Rhinitis, Allergic
BASICS
- Definition: IgE-mediated inflammation of the nasal mucosa after exposure to allergens (e.g., pollen, dust, dander).
- Types: Classified as seasonal (outdoor allergens, e.g., pollens) or perennial (indoor allergens, e.g., dust mites, animal dander). Occupational and nonallergic (e.g., vasomotor) rhinitis exist.
- Symptoms: Sneezing, congestion, rhinorrhea, nasal/ocular/pruritus, postnasal drip.
- Pathophysiology: Immediate phase (sneezing, rhinorrhea), late phase (congestion, hyperreactivity).
EPIDEMIOLOGY
- Age of Onset: Usually 8–11 years; rarely <6 months; 80% have onset by age 20.
- Prevalence: 10–25% of US adults, 9–42% of children.
- Mixed Rhinitis: Most patients have both allergic and nonallergic components.
ETIOLOGY & PATHOPHYSIOLOGY
- Mediators: Aeroallergen-driven, with cytokines and inflammatory cells.
- Common Allergens:
- Perennial: House dust mites, molds, animal dander, cockroach.
- Seasonal: Pollens (tree, grass, weed), outdoor molds.
- Occupational: Latex, flour, chemicals, animals.
RISK FACTORS
- Family history of atopy (risk ↑ if both parents affected)
- Higher socioeconomic status, male sex
- Exposure to tobacco smoke, pollutants, pets, cockroaches
- Early introduction of solid foods (uncertain risk)
PREVENTION
- Primary: No strong evidence for maternal diet/allergen avoidance.
- Exclusive breastfeeding to 6 months may lower risk.
- First-line: Environmental control/avoidance of allergens.
- Air conditioning, HEPA filters, closing windows/doors during pollen season, dehumidifiers.
ASSOCIATED CONDITIONS
- Asthma, atopic dermatitis, allergic conjunctivitis, food allergy
DIAGNOSIS
- Clinical Diagnosis: Based on history (congestion, sneezing, pruritus, triggers) and physical findings.
- Physical Exam: Allergic shiners, transverse nasal crease, pale/boggy mucosa, clear rhinorrhea, postnasal drip, oropharyngeal lymphoid hypertrophy.
- Pediatric: Chronic obstruction can cause facial/dental changes, sleep disorders.
- Pregnancy: Rhinitis often worsens in 2nd trimester.
Differential Diagnosis
- Infectious rhinitis, sinusitis, rhinitis medicamentosa, vasomotor rhinitis, hormonal rhinitis, NARES, gustatory rhinitis, nasal polyps/tumor, adenoidal hypertrophy, septal deviation.
Diagnostic Tests
- Not routinely needed.
- Allergen skin testing or RAST if considering immunotherapy or unclear diagnosis.
- CBC (eosinophilia), serum IgE, nasal smear (eosinophils).
- Antihistamines suppress skin test reactivity—stop 7 days before testing.
TREATMENT
Three Main Approaches
- Allergen Avoidance
- Limit exposure (indoor allergens, pollen, workplace triggers)
- Medication
- First-Line:
- Mild/Moderate: 2nd-generation nonsedating antihistamines (cetirizine, fexofenadine, loratadine, levocetirizine)
- Moderate/Severe: Intranasal corticosteroids (beclomethasone, budesonide, fluticasone, mometasone, triamcinolone)
- Use after showering, avoid septum, daily use more effective
- Intranasal antihistamine or steroid sprays also effective
- Second-Line:
- Nasal antihistamines (azelastine, olopatadine)
- Intranasal anticholinergics (ipratropium)
- Leukotriene antagonists (montelukast), esp. with asthma
- Mast-cell stabilizers (cromolyn): optimal effect after 2–4 weeks
- 3rd-gen antihistamines, decongestants (phenylephrine, pseudoephedrine, oxymetazoline ≤3 days)
- Nasal saline sprays/irrigation
- Adjuncts:
- Systemic steroids for urgent, short-term use only
- Biologics (omalizumab, dupilumab) for severe asthma/rhinitis
- Immunotherapy
- Subcutaneous injection of specific allergens (desensitization)
- Consider if refractory to maximal medical management or with comorbid asthma
Additional
- Nasal saline irrigation as sole or adjunctive treatment (daily or bid)
- Start intranasal steroids with 2 sprays/nostril for 2 weeks, then decrease to 1 spray daily
- "5 days on, 2 days off" steroid spray to minimize side effects
ISSUES FOR REFERRAL
- Consider allergist referral for immunotherapy or complex/refractory cases
ONGOING CARE
- Diet: Pollen-sensitive individuals may have oral allergy syndrome with certain fruits/veggies.
- Education: Environmental control, medication adherence.
PROGNOSIS
- Aim: acceptable control of symptoms, reduction of risk for sinusitis, asthma.
- Treatment improves quality of life and decreases complications.
COMPLICATIONS
- Sinusitis, otitis media, epistaxis, lymphoid hyperplasia, airway hyperreactivity, asthma, sleep/facial changes (mouth breathing)
ICD-10 CODES
- J30.89: Other allergic rhinitis
- J30.81: Allergic rhinitis due to animal hair/dander
- J30.2: Other seasonal allergic rhinitis
CLINICAL PEARLS
- Nasal saline irrigation (6–8 oz) before corticosteroids may enhance efficacy.
- 2nd-generation antihistamines and intranasal corticosteroids are first-line.
- Avoid decongestant sprays >3 days (risk of rebound rhinitis).