Asthma and Allergic Disease

Submitted by Muriel Langouet-Astrie, MD, Allergy Asthma Center

In May, do as you please! This is not true for 50 million Americans. Allergies are the 6th leading cause of chronic illness in the US with an annual cost in excess of $18 billion. Asthma and allergic disease such as allergic rhinitis (hay fever), food allergy and eczema are common for all age groups in the US.

Some Statistics

There is an increase in the prevalence of allergies and asthma and many factors have been suspected of playing a role. The hygiene hypothesis suggests that we have “sterilized” the playground of our children and that they are not exposed to germs that will stimulate their immune system to differentiate between harmful from non-harmful. In rural areas, our children are more likely than the city children to be exposed to favorable elements. Antibiotic use may also play a role; as the early use of antibiotics increases, so do allergies. Increased obesity in general has been suggested as a contributing factor for the increase in asthma prevalence as well as lack of sun or vitamin D, which is essential for lung and immune system development.

In the US, roughly 7.8% of people 18 and over have hay fever 1. Worldwide, allergic rhinitis affects 10-30% of the population. The rise in prevalence of allergic diseases has continued in the industrialized world for more than 50 years. Sensitization rates to one or more common allergens among school children are currently approaching 40-50% worldwide 2. In 2012, 10.6% children reported respiratory allergies in the past year 3.

Nasal Allergies or Hay Fever

It is estimated that more than 10 million office visits annually are related to allergic rhinitis. In 2012, 7.5% adults were diagnosed with hay fever in the past 12 months 4, and 9.0% or 6.6 million children reported hay fever in the same amount of time 5.

Patients are going to complain of rhinorrhea, sneezing, nasal congestion, itchy nose or palate, ear popping, Eustachian tube dysfunction and possibly facial discomfort. There is fatigue and difficulty concentrating in all ages, including children as they cannot rest well, and some suggest that this can contribute to poorer results in school.

To find the causative allergens one has to do either skin testing or RAST testing. One needs to know that skin testing is more sensitive and less expensive than RAST testing.

There are quite a few allergens. Seasonal examples are trees, grass and weeds and this encompasses a time period from spring to fall. Perennial allergens like dust mites, molds, pets and cockroaches are year-round.

Avoidance of the allergen(s) is always the first step, but one knows that in a rural area avoiding outdoors allergens is far from feasible. Pollen can also travel many miles, so cutting the trees down in your yard (!) is not going to solve anybody’s problem.

Medications are the second step in order to relieve the patient’s complaints. Using antihistamines and inhaled corticosteroids are the main agents that one employs to tackle the inflammation created by the allergy cascade. Then one can add other medications such as leukotriene modifiers, nasal saline, and oral decongestants. One wants to make sure a patient does not use a nasal decongestant due to their severe risk of rebound rhinitis. (I once had patient who used Afrin every hour to be able to breathe.)

BUT the only therapy that cures the abnormal immune response is immunotherapy (allergy shots), which will help reduce hay fever symptoms in about 85% of people with allergic rhinitis. It does involve injecting the allergens subcutaneously into the arm. That process involves two phases; one is the build-up with weekly shots and once the maintenance level is reached, the patient will receive maintenance shots monthly.

There is also sublingual immunotherapy that involves a dissolving tablet (kept under the tongue until it is dissolved). One has to take it daily a few months prior to the beginning of the allergen season and for the duration of the season. This is the only FDA approved form of sublingual immunotherapy in the USA. Currently we do have sublingual immunotherapy for the following: grass, ragweed and (this year) house dust mites. The drawback is that it does not help patients with multiple seasonal or perennial allergies.

Because sublingual immunotherapy is limited, subcutaneous immunotherapy is the best choice at this moment for patients with multiple sensitivities. The starting age is at the discretion of the physician, but one prefers a child that has the communication skills to report signs of a potential reaction to the shot. The more the child is involved in the decision making, the better the outcome of the therapy will be for everybody.

Ocular Allergies

Itchy, watery, red and swollen eyes are not very pleasant spring salutations. Skin testing or RAST testing can help determine causative allergens.

To alleviate the discomfort one can use ophthalmic drops, but the problem is finding the one that works the best for the patient and that might be covered by insurance. Striving to control the symptoms with antihistamine and OPH drops as well as nasal spray is the goal, but if the ocular symptoms go untreated or uncontrolled then steroidal ocular drops can be prescribed by an ophthalmologist.

Once again the cure will be achieved with immunotherapy – either subcutaneous or sublingual.

Asthma

This is the unfair player. 7.7% of all people in the US have asthma, which represents 25 million people. 6.3% of these are children.

Asthma is one of the leading serious chronic illnesses among children in the US, and more than 3,600 Americans die each year from asthma. Asthma accounts for around 14 million days of absence from school and is the third ranking cause of hospitalization for children under the age of 15. It costs approximately $80 billion per year for detection and therapy.

Antibiotic exposure during the first 6 months of life was significantly associated with the major categories of allergic diseases as well. Infants who received antibiotics during the first 6 months of life had adjusted hazard ratios (aHRs) of 2.09 (95% CI, 2.05 – 2.13) for asthma, 1.75 (95% CI, 1.72 – 1.78) for allergic rhinitis, 1.51 (95% CI, 1.38 – 1.66) for anaphylaxis, and 1.42 (95% CI, 1.34 – 1.50) for allergic conjunctivitis.

