Allergic Asthma
Overview
Allergic asthma, also known as allergy-induced asthma, is a type of asthma that is triggered by allergens in the environment. It is the most common form of asthma, affecting approximately 60% of all asthma patients. Allergic asthma is characterized by airway inflammation, reversible airway obstruction, and bronchospasm. The condition is typically managed with a combination of avoiding allergens, taking medications to prevent symptoms, and treating attacks when they occur.
Causes
Allergic asthma is caused by an overreaction of the body's immune system to certain substances, known as allergens. Common allergens that can trigger allergic asthma include pollen, dust mites, mold, pet dander, and cockroach droppings. When a person with allergic asthma inhales these allergens, their immune system responds by releasing substances that cause inflammation in the lungs. This inflammation leads to the symptoms of asthma.
Symptoms
The symptoms of allergic asthma are similar to those of other types of asthma, but they are triggered by exposure to allergens. Symptoms can vary in severity and may include:
- Wheezing
- Shortness of breath
- Chest tightness
- Coughing
- Difficulty sleeping due to the above symptoms
Symptoms can be worse at night and early in the morning or in response to exercise, allergen or cold air exposure.
Diagnosis
The diagnosis of allergic asthma involves a combination of a medical history, physical examination, and diagnostic tests. The medical history will involve questions about the patient's symptoms, their frequency and duration, triggers, and any family history of asthma or other allergic diseases. The physical examination will typically include an examination of the lungs and airways.
Diagnostic tests may include:
- Spirometry test: This test measures how much air a person can breathe in and out and how fast they can exhale.
- Allergy tests: These tests can identify the specific allergens that are triggering a person's asthma symptoms.
- Chest X-rays: These can be used to rule out other conditions that may be causing the symptoms.
Treatment
The treatment of allergic asthma involves a combination of medication and allergen avoidance. Medications used to treat allergic asthma include:
- Inhaled corticosteroids: These medications reduce inflammation in the lungs.
- Long-acting beta agonists: These medications help to relax the muscles around the airways.
- Leukotriene modifiers: These medications block the action of certain immune system chemicals that contribute to inflammation in the lungs.
Allergen avoidance involves taking steps to reduce exposure to the allergens that trigger a person's asthma symptoms. This may involve using air filters, regularly cleaning to reduce dust mites, or avoiding outdoor activities when pollen counts are high.
In some cases, immunotherapy (allergy shots) may be recommended. This treatment involves regular injections of small amounts of the allergens that trigger a person's symptoms. Over time, this can help to desensitize the immune system to these allergens and reduce the severity of asthma symptoms.
Prognosis
The prognosis for allergic asthma varies depending on the severity of the condition and how well it is managed. With proper treatment and management, most people with allergic asthma can lead normal, active lives. However, uncontrolled allergic asthma can lead to serious complications, including permanent lung damage and, in rare cases, death.
Epidemiology
Allergic asthma is the most common form of asthma, affecting an estimated 60% of all asthma patients. It can occur at any age, but it most often starts in childhood. It is more common in people who have a family history of asthma or allergies.