Guidelines on Diagnosis and Management of AsthmaContents
The four main components of airflow obstruction in asthma are:
When asthma begins in childhood it is frequently associated with atopy, which is the genetic susceptibility to produce IgE to common environmental allergens. Mast cells and other airway cells are sensitized and become activated when they encounter specific antigens. In children with wheezing during a viral infection, allergy or a family history of allergy is the strongest associated factor with recurrent asthma throughout childhood.
Although asthma occurs most commonly in children, it can also occur later in life. Adult-onset asthma can be associated with atopy. However, there can be also other causes of asthma. Some adults develop asthma without IgE antibodies to allergens. These adults often have coexisting sinusitis, nasal polyps and aspirin or NSAID allergies. Occupational exposures to materials like plastic resins, biological enzymes, animal products and wood dusts can also cause asthma.
Alternative diagnoses should always be excluded. The physician should look for a history of wheezing, recurrent cough, particularly worse at night, recurrent shortness of breath, or recurrent chest tightness. These symptoms may occur or worsen with exercise, viral infection, animals, smoke, pollen, mold, strong emotional expression, menses, and airborne chemicals or dust. Physical exam should include a lung exam for wheezing, examination for nasal polyps or allergic rhinitis and skin exam for atopic dermatitis. Spirometry should be obtained on all patients in whom a diagnosis of asthma is suspected.
An example of an Action Plan:
Sample Asthma Action plan My best peak flow: 40 Green zone peak flow: 40 to 30 (80 to 100% of my best peak flow) Action: Take your normal medication Yellow zone peak flow: 30 to 20 (50 to 80% of my best peak flow) Action: Take your quick-relief medication now ( 2 puffs of albuterol ) Red zone peak flow: less than 20 (less than 50% of my best peak flow) Action: Take your quick-relief medication now ( 2 puffs of albuterol ) Take 40mg of prednisone Call your doctor now!
Irritants: Tobacco SmokeAsthma patients should avoid exposure to environmental smoke. Tobacco smoke is the most important environmental irritant and plays a major role in both childhood and adult asthma. Studies have shown asthma patients exposed to tobacco smoke have decreased pulmonary function and need more medications as compared to asthmatics not exposed to smoke.
Irritants: Air PollutionAsthma patients should avoid exercise or exertion when pollution levels are high. Increased levels of ozone, sulfur dioxide and nitrous dioxide can cause asthma exacerbations.
Animal AllergensAll warm blooded animals can produce urine, feces, dander and saliva that can cause allergic reaction. If a patient appears to have a sensitivity to animal allergens then the most appropriate measure is removal of the animal. If this is not possible then the animal should be kept out of the patient's room, the patient's bedroom door should be kept closed when possible and the pet should be kept away from any upholstered furniture.
House-dust MitesHouse-dust mites usually occur in areas of high humidity or areas where moisture is added to the indoor air. They occur in mattresses, pillows, carpets, upholstery, bed covers and toys. Control measures include allergen impermeable pillow and mattress covers, washing sheets and blankets weekly in hot water, reduction of indoor humidity (if possible) and carpet removal from the bedroom (if possible).
Cockroach allergensSensitivity to cockroaches is common in asthmatics who live in the inner city. Measures to control cockroach infestation should be taken in sensitive individuals.
Indoor moldsIndoor fungi are more common in areas of high humidity.
Outdoor AllergensIn some patients worsening of symptoms at certain times of year an correlate with certain types of allergens. Typical patterns include:
Gastroesophageal RefluxGERD can cause worsening of asthma, especially nocturnal symptoms. Any patient with persistent asthma and heartburn symptoms should be treated for reflux with medical management (either behavioral changes or h2 blockers).
Aspirin SensitivityAdult Patients with asthma should be questioned about episodes of bronchospasm associated with ingestion of aspirin or other NSAIDs. If a reaction has occurred patients should be warned about the dangers of a fatal exacerbation with use of these drugs. Patients with severe asthma or nasal polyps should also receive counseling regarding the potential of NSAIDs to cause a fatal exacerbation. Safe alternatives include acetaminophen and salsalate.
Sulfite SensitivityPatients with sulfite sensitivity will have asthma symptoms after drinking beer, wine, dried fruits, processed potatoes or shrimp. Patients should be advised to avoid foods containing sulfites.
Beta BlockersNon-selective beta blockers can cause bronchospasm and exacerbate asthma in susceptible individuals. Even non-selective beta-blocker ophthalmic solutions can have systemic absorption and cause bronchospasm. If use of a beta-blocker is desired then asthma patients should be given a cardio-selective beta blocker
Allergic Rhinitis/SinusitisBoth allergic rhinitis and sinusitis can cause worsening of asthma symptoms. Patients with persistent asthma and allergic rhinitis should be treated with intranasal corticosteroids. Antihistamines and decongestants may improve AR symptoms but will not improve asthma symptoms like a corticosteroid.