Allergic Asthma
Asthma triggered by allergens such as pollen, dust mites, and pet dander
Quick Facts
- Type: Chronic respiratory (airway) condition
- Common triggers: Pollen, dust mites, pet dander, mold
- Key symptoms: Wheezing, cough, chest tightness, breathlessness
- Seek emergency care: Severe breathlessness, reliever not working
Overview
Allergic asthma is the most common type of asthma. In this condition, the immune system overreacts to normally harmless substances called allergens. When an allergen is inhaled, the airways become inflamed, swell, and tighten, and produce extra mucus, making it harder to breathe.
People with allergic asthma often also have other allergic conditions such as hay fever (allergic rhinitis) or eczema. While allergic asthma is a long-term condition, it can usually be well controlled by avoiding triggers, treating allergies, and using prescribed inhalers, allowing most people to live active, normal lives.
Symptoms
Symptoms tend to flare up after contact with an allergen and may include:
- Wheezing (a whistling sound when breathing out)
- Coughing, often worse at night or early morning
- Shortness of breath
- Chest tightness or pressure
Allergy symptoms such as sneezing, a runny or stuffy nose, and itchy, watery eyes often occur alongside the asthma. A severe asthma attack can cause rapid worsening of breathing, difficulty speaking in full sentences, and a reliever inhaler that no longer helps. This is a medical emergency.
Causes
Allergic asthma is caused by an immune response to inhaled allergens. Common triggers include:
- Pollen: From trees, grasses, and weeds, often worse in certain seasons.
- Dust mites: Tiny organisms in bedding, carpets, and upholstery.
- Pet dander: Skin flakes, saliva, and urine from cats, dogs, and other animals.
- Mold spores: Found in damp indoor and outdoor environments.
- Cockroach droppings: A common indoor trigger.
Once the airways are sensitized, other factors such as cold air, exercise, smoke, or respiratory infections can also bring on symptoms.
Risk Factors
- A personal or family history of allergies or asthma
- Other allergic conditions such as hay fever or eczema
- Exposure to allergens, tobacco smoke, or air pollution
- Childhood respiratory infections
- Living or working in environments with high allergen or irritant levels
Diagnosis
Doctors diagnose allergic asthma using a combination of history, breathing tests, and allergy testing:
- Medical history and exam: Reviewing symptoms, triggers, and family history.
- Spirometry and lung function tests: Measuring how much and how quickly you can exhale to detect airway narrowing.
- Allergy testing: Skin prick tests or blood tests identify which allergens trigger your symptoms.
Treatment
Treatment aims to control inflammation, relieve symptoms, and reduce attacks:
- Controller (preventer) inhalers: Inhaled corticosteroids taken daily reduce airway inflammation and are the cornerstone of long-term control.
- Reliever (rescue) inhalers: Quick-acting bronchodilators open the airways during symptoms or an attack.
- Allergy treatments: Antihistamines, nasal sprays, and in some cases allergen immunotherapy (allergy shots or tablets) reduce sensitivity to triggers.
- Additional medicines: Such as leukotriene modifiers or, for severe disease, biologic therapies.
An asthma action plan from your doctor explains daily treatment and what to do if symptoms worsen.
Prevention
- Identify and limit exposure to your specific allergens
- Use allergen-proof bedding covers and wash bedding in hot water to reduce dust mites
- Keep humidity low to limit mold and dust mites
- Avoid tobacco smoke and minimize exposure to pets if you are allergic
- Take controller medication as prescribed, even when feeling well
- Keep your reliever inhaler with you and follow your asthma action plan
When to See a Doctor
See a doctor if you have ongoing wheezing, cough, or breathlessness, or if you need your reliever inhaler more often than usual. Call emergency services or go to the nearest emergency department if you have:
- Severe shortness of breath or struggling to breathe
- A reliever inhaler that does not help or wears off quickly
- Difficulty speaking, eating, or walking due to breathlessness
- Lips or fingertips turning blue or gray
Frequently Asked Questions
What is the difference between allergic asthma and regular asthma?
Allergic asthma is asthma in which symptoms are triggered specifically by allergens such as pollen, dust mites, or pet dander. Non-allergic asthma is triggered by other factors like infections, cold air, or exercise. Many people have a mix of triggers.
What are the most common triggers of allergic asthma?
The most common triggers are pollen, dust mites, pet dander, mold spores, and cockroach droppings. Identifying your specific triggers through allergy testing helps you avoid them and tailor treatment.
Can allergic asthma be cured?
There is no cure, but allergic asthma can usually be very well controlled. Avoiding triggers, treating allergies, and using prescribed controller and reliever inhalers allow most people to lead full, active lives. Allergen immunotherapy may reduce sensitivity over time.
When is an asthma attack an emergency?
An asthma attack is an emergency if you have severe breathlessness, cannot speak in full sentences, your reliever inhaler is not working, or your lips or fingertips turn blue. Call emergency services immediately in these situations.
Do I need to take asthma medication when I feel fine?
Yes, if you have been prescribed a daily controller inhaler. It reduces underlying airway inflammation and helps prevent attacks even when you feel well. Stopping it can allow asthma to worsen.
References
- National Heart, Lung, and Blood Institute (NHLBI). Asthma.
- American Academy of Allergy, Asthma & Immunology (AAAAI).
- Mayo Clinic. Allergies and asthma.
- MedlinePlus, U.S. National Library of Medicine. Asthma.