Chronic Allergies

Pradeep Sharma MD

Allergic Diseases

INTRODUCTION

Allergic diseases, which include allergic rhinitis, bronchial asthma, anaphylaxis, and atopic dermatitis, are among the leading causes of office visits to the primary care provider. This chapter discusses practical aspects in diagnosing and managing chronic allergic diseases. Asthma is covered in Chapter 55. Urticaria, contact dermatitis, and anaphylaxis are covered in Chapter 48.

PATHOLOGY

Allergic diseases can lead to acute reactions, such as anaphylaxis, and chronic diseases, such as allergic rhinitis, atopic dermatitis, and chronic urticaria. This is because immunoglobulin E (IgE)-mediated reactions are biphasic, involving early-phase responses (anaphylaxis) and late-phase responses. The late-phase response is associated with activation of endothelial cells, with migration to and infiltration of eosinophils and basophils, leading to mediator release and inflammation.

EPIDEMIOLOGY

Allergic diseases affect approximately 25% of all children. The economic implications are enormous, with health care costs approaching $1.2 billion per year. Another $1.2 billion can be attributed to indirect health care costs. Inclusion of associated diseases, such as asthma, chronic sinusitis, otitis media with effusion, and nasal polyps (all of which are associated with allergic rhinitis), bring the cost close to a staggering $10 billion per year (Malone, Lawson, Smith, Arrighi, & Battista, 1997). The incidence of allergic diseases, especially asthma, is rising. The exact cause for this phenomenon is not known. Morbidity and associated direct and indirect health costs can be reduced through better primary care provider, patient, and family education.

Allergic Rhinitis

Allergic rhinitis is defined as multiple symptoms affecting the upper airways, primarily the nose, as a result of inflammation. This response is primarily due to the interaction of IgE antibody with mast cells. It is difficult to distinguish allergic rhinitis from other forms of rhinitis in which IgE antibody may not be involved.

PATHOLOGY

The spectrum of rhinitis is characterized by inflammation. In allergic rhinitis, inflammation is due to release of mediators of allergy from mast cells. This is a result of allergen binding two adjacent IgE antibodies on the surface of mast cells. These mediators consist of histamine, prostaglandins, and leukotreines. Another concept to understand is the priming effect of the nasal airway. Priming of the nasal passage is caused by inflammation of the nasal mucous membranes. This results in sequentially lower doses of triggers (allergens, irritants, physical) producing the same degree of nasal symptoms that occurred after the initial exposure.

EPIDEMIOLOGY

A positive family history for allergies is present in about 50% to 75% of patients. Allergic rhinitis affects 52 to 55 million Americans (20%–25% of the population). It is responsible for more than 11 million office visits annually (Malone et al., 1997). Allergic rhinitis is responsible for up to 2 million lost school days. The cost to society is about $2.7 billion per year. Allergic rhinitis is hence not a trivial disease. Its costs are high, not only in dollar amounts, but also in quality of life, as described by Juniper’s survey (1997) of patients with chronic rhinitis (a majority of whom have allergic rhinitis). In addition to the perception that their health had changed, patients reported that their chronic rhinitis caused changes in their social functioning, altered their perception of energy level, and affected their emotional and mental well-being.

HISTORY AND PHYSICAL EXAMINATION

The child with allergic rhinitis will typically present with a history of sneezing, runny nose, and itchy eyes. With further questioning, the provider may also uncover indications of lethargy, headache, and loss of productivity in school, hobbies, and sports. The clinician should also inquire about any food sensitivities, because these may complicate the evaluation and treatment of the sensitive patient.

Typical physical findings in allergic rhinitis include the following:

Pale boggy edematous nasal mucous membranes with hyperplasia of turbinates
Constant rubbing of the nose (the allergic salute)
A faint crease over the bridge of the nose (allergic crease)
Allergic shiners (dark circles under eyes)
Associated signs of asthma, allergic rhinitis, sinusitis, or atopic dermatitis

DIAGNOSTIC CRITERIA

The common causes for rhinitis in children are allergies and infections, most of which are viral. Allergic rhinitis is further classified as either seasonal allergic rhinitis (SAR) or perennial allergic rhinitis (PAR). A detailed classification of rhinitis is shown in Display 54-1.

Most patients will have rhinorrhoea, consisting of profuse clear, watery nasal discharge. Itchy nose is frequently present. Multiple fits of sneezing that are explosive in character are typical of allergic rhinitis. Allergic rhinitis seldom occurs alone and is often associated with sinusitis, asthma, and atopic dermatitis. These can present as headaches, sinus congestion, coughing, wheezing, and itchy skin with rashes. Nasal obstruction is frequently seen in allergic rhinitis (especially PAR) and can also result from sinusitis, nasal polyps, nasal septal deviation, tumors, and rarely, granulomatous disorders, such as Wegner’s granulomatosis (Nathan, Meltzer, Selner, & Storms, 1997). Foreign bodies may also lead to nasal obstruction. The complications of allergic rhinitis can include the following:

Sinusitis
Otitis media
Nasal polyps
Asthma
Malocclusion
Deviations in facial growth

DIAGNOSTIC STUDIES

In most children and young adults, the clinical presentation as just described along with physical findings is sufficient to establish the diagnosis of allergic rhinitis. Allergic rhinitis is associated with an increased number of eosinophils in the nasal mucosa. A nasal smear will reveal a high number of eosinophils. Serum IgE will also be elevated. Laboratory tests are rarely necessary because the history almost always clinches the diagnosis.

