Description
- presence of more than 1 of nasal congestion, rhinorrhea, sneezing, and itching
- twelfth most common diagnosis in family physician visits
Types
- seasonal allergic rhinitis (SAR, hay fever)
- common aeroallergen triggers in USA include
- grasses (timothy, Bermuda)
- outdoor mold spores
- weeds (ragweed)
- trees (birch, oak, maple, mountain cedar)
- common aeroallergen triggers in USA include
- perennial rhinitis
- common triggers include
- dust mite
- indoor molds
- animal dander
- pollen in some climates
- occupational allergens
- common triggers include
- episodic rhinitis (occasional exposure)
- mixed rhinitis (presence of both AR and non-AR) affects 44% to 87% of patients with AR
Likely risk factors
- family history of atopy
- serum IgE > 100 units/mL < age 6 years
- higher socioeconomic class
- atopy
- air pollution
- maternal AR and intranasal corticosteroid use during pregnancy
Possible risk factors
- smoking
- FLG mutation
Factors not associated with increased risk
- infant vaccinations
- pet ownership < age 2 years
- antibiotic use before age 5
- introduction of solid foods before age 4 months
- recurrent otitis media
Factors associated with reduced risk
- early and long-term exposure to stables and farm milk
Associated conditions
- other atopic disease
- asthma
- atopic dermatitis
- allergic conjunctivitis
- nasal polyps
- sinusitis
- sleep apnea
- atherosclerosis
- oral allergy syndrome
- otitis media with effusion
Causes
- aeroallergens
Pathogenesis
- biphasic IgE type I allergic inflammatory mediator response to aeroallergens
- immediate response (within minutes of exposure, peaks at 15 to 30 minutes)
- release of mediators from mast cells
- preformed (such as histamine, tryptase, chymase, kininogenase, heparin)
- newly formed mediators, such as prostaglandins
- release of mediators from mast cells
- late phase response (starts 4 to 8 hours after exposure, release of cytokines and leukotrienes)
- immediate response (within minutes of exposure, peaks at 15 to 30 minutes)
History
- Chief concern (CC)
- sneezing, rhinorrhea, nasal congestion
- copious rhinorrhea and sneezing within minutes of exposure to allergen
- nasal congestion (later)
- Medication history
- assess response to past medications
- Family history (FH)
- assess family history of
- atopic disorders
- chronic sinus complaints or infections, or recurrent bronchitis
- assess family history of
- Social history (SH)
- occupational exposure
- presence of mold and water damage in home
Physical
- HEENT
- nasal findings
- pale or bluish boggy nasal mucosa (edematous turbinates covered with thin clear secretion)
- nasal airway obstruction
- transverse nasal crease (“allergic crease” due to “allergic salute” of hand pushing nose up)
- throat findings
- postnasal mucous discharge
- tonsillar hypertrophy
- cobblestoning (lymphoid hypertrophy of posterior pharynx)
- mouth breathing (nasal obstruction)
- eye exam may show
- “allergic shiners” (infraorbital venous congestion)
- conjunctival injection and swelling
- tearing
- Dennie lines on eyelids (Dennie-Morgan folds)
- tympanic membrane dullness
- rarely high arched palate, overbite malocclusion (adenoid facies)
- nasal findings
Making the diagnosis
- diagnosis usually based on history and exam
- typical history includes
- nasal symptoms
- seasonal or perennial symptom pattern
- identification of precipitating factors such as exposure to dust, pollen, or animal dander
- identification of coexisting atopic conditions
- physical findings may be slight or absent
- history may elicit enough information to justify presumptive treatment
Causes of nonallergic rhinitis
- vasomotor
- gustatory
- nonallergic rhinitis with eosinophilia
- syndrome (NARES)
- atrophic
- drug-induced
- rhinitis medicamentosa (topical decongestants or cocaine)
- infectious
- hormonal
- pregnancy
Complications
- sinusitis
- conjunctivitis
- sleep apnea/poor sleep
- high arched palate
- dental malocclusion
- school absenteeism
- impaired cognitive functioning
Prognosis
- in most children, may persist >10 years
- in adults mostly chronic with variable severity