Medical Care
The goals of treatment are to minimize symptoms, improve quality of life, decrease need for urgent care or hospitalizations, normalize pulmonary function test results, and decrease the inflammatory process that leads to airway remodeling. For this discussion, treatment is divided into pharmacotherapy, environmental control, allergen immunotherapy, antibodies against IgE, and education.
1. Pharmacotherapy
The most important facet of medical care is the use of anti-inflammatory medication (usually inhaled glucocorticoids) in patients at all stages beyond mild intermittent asthma. These medications improve the long-term outcomes for children with asthma and do not appear to have significant adverse effects at moderate doses (eg, on growth, bone density, eyes, adrenal sufficiency). Unfortunately, in some series, fewer than half the patients admitted to the hospital for asthma were receiving the recommended anti-inflammatory medications.
NHLBI guidelines suggest that initial medical care should be aggressive to rapidly gain control and then should be tapered as tolerated.
Severe exacerbations require standard care that includes supplemental oxygen (goal PaO2 >60 mm Hg, arterial oxygen saturation >90%), nebulized medications, intravenous fluids, and even noninvasive or invasive ventilatory support. Heliox (helium-oxygen gas mixture) is an option but has not been systematically shown to be helpful.
Antibiotics offer no added benefit during an asthma exacerbation.
In emergency situations, nebulized magnesium sulfate during acute asthma attacks—when added to short-acting beta-2 agonists—may improve pulmonary function and reduce admissions, based on a limited number of studies.
All patients should receive assistance with quitting tobacco use. While smoking cessation is essential for a number of reasons, it particularly appears to increase corticosteroid responsiveness in patients with asthma.
All patients should receive an annual flu shot. A pneumococcal pneumonia vaccination is not required unless indicated based on age (ie, >65 y). Asthma symptoms do not increase after these shots because the antigens in the vaccinations are not alive.
Evaluating and treating patients for associated conditions (eg, rhinitis, GERD, sinusitis) can be important components of therapy. In one study, treating the GERD symptoms of patients with asthma with a proton pump inhibitor for 6 months reduced asthma exacerbations and improved quality of life but did not improve asthma symptoms or pulmonary function or reduce albuterol usage.
In addition, see Staging and Medication.
2. Environmental control
Allergen avoidance takes different forms depending on the specific allergen size and characteristic. Improvement in symptoms after avoidance of the allergen may take 1-6 months.
Efforts should focus on the home, where 30-60% of time is spent. Patients should clean and dust their homes regularly. If patients cannot avoid vacuuming, they should use a face mask or a double-bagged vacuum with a high-efficiency particulate air filter. Consideration can be given to moving to a higher floor in the house (less dust and mold) or different neighborhood (fewer cockroaches) if possible. Active smoking and exposure to passive smoke must be avoided. Room air ionizers have not been proven effective to help persons with chronic asthma and the generation of ozone by these machines may be harmful to some. Other factors related to the home include the following:
Dust mites (Dermatophagoides pteronyssinus or "dead skin feeders," size 30 µm): The primary allergen is an intestinal enzyme on fecal particles. The allergen settles on fabric because of its relatively large size; therefore, air filtration is not as important. Measures to avoid dust mites include using impervious covers (eg, on mattresses, pillows, comforters), washing other bedding in hot water (130°F [54.4°C] most effective), removing rugs from the bedroom, limiting upholstered furniture, reducing the number of window blinds, and putting clothing away in closets and drawers. Minimize the number of soft toys, and wash them weekly or periodically put them in the freezer. Decrease room humidity (<50%); this is difficult in hot, humid climates.
Cats and other animals (dander or saliva, urine, or serum proteins, size 1-20 µm): Because of its small size, this allergen is predominantly an airborne indoor allergen. Avoidance involves removing animals from the home (or at least from the bedroom), using dense filtering material over heating and cooling duct vents, and washing cats and dogs as often as twice weekly.
