Allergies and Asthma
Allergies and Asthma
Don't Overlook The Missing Link
Allergic rhinitis and asthma have increased dramatically over the past 20 years, particularly in developed countries. The prevalence of asthma rose 75% between 1960 and 1994, with hospitalizations and morbidity rates also increasing significantly.1 Asthma is now the most common chronic disease of childhood and allergic rhinitis is the sixth most common chronic disease overall, affecting more than 20% of the U.S. population.2 Further research is needed to understand the interrelationship among allergy and asthma, genetics, indoor allergens and air pollutants, diet, and altered immune system response.3-5
Unfortunately, allergies and asthma are too often considered independently of each other, resulting in incomplete diagnosis or treatment. An estimated 80% of children with asthma and 40% of adults with asthma experience symptoms after exposure to allergic triggers.6 In addition, people affected by allergy are at least three times more likely to develop asthma.7,8 Up to 40% of patients with allergic rhinitis also have asthma.2 For this reason, the National Heart, Lung and Blood Institute (NHLBI) recommends careful evaluation for allergic triggers in patients with asthma.3 Allergic patients should also be monitored for the development of asthma symptoms.
Allergies and asthma are so common that the symptoms can be neglected on the presumption that they are benign. But untreated or undertreated allergic rhinoconjunctivitis can induce chronic nasal inflammation and nasal obstruction with chronic postnasal drainage. This can lead to serious upper and lower airway complications, with asthma being the most life-threatening and probably the most costly. Undertreated asthma can result in permanent remodeling of the airways. Research consistently demonstrates that treatment of allergic rhinitis symptoms is associated with significant relief of asthma symptoms as well.2
Many factors can trigger asthma, including allergies, environmental irritants (smoke, odors, cold air), exercise, viral infections (respiratory syncytial virus, influenza, rhinovirus), aspirin, sulfites and gastroesophageal reflux. Airborne allergies are the strongest predisposing factors for asthma.3 Research proves that exposure to inhalant allergens increases airway inflammation, airway hyperreactivity, medication levels, the frequency of asthma symptoms, and asthma-related deaths.9
Allergic rhinitis is a localized upper respiratory condition characterized by copious clear, watery rhinorrhea; nasal congestion; sneezing; itching of the nose, eyes, ears or palate; and fatigue.4,10 Although asthma is now recognized as an inflammatory disease of the airways, it has been historically viewed as a bronchoconstrictive process. Allergic and non-allergic stimuli trigger both upper respiratory and lower respiratory inflammatory symptoms. Once triggered, the pattern of inflammation is the same from the tip of the nose to the base of the lung.2,3 An allergen stimulus activates mast cells and macrophages that cause release of basophils, eosinophils, epithelial cells, myofibroblasts, neutrophils, platelets and T-lymphocytes. These cells combine with mediators including histamine, lipids, peptides, cytokines and growth factors to produce bronchoconstriction, microvascular leak, mucus hypersecretion, and airway hyperresponsiveness. The patient develops acute symptoms within a few minutes, including rhinorrhea, itching, sneezing, congestion or airflow limitation. These early-phase symptoms tend to subside 20 to 30 minutes after the triggering allergen is removed.3,4
A second, late-phase wave of mediator release can occur approximately 3 to 11 hours after the initial allergen exposure, producing symptoms that can last 24 to 36 hours. This late-phase reaction sets up a potentially chronic inflammation that causes congestion, airflow limitation and fatigue. Chronic inflammation is associated with chronic symptoms as well as complications. A late-phase reaction can lower the symptom threshold for exposure to subsequent allergens, resulting in a "priming" effect.3,4 The priming effect of the late-phase reaction is the source of much confusion for patients, who find it hard to believe that certain allergens (e.g., pets) are the source of their symptoms.
Table 1 outlines the key indicators for the diagnosis of allergic rhinitis. Table 2 lists the indicators for diagnosing asthma. The high incidence of co-morbidity with these conditions and their common pathophysiology support the clinical evaluation of allergies and asthma together. Many patients are so accustomed to their symptoms that very direct questioning is necessary to elicit a symptom history. Many patients "blow their nose and get on with life" and have lived with significant symptoms for many years. Many patients with asthma have never demonstrated wheezy breath sounds, but present with untreated, cough-variant asthma.
The most important step in controlling allergy-induced asthma symptoms is not triggering allergen exposure. Patients may exhibit early-phase or late-phase symptoms, depending on the frequency and duration of the allergen exposure. Many patients do not know some or all of their allergic triggers and may be reluctant to avoid things they are not sure they are allergic to. If symptoms are significant or patients are unwilling or unable to avoid likely triggers, referral and allergy testing are indicated.
There are two categories of allergy testing, skin and in vitro. The relative merits of each are reviewed in Table 3. Test results demonstrate the patient's actual allergies and lead to specific avoidance measures to reduce exposure. The patient gains a clearer picture of the pathway of his own symptoms and the potential value of allergen avoidance. Any patient with persistent asthma who requires daily medication should be evaluated for possible allergies.3
Allergen avoidance measures are the starting point for symptom prevention and management. Sample avoidance measures for high frequency allergy triggers are reviewed in Table 4. Some of these measures are difficult or costly to implement, and patients may resist them. Many prefer to take medication in the hope that their symptoms will be cured in the same way an antibiotic eradicates a bacterial infection. The chronic nature of allergen exposure followed by rhinitis or asthma symptoms can be frustrating for patients of this mindset. If the triggering allergen is a beloved pet or requires major environmental change, patients may be very reluctant to believe you, let alone take steps to avoid the allergen.
