DIAGNOSIS AND PHYSICAL EXAM FINDINGS
In terms of diagnosis of allergic rhinitis, the history and physical should yield the diagnosis with confirmation by skin prick testing or specific IgE by Immunocap methodology on serum to further identify specific allergens. Skin prick testing is considered to be more sensitive and less expensive than serum testing and has the benefit of the results being immediately available for the patient. Antihistamines, depending on their half-life, should generally be withheld for five to seven days before skin testing to avoid blocking measurement of wheal and flare response due to mast cell histamine release. The likelihood of a systemic reaction on skin prick testing( not intradermal testing) is rare with some estimates as low as one in 10,000. Furthermore, skin prick testing is very accurate at predicting clinical reactivity based on exposure chamber studies and outdoor park studies and is associated with less false positives. Skin testing can provide a“ road map” of what is to come in the future in terms of predicting patient symptoms and can better guide environmental control measures and medical management.
Physical exam findings consistent with allergic rhinitis generally include swollen boggy turbinates with pale mucosa and clear mucous.( 3) Exam findings consistent with infection may include purulent mucous and erythema of the turbinates. Non-allergic rhinitis is usually characterized by an erythematous mucosal surface with clear secretions thought this is not always a reliable predictor. A nasal crease along the top of the nose suggests frequent nasal pruritus and allergic shiners under the eyes suggest underlying nasal congestion. Septal deviation, nasal polyps, nasal spurs and other anatomical abnormalities can also be detected on nasal exam.( 3)
DIFFERENTIAL DIAGNOSIS
It is important to note that not everyone that has congestion, rhinitis, sneezing and postnasal drainage has a positive allergy test. These skin test negative patients can have a non-IgE mediated cause of symptoms known as non-allergic rhinitis or vasomotor rhinitis with or without nasal eosinophilia. In these patients, it is important to inform them that irritants such as cleaning supplies, perfumes, cigarette smoke, air-fresheners and other noxious stimuli can trigger symptoms. Other causes of non-allergic rhinitis include cold air, weather changes and pollution. In addition, congestion may be due to medications, other medical conditions, anatomical abnormalities, or chronic rhinosinusitis with or without polyps. Table III is a classification table of rhinitis and outlines the differential diagnosis of nasal symptomatology.( 2, 3)
As one considers this differential diagnosis, it becomes more apparent that your patient with chronic congestion may have a very complex diagnosis, including sinus disease.( 3) Chronic rhinosinusitis includes symptoms of decreased smell, facial pain or pressure, postnasal drainage, nighttime cough, and nasal congestion of 12-weeks duration. Chronic rhinosinusitis may be associated with or without polyps. These patients often have coexisting asthma and these patients can react to aspirin or other NSAIDS with an occurrence rate as high as 20 percent. Idiosyncratic reactions are non IgE mediated and occur in these patients who previously took an aspirin or NSAID safely and then later had a severe asthmatic
TABLE III. CLASSIFICATION OF RHINITIS AND DIFFERENTIAL DIAGNOSIS
FEATURE
I. Allergic Rhinitis- Positive skin prick test and / or positive specific IgE( Immunocap testing) and nasal provocation
II. Non-Allergic Rhinitis with or without Eosinophilia, Vasomotor, Gustatory. Negative skin prick test and / or negative specific IgE( Immunocap testing)
III. Local Allergic Rhinitis. Negative skin prick test and / or negative specific IgE( Immunocap testing) Positive Nasal provocation, local specific IgE in nasal mucosal Positive nasal allergen challenge
IV. Medication induced rhinitis and other medical conditions. Rhinitis medicamentosa: Topical Nasal Decongestants, ie, oxymetazoline, pseudoephedrine, and phenylephrine Other medications: Oral Contraceptives, Ace-I’ s, PDE-5 inhibitors, alpha receptor antagonists, aspirin, NSAIDS( Samter’ s Triad) Medical conditions: Hypothyroidism, hormonal, pregnancy
V. Anatomical Consideration- Foreign body, septal deviation, other anatomical issues, Haller cell, concha bullosa, enlarged adenoids, nasal polyps, tumor VI. Infectious. Viral( most common) bacterial or fungal infection VII. Chronic rhinosinusitis- Chronic rhinosinusitis without nasal polyps( TH1 mediated), Chronic rhinosinusitis with nasal polyps( TH2 mediated)
reaction to the same previously tolerated medication. Treatment of these patients often includes prednisone and extensive nasal hygiene with nasal saline irrigations and chronic nasal steroids. Newer biologicals indicated for asthma including anti-IgE( omalizumab, lowers IgE) and anti-IL-5( mepolizumab, reslizumab, both lower eosinophils) have shown some benefit in upper nasal airway disease, but thus far are not indicated for isolated chronic sinusitis with nasal polyps.( 14) More recently, studies have shown that anti-IL4, anti-IL13 therapy with dupilumab( currently indicated for adults with atopic dermatitis) may in fact reduce polyps significantly resulting in improved airway flow, and improved sense of smell.( 15) Surgery may be necessary to get control of underlying polyp burden, but polyps frequently reoccur despite surgery.
Editor’ s note: This is a two-part series on allergic rhinitis. Part two will focus on treatment, expectant mothers and immunotherapy with references listed at the conclusion.
F. Tolis Simon, MD holds board certifications in both Allergy & Immunology and Internal Medicine. He is a third generation allergist in Louisville, KY, and has been practicing for 20 years. He is in private practice at Bluegrass Allergy and Asthma in Jeffersontown, KY, and also works part-time at the Family Health Centers, Inc. Dr. Simon is an associate faculty member at both the University of Louisville and the University of Kentucky.
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