
Over-the-counter antihistamines are where most people start, but standard doses often fall short for severe symptoms. Allergists can prescribe second-generation antihistamines at up to four times the standard dose for conditions like chronic hives that don’t respond to normal treatment. Fexofenadine, cetirizine, and levocetirizine are commonly used at these higher levels. For most patients, even high-dose antihistamines cause minimal sedation, though older first-generation options like hydroxyzine are sometimes added at bedtime when drowsiness is less of an issue.
Nasal corticosteroid sprays are a cornerstone for severe allergic rhinitis. They reduce the underlying inflammation that antihistamines alone can’t fully control. Using a steroid spray daily during allergy season, rather than waiting for symptoms to flare, makes a significant difference. Combination sprays that pair a corticosteroid with a nasal antihistamine deliver faster and broader relief than either ingredient alone.
For severe allergic asthma, inhaled corticosteroids and long-acting bronchodilators form the baseline. But when those aren’t enough, the next step is a class of drugs called biologics.
Biologics for Allergies That Won’t Quit
Biologics are injectable medications that target specific molecules in your immune system responsible for allergic inflammation. Seven are now FDA-approved for asthma, and some are also approved for chronic hives, nasal polyps, and eczema. They’re reserved for people whose symptoms remain poorly controlled despite standard treatments.
Omalizumab (Xolair) was the first and targets IgE, the antibody your body produces in response to allergens. By blocking IgE from triggering histamine release, it reduces airway tightening and allergic reactions across multiple organ systems. It’s approved for allergic asthma, chronic hives, and nasal polyps.
Dupilumab (Dupixent) blocks two inflammatory signals, IL-4 and IL-13, that drive swelling and mucus production. It works across a broader range of allergic conditions, including eosinophilic asthma, moderate-to-severe eczema, and chronic sinusitis with nasal polyps. For people dealing with overlapping allergic diseases, a single biologic can sometimes improve several conditions at once.
Three other biologics target a molecule called IL-5, which activates a specific type of white blood cell that causes airway inflammation. One newer option in this group, depemokimab, is notable because it only needs to be given twice a year, making it the first ultra-long-acting biologic for asthma. Another biologic, tezepelumab, works higher up in the immune cascade and is the only one approved for people whose severe asthma doesn’t fit neatly into allergic or eosinophilic categories.
Biologics are given by injection, typically every two to four weeks (with that one exception). Most people self-inject at home after their initial doses. They’re expensive without insurance, but specialty pharmacies and manufacturer programs often reduce out-of-pocket costs significantly.
Immunotherapy: A Long-Term Fix
Immunotherapy is the closest thing to a cure for environmental allergies. It works by exposing your immune system to gradually increasing amounts of your specific allergens until it learns to tolerate them. The benefits often last years after treatment ends, which sets immunotherapy apart from every other allergy medication.
You have two options: allergy shots (subcutaneous immunotherapy) or tablets and drops placed under the tongue (sublingual immunotherapy). Research comparing the two in children with allergic rhinitis found no significant difference in how well they reduced symptoms or medication use. Both were equally effective at preventing new allergic sensitivities from developing and reducing the risk of progressing to asthma.
The key difference is safety. Sublingual immunotherapy causes significantly fewer treatment-related side effects than shots. Most reactions to sublingual therapy are mild, like itching or tingling in the mouth, while shots carry a small risk of systemic reactions that require monitoring in a medical office. For children especially, sublingual therapy may be the more practical choice.
The tradeoff is time. Immunotherapy typically requires at least 12 months before meaningful improvement, and most allergists recommend continuing for three to five years for lasting results. Shots involve weekly visits initially (tapering to monthly), while sublingual tablets are taken daily at home. It’s a commitment, but for people with severe allergies affecting their quality of life, the payoff of reduced symptoms and less dependence on medications is substantial.
Reducing Allergens at Home
No medication works as well when you’re constantly swimming in the thing you’re allergic to. Environmental control won’t replace treatment, but it can meaningfully lower your symptom baseline.
For dust mite allergies, humidity is the single most important variable. Dust mites thrive in moist environments and struggle to survive when indoor humidity stays below 40 percent. A hygrometer (available for a few dollars) lets you monitor levels, and a dehumidifier can keep problem rooms in range. Wash all bedding weekly in water that’s at least 130°F, which is hot enough to kill mites and break down their allergenic proteins. Encasing your mattress and pillows in allergen-proof covers adds another layer of protection.
Air filtration makes a measurable difference, but filter quality matters. HEPA filters remove 99.97% of particles down to 0.3 microns, capturing pollen, mold spores, pet dander, and dust mite debris. If you’re upgrading your HVAC system’s filter rather than buying a standalone unit, look for a MERV 13 rating. These capture 75% to 85% of the smallest particles (0.3 to 1.0 microns) and up to 90% of slightly larger ones. Filters below MERV 13 let most allergen-sized particles pass through.
For pollen allergies, keeping windows closed during high-count days, showering before bed to remove pollen from your hair and skin, and running a HEPA purifier in your bedroom can reduce nighttime exposure enough to improve sleep quality noticeably.
Emergency Preparedness for Anaphylaxis
If your severe allergies include a risk of anaphylaxis, whether from foods, insect stings, or medications, carrying epinephrine is non-negotiable. Anaphylaxis can cause a dangerous drop in blood pressure, severe throat tightening, shortness of breath, a rapid weak pulse, and loss of consciousness. Symptoms can escalate within minutes.
Epinephrine should be given immediately at the first sign of a severe reaction, injected into the outer thigh. A second dose can be given 5 to 15 minutes later if symptoms don’t improve. Even after symptoms resolve, medical observation is recommended for at least two hours after one dose and four hours after a second dose, because reactions can return.
For people who’ve avoided carrying an auto-injector because of needle anxiety, the FDA has approved neffy, the first epinephrine nasal spray. It’s a single-dose spray administered into one nostril, approved for anyone weighing at least 66 pounds (about 30 kilograms), including children. A second spray can be given in the same nostril using a new device if symptoms persist. It removes the biggest barrier many people cite for not carrying their epinephrine consistently.
Regardless of which form you carry, the most common mistake is hesitating. Epinephrine given early is far more effective than epinephrine given late, and the risks of using it unnecessarily are minimal compared to the risks of untreated anaphylaxis. If you’ve had one anaphylactic episode and don’t yet know your trigger, an allergist evaluation within four to eight weeks can identify the cause and help you build a prevention plan.