Cockroaches (size 30 µm): Twenty percent of homes without visible infestation still produce sensitizing levels of allergen. Successful allergen elimination measures are difficult, especially in poor living conditions. To control cockroaches, exterminate and use poison baits and traps, keep food out of the bedroom, and never leave food out in the open.
Wet molds (size 1-150 µm): Avoidance includes keeping areas dry (eg, remove carpets from wet floors), removing old wallpaper, cleaning with bleach products, and storing firewood outdoors.
Pollen (size 1-150 µm): Avoidance includes closing windows and doors, using air conditioning and high-efficiency particulate air filters in the car and home, staying inside during the midday and afternoon when pollen counts are highest, wearing glasses or sunglasses, and wearing a face mask over the nose and mouth when mowing the lawn. In addition, consider increasing medications preseason and vacationing out of the area.
3. Allergen immunotherapy
Repeated injections of small doses of allergen have been used for more than 90 years to treat allergic rhinitis. This treatment is clearly effective, and positive effects may persist even years after treatment is stopped. This treatment is also considered mandatory for life-threatening bee and wasp sting reactions. The role of repeated allergen injections in patients with asthma has been more controversial, ranging from a relative indication to no indication. Benefit has been shown in individuals with allergy-induced asthma.
- Allergen immunotherapy should be considered if specific allergens have a proven relationship to symptoms; the individual is sensitized (ie, positive skin test or RAST findings); the allergen cannot be avoided and is present year-round (eg, industrial); or symptoms are poorly controlled with medical therapy, and a vaccine to the allergen is available. As discussed above, this treatment is especially useful if asthma is associated with allergic rhinitis
- INJ HISTAGLOBE : 1 AMP. EVERY WEEK FOR 3 WEEKS. THEN 4TH AFTER 6 WEEKS AND THEN EVERY 6 MONTHS FOR FEW YEARS.
- Antibodies to IgE antibody - Omalizumab
Omalizumab (Xolair) was approved by the FDA in 2003 for adults and adolescents (>12 y) with moderate-to-severe persistent asthma who have a positive skin test result or in vitro reactivity to a perennial aeroallergen and whose symptoms are inadequately controlled with inhaled corticosteroids.
This is a humanized murine IgG antibody against the Fc component of the IgE antibody (the part that attaches to mast cell surfaces). Use of this antibody prevents IgE from binding directly to the mast cell surface, thereby preventing cell degranulation.
Therapy has been shown to decrease IgE antibody levels by 99% and cell receptor sites for IgE antibody by 97%. This decrease, in turn, is associated with reduced histamine production (90%), early-phase bronchospasm (40%), and late-phase bronchospasm (70%) and a decrease in the number, migration, and activity of eosinophils. levels drop quickly and remain low for at least a month.
This therapy is also effective for allergic rhinitis.
Multiple phase 3 trials show that, compared to placebo injections, treatment is associated with larger median inhaled steroid dose reduction (83% vs 50%), higher percentage of discontinuation of inhaled steroids (42% vs 19%), and fewer asthma exacerbations (approximately 15% vs 30%). Quality of life and use of rescue inhaler and the emergency department may also be improved. Omalizumab is approved for reduction of exacerbations.
Adverse effects are rare and include upper respiratory infection symptoms, headache, urticaria (2%) without anaphylaxis, and anaphylaxis (0.1%). Transient thrombocytopenia has also been noted but not in humans. Antibodies are formed against the anti-IgE antibody, but these do not appear to cause immune-complex deposition or other significant problems. To date, decreased IgE levels have not been shown to inhibit one’s ability to fight infection (including parasites). Registration trials raised a question of increased risk of malignancy, but this has not been seen in the postmarketing data.
Omalizumab is given by subcutaneous injection every 2-4 weeks based on initial serum IgE level and body weight. Patients are usually treated for a trial period lasting at least 12 weeks. Costs may be $12,000/y, so omalizumab is likely to be cost-effective only in patients with severe persistent asthma who have frequent exacerbations requiring hospitalization.
Education: