Medical History
Vasomotor rhinitis is defined as nasal symptoms occurring in response to nonspecific, nonallergic irritants. Common triggers of vasomotor rhinitis are strong odors, respiratory irritants such as dust or smoke, changes in temperature, changes in body position, and ingestants such as spicy food or alcohol. This is considered a nonallergic rhinitis.
• Vasomotor rhinitis is defined as nasal symptoms in response to nonspecific stimuli.
Historical factors favoring a diagnosis of allergic rhinitis include a history of nasal symptoms that have a recurrent seasonal pattern (e.g., every August and September) or symptoms provoked by being near animals. Factors favoring vasomotor rhinitis include symptoms provoked by strong odors and changes in humidity and temperature.
Chapter 2 Allergy 17
Table 2-7 Goals of Asthma Management No asthma symptoms
No asthma attacks Normal activity level Normal lung function
Use of safest and least amount of medication necessary Establish therapeutic relationship between patient and provider
Table 2-8 Diagnostic Features of Allergic Bronchopulmonary Aspergillosis
Clinical asthma
Bronchiectasis (usually proximal) Increased total serum IgE
IgE antibody to Aspergillus (by skin test or in vitro assay) Precipitins or IgG antibody to Aspergillus
Radiographic infiltrates (often upper lobes) Peripheral blood eosinophilia
Symptoms of asthma
Previous diagnosis of
asthma?
No
Yes
No Acute asthma?
Management of acute asthma • β-Agonists
• Corticosteroids • Action plan
• Follow-up for chronic management Establish
diagnosis of asthma
Yes
Interval evaluation • History and physical
• Assess asthma triggers/allergens • Measure pulmonary function – Spirometry
– PEFR
• Consider consultation and/or allergy testing
Assess asthma severity
Step care of pharmacologic treatment
• Mild intermittent • Mild persistent • Moderate persistent • Severe persistent
Asthma education
• Basic facts about asthma • Inhaler technique
• Written action plan, including home PEFR
• Environmental control measures • Emphasize need for regular follow-up visits
Schedule regular follow-up visits
Fig. 2-1.Diagnosis and management of asthma. PEFR, peak expiratory flow rate.
Chapter 2 Allergy 19
Assess severity of asthma exacerbation Patient in ED with acute exacerbation of asthma
1
Hospitalize patient
15
• Out of guideline
• Provide ventilatory support as needed
• Interval assessment within 20 minutes
• PE including vitals, auscultation
• Symptoms
• FEV1 or PEF
• O2 saturation
• Other tests as indicated
• See Annotation #2
• Mild to moderate symptoms Patient demonstrates
• Interval assessment within 20 minutes
• PE including vitals, auscultation
• FEV1 or PEF
• O2 saturation
• Other tests as indicated
• See Annotation #2
Repeat assessment of response to treatment
13
• FEV1 or PEF <50%
• O2 saturation <90%
• Moderate to severe symptoms Patient demonstrates poor
• Continuous or intermittent nebulization with inhaled β-agonist and cholinergic by nebulization
• Initiate corticosteroids, oral or IV
• Consider bi-level PAP or other therapy
• Consider hospitalization Treatment
12
A
• Medication • Asthma action plan
• Asthma education • Follow-up
10
Discharge home
A
Fig. 2-2. Management of acute asthma in adults. A, annotation; ED, emergency department; FEV1, forced expiratory volume in 1 second; IV, intravenous; MDI, metered-dose inhaler; PAP, positive airway pressure; PE, physical examination; PEF, peak expiratory flow (rate). (From ICSI Health Care Guideline: Emergency and Inpatient Management of Asthma. 2nd ed. Institute for Clinical Systems Improvement, Bloomington, Minn., March 2006. Used with permission.)
• Allergic rhinitis has a recurrent seasonal pattern and may be provoked by being near animals.
• Triggers of vasomotor rhinitis include strong odors and changes in humidity and temperature.
Factors common to allergic rhinitis and vasomotor rhinitis (thus, without differential diagnostic value) include perennial symptoms, intolerance of cigarette smoke, and history of “dust” sensitivity.
