II. Epidemiology
- Onset under age 30
- Peak Incidence in childhood and adolescence
- Most common chronic disease in United States
- Affects 15 to 30% in U.S.
- Accounts for two million missed school days
- Accounts for three million missed work days
- Significantly affects quality of life
III. Pathophysiology
- IgE mediated, type I Antibody-Antigen reaction to allergens
- May take 4 years in a given region to be sensitized
- Sequence of events
- T Lymphocytes and B Lymphocytes release IgE Antibody
- Mast Cells in skin and mucosa are activated with second exposure mediated IgE-mediated cross-linking
- Mast Cells and intravascular Basophils degranulate
- Release of Histamine and chemotactic factors, Prostaglandins and Leukotrienes
- Results in mucosal vasodilation and edema, and nasal obstruction
- Late phase reactants release Histamine over 12 hour
IV. Associated Conditions
-
Atopy
- Eczematous Dermatitis
- Allergic Rhinitis
- Asthma
-
Allergic Triad (Samter's Triad)
- Aspirin Allergy
- Nasal Polyps
- Aspirin-Exacerbated Respiratory Disease (AERD) or Asthma
V. History
- Family History
- Other Risk Factors
- Atopy
- History of Nasal Trauma
- Medication use
- NSAIDs
- Antihypertensive Medications
- Oral Contraceptives
VI. Causes: Suspected Environmental Allergens
- Seasonal Allergens (U.S.)
- Tree pollen (early spring)
- Grass pollen (late spring)
- Outdoor Molds (summer and fall)
- Weed pollen (esp. ragweed, late summer to fall)
- Perennial
- Dust mites
- Animal dander
VII. Symptoms
- Specific
- Sneezing
- Rhinorrhea
- Nasal congestion
- Pruritus of the nose, eyes, and throat
- Eye Tearing and Conjunctival discharge
- Chronic Nasal Obstruction
- Mouth Breathing
- Snoring
- Anosmia
- Cough
- Headache
- Decreased Hearing
- Halitosis
-
Generalized due to chronicity of Rhinitis
- Irritability
- Fatigue
- Depression
- Malaise
- Weakness
VIII. Signs
- Vitals
- Rule out Hypertension associated with Antihistamines
- Nose
- Use Nasal speculum with high power illumination
- Examine before and after topical nasal Decongestant
- Mucosa
- Pale blue
- Boggy
- Clear discharge
- Ocular
- Palpebral Conjunctiva pale and swollen
- Bulbar Conjunctiva injected with clear discharge
- Face
- Allergic Shiners
- Bluish purple rings around both eyes
- Results from chronic mid-face venous congestion
- Dennie's Lines
- Skin folds under eyes
- Allergic Salute
- Transverse nasal crease from chronic nose rubbing
- Allergic Shiners
- Mouth
- Ear (Rule out associated Eustachian Tube Dysfunction)
- Dull, immobile Tympanic Membrane
- Conductive Hearing Loss
- Sinus (Rule out Sinusitis)
- Purulent discharge
- Tender
- Impaired transillumination
IX. Labs
- Background
- Allergic Rhinitis may be made on clinical grounds without specific testing
- Consider Allergy Testing when there is inadequate treatment response or diagnosis is unclear
- Allergy Testing is also indicated when instituting allergan specific treatment
-
Skin Testing
- Gold standard
- Test Sensitivity 80 to 90%
-
RadioAllergoSorbent Test (RAST Test)
- Use if unable to skin test contraindicated (e.g. Anaphylaxis, severe dermatologic conditions)
- Test Sensitivity 70 to 75%
- Test Specificity 80 to 100%
- Nasal Smears
- Eosinophils supportive of a diagnosis
-
Complete Blood Count
- Normal White Blood Cell Count
- Increased Eosinophils
- IgE elevated (generally and allergan specific increases)
- IgE Levels are not correlated with clinical severity
X. Differential Diagnosis
- See Rhinitis Causes
- Irritants ( Cigarette Smoke, fumes and chemicals) are typically unrelated to Allergic Rhinitis
XI. Management: General Measures
- Decrease Environmental Allergens
-
Nasal Saline
- Reduces symptoms and overall allergy medication use
- Hermelingmeier (2012) Am J Rhinol Allergy 26(5): e119-25 [PubMed]
-
Non-Sedating Antihistamines
- May be reasonable to use as first-line if taken as needed only occasionally