Patient education is critical to the effective management of allergies and asthma. Teaching simple allergen avoidance measures, implementing them at home and producing results are time-consuming endeavors. In contrast, prescribing medication requires only a short visit with some brief follow-up. There is no doubt, however, that patient education means the difference between successful allergen avoidance and persistent symptoms with complicated sequelae.
Since patients are likely to forget more than half of what they hear, provide a written plan of care. The key patient education principles to be included are reviewed in Table 5.
Medications for allergy and asthma symptoms are constantly improving. National guidelines for the diagnosis and management of rhinitis provide an excellent algorithm.10 The National Institutes of Health report on asthma diagnosis and management set the standard for current asthma care.3 The guidelines discuss the role of immunotherapy in the management of allergic triggers for asthma that persist during a major portion of the year and when pharmacologic treatment is unsuccessful due to medication or patient issues.
The link between allergic triggers and asthma symptoms cannot be overlooked. Successful identification of allergic triggers for asthma can lead to effective avoidance of triggers and thus better management of symptoms. The high incidence of these chronic symptoms will affect a large number of patients, whether as their presenting complaint or as a coexisting problem. Benign neglect or under-treatment of allergy or asthma symptoms is associated with the development of further complications. At least one of every five people has allergies or asthma. The incidence of allergies or asthma in the patient population presenting with ocular, nasal, throat or lung symptoms may be much higher. Successful identification and treatment of patients with allergic triggers for asthma is essential for conscientious care.
1. Centers for Disease Control and Prevention. Surveillance for asthma United States, 1960-1995. MMWR. 1998;47(SS-1):1-27.
2. Palakanis K, Corren J, Prenner BM. Asthma and allergic rhinitis: how important is the link? Clinical Courier. 1997;16(21):1-8.
3. National Heart, Lung and Blood Institute. Guidelines for the Diagnosis and Management of Asthma, Expert Panel Report 2, Clinical Practice Guidelines. Bethesda, Md.: National Institutes of Health; 1997. Publication No. 97-4051.
4. Philip G, Togias A. Allergic rhinitis: making the diagnosis. J of Resp Dis. 1999;20(8):547-551.
5. Hogate S. Asthma and allergy, disorders of civilization? Q J Med. 1998;91:171-184.
6. Weiss ST, Sparrow D, O'Connor GT. The interrelationship among allergy, airways responsiveness, and asthma. J Asthma. 1993;30(5):329-349.
7. Settipane RJ, Hagy GW, Settipane GA. Long term risk factors for developing asthma and allergic rhinitis: a 23-year follow-up study of college students. Allergy Proc. 1994;15(1):21-25.
8. Meltzer EO. The prevalence and medical and economic impact of allergic rhinitis in the United States. J Allergy Clin Immunol. 1997;99(suppl.):S805-S828.
9. National Heart, Lung and Blood Institute. Highlights of the Expert Panel Report II: Guidelines for the Diagnosis and Management of Asthma. Bethesda, Md.: National Institutes of Health; 1997. Publication No. 97-4051A.
10. International Rhinitis Management Working Group. International Consensus on the Diagnosis and Management of Rhinitis. Allergy. 1994;49:1-36.
11. Wieker TL. Managing asthma with behavior modification. Clinician Reviews. 1999;9(3):65-82.
Barbara Opperwall is a nurse practitioner at Adult and Pediatric Allergy Care in Grand Rapids, Mich.
Key Indicators of Allergic Rhinitis4,10
- Pale to bluish nasal mucosa
- Enlarged, boggy inferior turbinates
- Clear to whitish rhinorrhea
- Transnasal crease
- Pruritis of nose, eyes, ears, palate
- Clear drainage on posterior wall of oropharynx
- Conjunctival erythema
- Dark undereye discoloration (allergic shiners)
- Infraorbital edema
- Mouth breathing
- Family history or presence of atopic conditions (eczema, urticaria)
- Recurrent sinusitis or otitis media
- Seasonal symptoms (pollens)
- Perennial symptoms (mites, molds, animals)
Key Indicators of Asthma3
If any indicator is present, perform spirometry. Spirometry is the basis for asthma diagnosis in patients older than 6.
- Presence or history of wheezing, cough, dyspnea
- Recurrent chest tightness
- Greater than 20% daily variation in peak flow
- Symptoms worse at night
- Symptoms worsen with:
- Strong emotions
- Furry animals
- Strong odors
- Weather changes
- Dust mites Smoke (tobacco or wood)
Comparison of Skin and In Vitro Tests For Allergy3
Results available in an hour
Must avoid antihistamines and many
antidepressants for 3 days to 3 weeks
Risk of systemic reaction
Skin must be clear
Complex technique and materials
IN VITRO TESTING
More false negative test results
Results per lab processing time
Can be performed while patient
continues medication regimen
No risk of systemic reaction
Not affected by extensive eczema
Requires laboratory access
Patient Education for Allergy and Asthma11
-Distinguish true from false beliefs
-Provide unbiased, detailed information
-Inquire about skepticism from family or friends
-Becoming dependent on medications
-Death from severe symptoms
-Medication side effects
Provide A Written Treatment Plan
-Personal allergy and asthma triggers
-Consequences of undertreated symptoms
-How their medications work
-When to use their meds and how to adjust them
-How to self-monitor their symptoms
-Mutual goals for healthy function