Factors that suggest fixed nasal obstruction (which should prompt physicians to consider other diagnoses) include unilateral nasal obstruction, unilateral facial pain, unilateral nasal purulence, nasal voice but no nasal symptoms, disturbances of olfaction without any nasal symptoms, and unilateral nasal bleeding (Table 2-9).
• Perennial symptoms, intolerance of cigarette smoke, and history of “dust” sensitivity are common to allergic and vasomotor rhinitis.
• House dust mite sensitivity is a common cause of perennial allergic rhinitis.
Allergy Skin Tests in Allergic Rhinitis
The interpretation of allergy skin test results must be tailored to the unique features of each patient.
1. For patients with perennial symptoms and negative results on allergy skin tests, the diagnosis is vasomotor rhinitis.
2. For patients with seasonal symptoms and appropriately pos-itive allergy skin tests, the diagnosis is seasonal allergic rhinitis.
3. For patients with perennial symptoms, allergy skin tests positive for house dust mite suggest house dust mite allergic rhinitis. In this case, dust mite allergen avoidance should be recommended. Patients should encase their bedding with allergy-proof encasements, remove carpeting from the bedroom, and keep the relative humidity in the house at 40% to 50% or less.
Corticosteroid Therapy for Rhinitis
The need for systemic corticosteroid treatment for rhinitis is limited.
Occasionally, patients with severe symptoms of hay fever may benefit greatly from a short course of prednisone (10 mg four times daily by mouth for 5 days). This may induce sufficient improvement so that topical corticosteroids can penetrate the nose and satisfactory levels of antihistamine can be established in the blood. Severe nasal polyposis may warrant a longer course of oral corticosteroids. Sometimes, recur-rence of nasal polyps can be prevented by continued use of topical corticosteroids. Polypectomy may be required if nasal polyps do not respond to treatment with systemic and intranasal corticosteroids.
• Treatment of nasal polyposis can include oral prednisone, followed by topical corticosteroids.
In contrast to systemic corticosteroid therapy, topical corticosteroid agents for the nose are easy to use and have few adverse systemic effects. Intranasal corticosteroids may decrease growth velocity in children.
• Intranasal corticosteroids may decrease growth velocity in children.
Long-term treatment with decongestant nasal sprays may have
“addictive” potential (a vicious cycle of rebound congestion called
“rhinitis medicamentosa” caused by topical vasoconstrictors). In contrast, inhaled corticosteroid does not induce dependence.
• Unlike decongestant nasal sprays, intranasal corticosteroid does not induce tachyphylaxis and rebound congestion.
A substantial number of patients with vasomotor rhinitis also have a good response to intranasal (topical aerosol) corticosteroid therapy, especially if they have the nasal eosinophilia or nasal polyposis form of vasomotor rhinitis.
Fig. 2-3.Chest radiograph in allergic bronchopulmonary aspergillosis shows cylindrical infiltrates involving the upper lobes.
Table 2-9 Differential Diagnosis of Chronic Rhinitis Allergic rhinitis
Vasomotor rhinitis Rhinitis medicamentosa Sinusitis
Nasal polyposis Nasal septal deviation Foreign body Tumor
• Many patients with vasomotor rhinitis have a good response to topical aerosol corticosteroid therapy.
If a patient with hay fever does not receive adequate relief with topical corticosteroid plus antihistamine therapy, it may indicate the need for systemic corticosteroid treatment and the initiation of immunotherapy.
• If pharmacologic management fails, allergy immunotherapy should be considered for patients with allergic rhinitis.
An unusual side effect of intranasal corticosteroids is nasal septal per-foration. Dry powder spray cannisters deliver a powerful jet of par-ticulates, and a few patients have misdirected the jet to the nasal septum.
• Rarely, topical corticosteroid nasal sprays cause perforation of the nasal septum.
Antihistamines and Decongestants
Antihistamines antagonize the interaction of histamine with its receptors. Histamine may be more causative than other mast cell mediators of nasal itch and sneezing. These are symptoms most often responsive to antihistamine therapy.