- If regular use needed, then Intranasal Steroids are preferred
XII. Management: First-Line - Intranasal Steroids
- See Intranasal Steroid
- Effects
- Effectively controls itching, sneezing and discharge
- Moderately controls blockage symptoms
- Small effect on impaired smell
- Onset of action within hours, but maximal effect requires 2-4 weeks of continuous use
- More effective than Antihistamines
- Agents (Pregnancy category C unless otherwise noted)
XIII. Management: First-Line - Antihistamines (non-sedating preferred)
- Effects
- Effectively controls itching and sneezing symptoms
- Moderately controls discharge
-
Non-Sedating Antihistamines (first-line)
- Age 6 months and older
- Cetirizine (Zyrtec, Pregnancy category B)
- Desloratadine (Clarinex, Pregnancy category C, perennial allergies)
- Levocetirizine (Xyzal, Pregnancy category B, perennial allergies)
- Age 2 years and older
- Loratadine (Claritin, Pregnancy category B)
- Desloratadine (Clarinex, Pregnancy category C, seasonal allergies)
- Levocetirizine (Xyzal, Pregnancy category B, seasonal allergies)
- Age 6 years and older
- Fexofenadine (Allegra, Pregnancy category C)
- Age 6 months and older
-
Sedating Antihistamines (for age 6 years and older; Non-Sedating Antihistamines are preferred instead)
- Diphenhydramine (Benadryl, Pregnancy Category B)
- Chlorpheniramine (ChlorTrimeton, Pregnancy Category B)
XIV. Management: Second-line Agents
- Overall symptoms persist
- Intranasal Antihistamines (pregnancy category C)
- Azelastine (Astelin)
- Approved for age >5 years (seasonal allergies) and >6 years (perennial allergies)
- Olopatadine (Patanase)
- Safe at 6 years and older
- Azelastine (Astelin)
- Leukotriene Antagonists (risk of Major Depression and Suicide)
- Montelukast (Singulair)
- Pregnancy Category B
- Approved for age >6 months (perennial allergies) and >2 years (seasonal allergies)
- Montelukast (Singulair)
- Intranasal Cromolyn (marginally effective, Mast Cell Stabilizer)
- Intranasal Antihistamines (pregnancy category C)
-
Rhinorrhea predominates
- See Rhinitis
- Nasal Saline
- Intranasal Ipratropium (Intranasal Atrovent)
- Effectively controls Nasal Discharge
- Ocular symptoms predominate
- Ocular Allergy Preparations (e.g. Patanol)
XV. Management: Refractory management
- Overall symptoms refractory to above measures
- Refer to allergy
- Allergy Testing
- Omalizumab (Xolair, approachs $1000 per dose)
- Anti-Immunoglobulin EAntibody
- Primarily indicated in Asthma, but also improves Allergic Rhinitis nasal symptoms
- Casale (2001) JAMA 286(23): 2956-67 [PubMed]
- Immunotherapy
- Subcutaneous Immunotherapy (standard, broad variety of allergens available)
- Sublingual Immunotherapy (expensive, limited allergens available)
- Severe acute exacerbation
- Generally avoid Systemic Corticosteroids in Allergic Rhinitis (use Inhaled Corticosteroids instead)
- However, some consultants will use short-course systemic steroids in severe cases (but poor evidence)
- Karaki (2013) Auris Nasus Larynx 40(3): 277-81 [PubMed]
- Generally avoid Systemic Corticosteroids in Allergic Rhinitis (use Inhaled Corticosteroids instead)
- Other measures
- Petrolatum
- Applied 4 times daily to inside of nares
- Reduces nasal allergic symptoms
- Schwetz (2004) Arch Otolaryngol Head Neck Surg 130 [PubMed]
- Petrolatum
XVI. Complications
- Insomnia
- Inattention and Irritability
- Missed work and school
- Most common reason in U.S. for missed work
- Lamb (2006) Curr Med Res Opin 22(6): 1203-10 [PubMed]
XVII. References
- Plaut (2005) N Engl J Med 353(18): 1934-44 [PubMed]
- Price (2006) Prim Care Respir J 15(1): 58-70 [PubMed]
- Scadding (2008) Clin Exp Allergy 38(1): 19-42 [PubMed]
- Sur (2010) Am Fam Physician 81(12): 1440--6 [PubMed]
- Sur (2015) Am Fam Physician 92(11): 985-92 [PubMed]
- Wallace (2008) J Allergy Clin Immunol 122(2 suppl): S1-84 [PubMed]
- Weaver-Agostoni (2023) Am Fam Physician 107(5): 466-73 [PubMed]