What is Allergic Rhinitis?

Allergic Rhinitis is an inflammatory disorder of the nasal mucosa triggered by an IgE-mediated immune response to inhaled environmental allergens.
 

• Seasonal Allergic Rhinitis ("Hay Fever"): Triggered by outdoor airborne allergens that follow specific seasonal pollination cycles:

  • Spring: Tree pollens (e.g., oak, birch, cedar).

  • Summer: Grass pollens (e.g., timothy, Bermuda, orchard grass).

  • Fall/Late Summer: Weed pollens (e.g., ragweed, sagebrush) and outdoor mold spores (e.g., Alternaria, Cladosporium).

• Perennial Allergic Rhinitis: Triggered by year-round indoor allergens, including dust mites (fecal proteins in house dust), pet dander (cats, dogs, rodents), cockroach debris, and indoor molds.

• Episodic Allergic Rhinitis: Occurs when an individual is intermittently exposed to an allergen not normally encountered in their everyday environment (e.g., visiting a home with cats).

Common Symptoms & Signs of Allergic Rhinitis
 

• Classic Cardinal Symptoms:

  • Bilateral nasal pruritus (itching of the nose, palate, or throat).

  • Paroxysmal sneezing (frequent, repetitive sneezing fits).

  • Clear, watery rhinorrhea (runny nose).

  • Nasal congestion (stuffiness and nasal blockage).

• Associated Physical Findings:

  • Allergic Shiners: Dark, hyperpigmented infrapalpebral discoloration caused by venous stasis secondary to chronic nasal and sinus congestion.

  • Allergic Salute: A transverse nasal crease across the lower third of the bridge of the nose caused by repeatedly pushing the nose upward and backward with the hand.

  • Dennie-Morgan Lines: Transient folds or creases beneath the lower eyelids, reflecting chronic eyelid edema.

  • Nasal Mucosa Appearance: Typically pale, boggy, edematous, and bluish-gray, bathed in clear or mucoid secretions (distinguishing it from the bright erythematous mucosa seen in acute viral rhinitis).

  • Cobblestoning: Granular lymphoid hyperplasia along the posterior pharyngeal wall from post-nasal drip.

Common Causes
 

• Seasonal Allergic Rhinitis ("Hay Fever"): Triggered by outdoor airborne allergens that follow specific seasonal pollination cycles:

  • Spring: Tree pollens (e.g., oak, birch, cedar).

  • Summer: Grass pollens (e.g., timothy, Bermuda, orchard grass).

  • Fall/Late Summer: Weed pollens (e.g., ragweed, sagebrush) and outdoor mold spores (e.g., Alternaria, Cladosporium).

• Perennial Allergic Rhinitis: Triggered by year-round indoor allergens, including dust mites (fecal proteins in house dust), pet dander (cats, dogs, rodents), cockroach debris, and indoor molds.

• Episodic Allergic Rhinitis: Occurs when an individual is intermittently exposed to an allergen not normally encountered in their everyday environment (e.g., visiting a home with cats).

Diagnostics​
 

• Clinical History: Evaluating symptom timing (seasonal vs. perennial), environmental triggers, family history of atopy, and treatment response.

• Physical Examination: Assessing nasal turbinates, pharynx, tympanic membranes, and classic dermatologic signs.

• Allergy Testing (Confirming Specific Sensitizations):

  • Skin Prick Testing (SPT): The gold standard for rapid identification of specific IgE-mediated sensitivities.

  • Serum Specific IgE Blood Tests (RAST/ImmunoCAP): Used when skin testing is contraindicated (e.g., severe dermatographism, extensive eczema, or inability to safely discontinue antihistamines).

Management 
 

Environmental Control & Avoidance

• Minimizing exposure to identified triggers (e.g., using HEPA air filters, washing bedding in hot water for dust mites, keeping windows closed during high pollen counts, and showering after outdoor exposure).

Pharmacotherapy

• Intranasal Corticosteroids (INCS): First-line and most effective daily therapy. Reduce overall mucosal inflammation, sneezing, itching, and congestion (e.g., fluticasone, mometasone).

• Oral Second-Generation Antihistamines: Non-sedating options that block histamine receptors to control sneezing, itching, and rhinorrhea (e.g., cetirizine, loratadine, fexofenadine). (First-generation agents like diphenhydramine are avoided due to significant sedation and anticholinergic side effects).

• Intranasal Antihistamines: Provide rapid-onset relief for acute symptoms (e.g., azelastine).

• Leukotriene Receptor Antagonists: Montelukast, particularly useful in patients with co-existing asthma.

• Decongestants: Short-term use of oral pseudoephedrine or topical oxymetazoline sprays (limited to $\le$ 3–5 days to prevent rhinitis medicamentosa, or rebound congestion).

Immunotherapy

• Subcutaneous Immunotherapy (SCIT): Traditional allergy shots administered in a clinical setting to gradually induce immune tolerance over 3 to 5 years.

• Sublingual Immunotherapy (SLIT): Daily dissolvable tablets or drops taken at home for specific pollens or dust mites, offering a safe, non-invasive alternative to injections.

​