Pseudoephedrine is the most common agent in nonprescription drugs for treating cold symptoms and rhinitis and usually is the active agent in widely used proprietary prescription agents.
Phenylpropanolamine has been removed from the market because of its association with hemorrhagic stroke in women. Several prescription and nonprescription combination agents combine an antihistamine and decongestant. Decongestant preparations are often the only therapeutic option for patients with vasomotor rhinitis unresponsive to topical glucocorticoids.
• Pseudoephedrine is the most common decongestant in nonpre-scription preparations.
Middle-aged and older men may have urinary retention caused by antihistamines (principally the older drugs that have anticholinergic effects) and decongestants. Although there has been concern for years that decongestants may exacerbate hypertension because they are α-adrenergic agonists, no clinically significant hypertensive response has been seen in patients with hypertension that is controlled medically.
• Antihistamines and decongestants may cause urinary retention in men.
• The elderly are more sensitive to the anticholinergic effects of antihistamines.
Immunotherapy for Allergic Rhinitis
Until topical nasal glucocorticoid sprays were introduced, allergen immunotherapy was considered first-line therapy for allergic rhinitis when the relevant allergen was seasonal pollen of grass, trees, or weeds. Immunotherapy became second-line therapy after topical corticosteroids were introduced because immunotherapy 1) requires more time commitment during the build-up phase and 2) carries a
small risk of anaphylaxis to the immunotherapy injection itself.
However, immunotherapy for allergic rhinitis can be appropriate first-line therapy in selected patients and is highly effective.
Immunotherapy is usually reserved for patients who have no satisfactory relief from intranasal corticosteroids or who cannot tolerate antihistamines. Controlled trials have shown a benefit for pollen, dust mite, and cat allergies and a variable benefit for mold allergy.
Immunotherapy is not used for food allergy or nonallergic rhinitis.
The practice is less uniform with respect to mold allergens, with endorsement divided in the subspecialty.
• Immunotherapy usually is reserved for patients who receive no relief from intranasal glucocorticoids or who cannot tolerate antihistamines.
• Controlled trials have shown that immunotherapy is effective for allergic rhinitis.
• Anaphylaxis is a risk of immunotherapy.
• Immunotherapy for allergic rhinitis can be first-line therapy in selected patients.
Environmental Modification House Dust Mites
House dust mites are so small that they cannot maintain their own internal water unless the ambient humidity is high. They eat all kinds of organic matter but seem to favor mold and epidermal scale shed by humans. They occur in all human habitations, although the population size varies with local conditions. The only geographic areas free of house dust mites are at high elevations with extreme dryness.
• House dust mites require high humidity to survive.
• They are found in nearly all human habitations.
Areas in the home harboring the most substantial mite populations are bedding and fabric-upholstered furniture (heavily used) and any area where carpeting is on concrete (when concrete is in contact with grade). Although carpeting is often cited as an important mite-related problem, carpet on wooden floors in a dry, well-ventilated house usually harbors only a small number of dust mites. Aerosol dispersion of allergen from this source is not great compared with that from bedding and furniture. To prevent egress of allergen when the mattress and pillows are compressed by occupancy of the bed, encase the bedding (and sometimes, when practical, furniture cushions) in plastic dust-proof encasements. To some degree, this also prevents infusion of water vapor into the bedding matrix. These two factors combine to markedly decrease the amount of airborne allergen. In contrast, recently marketed acaricides that kill mites or denature their protein allergens have not proved useful in the home. Measures for controlling dust mites are listed in Table 2-10.
• Dust mite is an important respiratory allergen.
• The most substantial mite populations are in bedding and fabric-upholstered furniture.
• Plastic encasements prevent egress of allergen.
Chapter 2 Allergy 21
• Chemical sprays (acaricides) capable of either killing mites or denaturing the protein allergens are not substantially helpful when applied in the home.
Pollen
Air conditioning, which enables the warm-season home to remain tightly closed, is the principal defense against pollinosis. Most masks purchased at local pharmacies cannot exclude pollen particles and are not worth the expense. Some masks can protect the wearer from allergen exposure. These include industrial-quality respirators designed specifically to pass rigorous testing by the Occupational Safety and Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) and be certified as capable of excluding a wide spectrum of particulates, including pollen and mold. These masks allow persons to mow the lawn and do yard work, which would be intolerable otherwise because of exposure to pollen allergen.