At the 2018 UVA Swineford Allergy Conference, one speaker reported on her research involving pregnant women receiving folic acid. One of her hypotheses is that it might contribute to asthma later on in life. One would have to do more research as how long folate has to be supplemented to prevent neural tube defects (which might be only for the first few months of pregnancy). A UVA fellow reported the impact of fresh food deserts where unavailability of fresh food might be increasing the risks of asthma. Living farther than a mile from a grocery store was associated with 25% higher odds of having asthma, compared to children who did not live in a food desert. Once again, finding the allergens that trigger asthma exacerbation is very important.

Asthma therapy has been defined as “step up and down” therapy. ACT scores and spirometry with or without full pulmonary function tests help adapt the therapy to the patient.

Hospitalization for asthma seems to rise after school starts, as weed pollination intensifies, and when patients have stopped their asthma medications during the summer. Testing asthmatics once their asthma is controlled will help find out the role of allergens in exacerbation. If allergens are playing a role, one will have to follow with avoidance therapy and immunotherapy if indicated.

Studies have shown that immunotherapy can reduce the development of asthma in children with seasonal rhinoconjunctivitis 6. Before the start of immunotherapy, 20% of the children had mild asthma symptoms during the pollen season(s). Among those without asthma, the actively treated children had significantly fewer asthma symptoms after 3 years as evaluated by clinical diagnosis (odds ratio, 2.52; P <.05). Methacholine bronchial provocation test results improved significant in the active group (P <.05). Conclusion: immunotherapy can reduce the development of asthma in children with seasonal rhino-conjunctivitis.

Food Allergies 

Approximately 6% of 0-2 YO; 9% 3-5 YO; 8% of 6-10 YO; 8% of 11-13 YO; 8.5% of 14-18 YO have a food allergy; 38% have a severe reaction to food, and around 30% have multiple food allergies 7. Food allergy incidence is increasing.

Many patients confuse food allergy and food intolerance. One can be diagnosed with food intolerance if they can tolerate the food one day and not the other. Food allergy, however, would manifest itself within the 4 hours after ingestion, except for red meat food allergy which could be as late as 6 hours. The major allergenic foods represent more than 85 % of food allergy. 11% are allergic to more than one food. In Children they are (by decreasing order) milk, egg, peanuts, tree nuts, soy/wheat, fish, shellfish, and sesame. In Adults they are shellfish, tree nuts, peanuts, milk, soy/wheat, egg, fruits, and vegetables.

Cross reactivity between foods:

  • Fish have a 50% risk of cross reacting to same family (salmon, tuna)
  • Shellfish do cross react to other shellfish in 38-75%, but do not with mollusks (oyster, scallops, and mussels)
  • Tree nuts cross react in 15 to 40%
  • Grain has only a 25 % cross reaction within the same family
  • Legumes cross react in a minimum of 5%

Symptoms involve major systems (skin, GI, respiratory, cardiovascular). The diagnosis is made with the medical history and skin testing / RAST testing. If negative, the Predictive Positive value of a patient without food allergy is around 95%. If positive, there is a 50% chance of a false positive. It is then confirmed by controlled oral food challenge tests.

Persistence is more likely to occur with early age of onset and diagnosis or presence of other co-morbid allergic diseases (allergic rhinitis, asthma and eczema). Tolerance will be suggested by a low or reducing sIgE (specific immunoglobulin E), not by skin testing.

Oral allergy syndrome is often time seen in summer with weeds such as ragweed and mugwort. The symptoms are rapid onset mouth itching, burring or swelling by fresh fruits or vegetables in patients with allergic rhinitis. Ragweed cross reacts with cantaloupe, honeydew, watermelon, cucumber, zucchini and banana. Mugwort cross reacts with celery, carrot, parsley, bell pepper, garlic onion mustard, cabbage and broccoli. The reaction will less likely present itself if the food is cooked as it is generally heat labile.

Please remember to teach and verify your patient remembers how to use their EpiPen. Also remember, EpiPens are expensive- there are coupons available online for generic and non-generic formulas.

Stinging Insects

Spring and summer are also the seasons of stinging insects, so please do remember to tell your patients to avoid crossing paths with hymenopteras. For those with allergic reactions, make sure they have their EpiPen, know how to use it, and have it with them at all times.

Happy and healthy spring and summer to all!

Sources:

  1. Summary Health Statistics for U.S. Adults: National Health Interview Survey, 2010. By Jeannine S. Schiller, M.P.H., Jacqueline W. Lucas, M.P.H., Brian W. Ward, PhD and Jennifer A. Peregory, M.P.H., Division of Health Interview Statistics.
  2. World Health Organization. White Book on Allergy 2011-2012 Executive Summary. By Prof. Ruby Pawankar, MD, PhD, Prof. Giorgio Walkter Canonica, MD, Prof. Stephen T. Holgate, BSc, MD, DSc, FMed Sci and Prof. Richard F. Lockey, MD.
  3. Summary Health Statistics for U.S. Children: National Health Interview Survey, 2012, table 2.
  4. Summary Health Statistics for U.S. Adults: National Health Interview Survey, 2012, table 3, 4.
  5. Summary Health Statistics for U.S. Children: National Health Interview Survey, 2012, table 2.
  6. J Allergy Clin Immunol. 2002 Feb;109(2):251-6.
  7. Gupta, R, et al. The Prevalence, Severity and Distribution of Childhood Food Allergy in the United States. Pediatrics 2011; 10.1542/ped.2011-0204.