If the suspicion of allergies playing a role is high, then a limited number of skin tests can be performed by the allergist to pin down those precise allergens responsible for inflammation. This information may help the provider make specific recommendations for environmental control. Current recommendations of the American Academy of Allergy, Asthma, and Clinical Immunology state that skin tests are preferred to radioallergosorbent tests for allergy testing because skin testing has higher sensitivity, is lower in cost, and provides almost immediate results. However, the yield from skin tests is low in children younger than 3 years. Testing will often be negative in this age group.

MANAGEMENT

Referral Point

Allergic rhinitis can be associated with considerable morbidity and a decrease in quality of life. Allergic rhinitis is also often associated with asthma. The provider may find that an allergy consultation may be helpful. Such consultation is also warranted in situations in which the diagnosis of allergic rhinitis is in doubt. Environmental control measures will be cost-effective only in patients with rhinitis for which the primary etiology is allergy. The indications for referral to an allergist are summarized in Display 54-2. Information that the provider should receive back from the allergist is also listed.

DISPLAY 54–2 • Indications for Referral to an Allergist

The primary care provider should refer the patient to an allergist:

When the diagnosis of allergic rhinitis is in doubt
When the condition or its treatment is interfering with the patient’s performance or causing significant loss at school or work
When the patient’s quality of life is significantly affected
When there are complications of rhinitis, such as sinusitis, otitis, hearing loss, asthma, or bronchitis
When the patient requires systemic corticosteroids to control the disease

The allergist consultant should give to the referring provider:

Identification of specific allergens or other triggers for the patient’s condition and education in ways to avoid these triggers
Clarification of allergic or other etiologic basis for the patient’s condition
Assistance in developing an effective treatment plan, including allergy avoidance, pharmacotherapy, and, if necessary, immunotherapy
Provision for specialized services, such as preparation of extracts and provision for immunotherapy

Adapted with permission from Joint Commission on Practice Parameters, Practice Parameter on Cooperative Asthma Management. Journal of Allergy and Clinical Immunology. Presented by Michael Kaliner at AAAAI meeting in New Orleans, March 1996.

Environmental Control

Environmental control forms the basis of all allergy management. These measures are effective, relatively inexpensive, and most assuredly free of any side effects. The measures should be adopted in all patients proven to be allergic by history and skin tests and in young children for whom suspicion of allergy is high but skin testing is deferred because of age, such as toddlers and infants.

Pollens

Pollens are important allergens for seasonal allergic rhinitis. Pollen grains can travel long distances on air currents. The provider should advise parents that there are several strategies that they can use to help their child manage their allergies. Clinical instructions should advise parents to do the following:

Monitor pollen counts.
Keep their child indoors if pollen counts are high or at least limit outdoor trips to rural areas. Rural residents who have seasonal allergies need to be vigilant about their exposure to pollens from nearby woods and fields. Avoid outdoor activities in the morning, because pollen counts are highest early in the day.
Keep windows closed and run air conditioners when indoors during the warm weather months.
Keep windows rolled up in cars.
Avoid lawn mowing and leaf raking. The patient should use a mask if exposure to these activities is absolutely necessary.
Have the child wear wraparound sunglasses or goggles, if possible, when outdoors.

Dust Mites

The most important component of house dust to which patients may become allergic is the dust mite. These microscopic arachnids can cause allergic rhinitis and asthma and may contribute to the pathogenesis of atopic dermatitis. Dust mites live primarily in mattresses, pillows, blankets, carpets, curtains, and upholstered furniture. Their primary food is shed human epithelial cells. Fecal pellets passed by these mites are the main source of dust mite allergen. The clinician should instruct parents that the following steps should be taken to reduce dust mite allergen levels:

Use allergy-proof casings on all mattresses and pillows.
Note that synthetic pillows may not be the best option for allergies, because recent research indicates that levels of dust mite and pet allergens can be found on synthetic pillow surfaces at an eight-fold higher rate than on feather pillows. This finding suggests that the pillow’s surface is more important than what is inside the pillow, in part because the material covering synthetic pillows generally is not as tightly woven as the material covering feather pillows. Feather pillows are covered with tightly woven material to prevent feathers from pushing through to the surface. It is suggested that allergen-proofed or tightly woven pillow encasements be used for patients with dust mite and pet allergies, atopic dermatitis, or asthma (Custovic, Woodock, Craven, et al., 1999; Custovic, Hallan, Woodcock, et. al., 2000).
Wash sheets and pillow slips every 7 days in laundry soap and hot water (130°F). Every 7 to 14 days, wash everything else on the bed (eg, comforters, blankets, and pillows) in laundry soap and hot water (130°F).
Comforters that cannot be washed should be covered in an allergy-proof casing and dry-cleaned (a process that kills mites). Because of the trouble and expense of dry cleaning every 7 to 14 days, parents may opt to switch from non–machine-washable to machine-washable bedding. Mason and colleagues report that hot tumble drying also can effectively kill mites (1999).
Wash the child’s security blanket and stuffed toys as frequently as bedding.
If possible, treat carpets every 4 to 6 months with a product such as Acarosan. This compound works to reduce the number of dust mites, leading to a decrease in dust mite allergen levels.
Remove all carpeting on concrete floors. Such floors tend to trap moisture and promote mite and mold growth. After carpet removal, the concrete needs to be covered with a vapor barrier and washable floor covering, such as vinyl or linoleum.
Dust mites thrive in high humidity. The provider should instruct parents to maintain their home’s indoor humidity at less than 50%. They need to monitor the humidity, using a dehumidifier if necessary.

• Clinical Pearl

Encourage parents to invest in duplicates—at least for the security blanket and the sleep-time stuffed toy. As any parent who has done so knows, frequent hot water washing of much-loved (and, hence, fabric-challenged) items leads to their rapid demise. A little extra expense up-front can save a lot of heartache later. These items should be stored in plastic bags or in the freezer when not in use.

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