• Only industrial-quality masks are capable of excluding pollen particles.
Animal Dander
No measure can compare with getting the animal completely out of the house. No air filtration scheme that is feasible for average homeowners to install can eliminate allergen from an actively elab-orating animal. If complete removal is not tenable, some partial measure must be considered.
If the house is heated or cooled by a forced-air system with ductwork, confining the pet to a single room in the house is only partially effective in reducing overall exposure, because air from every room is collected through the air-return ductwork and redistributed through a central plenum. If air-return ducts are sealed in the room where the animal is kept and air can escape from the room only by infiltration, exposure may be reduced. The room selected for this measure should be as far as possible from the bedroom of the person with the allergy. Naturally, the person should avoid close contact with the animal and should consider using a mask if handling the animal or entering the room where the animal is kept is necessary. Most animal danders have little or nothing to do with animal hair, so shedding status is irrelevant. Bathing cats about once every other week may reduce the allergen load in the environment.
• Complete avoidance is the only entirely effective way to manage allergy to household pets.
Sinusitis
Sinusitis is closely associated with edematous obstruction of the sinus ostia (the osteomeatal complex). Poor drainage of the sinus cavities predisposes to infection, particularly by microorganisms that thrive in low oxygen environments (e.g., anaerobes). In adults, Streptococcus pneumoniae, Haemophilus influenzae, anaerobes, and viruses are common pathogens. In addition, Branhamella catarrhalis is an important pathogen in children.
Important clinical features of acute sinusitis are purulent nasal discharge, tooth pain, cough, and poor response to decongestants.
Findings on paranasal sinus transillumination may be abnormal.
• Purulent nasal discharge, tooth pain, and abnormal findings on transillumination are important clinical features of sinusitis.
Physicians should be aware of the complications of sinusitis, which can be life-threatening (Table 2-11). Mucormycosis can cause recur-rent or persistent sinusitis refractory to antibiotics. Allergic fungal sinusitis is characterized by persistent sinusitis, eosinophilia, increased total IgE, antifungal (usually Aspergillus) IgE antibodies, and fungal colonization of the sinuses. Wegener granulomatosis, ciliary dyski-nesia, and hypogammaglobulinemia are medical conditions that can cause refractory sinusitis (Table 2-12).
Untreated sinusitis may lead to osteomyelitis, orbital and peri-orbital cellulitis, meningitis, and brain abscess. Cavernous sinus thrombosis, an especially serious complication, can lead to retrobulbar pain, extraocular muscle paralysis, and blindness.
Persistent, refractory, and complicated sinusitis should be evaluated by a specialist. Sinus computed tomography (CT) is the preferred imaging study for these patients (Fig. 2-4).
Amoxicillin, 500 mg three times daily, or trimethoprim-sul-famethoxazole (one double-strength capsule twice daily) for 10 to 14 days is the treatment of choice for uncomplicated maxillary sinusitis.
The sensitivity of plain radiography of the sinuses is not as good as that of CT (using the coronal sectioning technique). Good-quality coronal CT scans show greater detail about sinus mucosal surfaces, but CT usually is not necessary in acute uncomplicated sinusitis. CT is indicated, though, for patients being considered for a sinus operation and for those in whom standard treatment for sinusitis fails. However, patients with extensive dental restorations Table 2-10 Dust Mite Control
Encase bedding and pillows in airtight encasements Remove carpeting in bedroom
Remove upholstered furniture from bedroom Remove all carpeting laid on concrete Discontinue use of humidifier Wash bedding in hot water Run dehumidifier
Table 2-11 Complications of Sinusitis Osteomyelitis
that contain metal may generate too much artifact for CT to be useful. For these patients, magnetic resonance imaging techniques are indicated.
• Sinus imaging is indicated for recurrent sinusitis.
• Sinus CT is preferred to sinus radiography for complicated sinusitis.