Allergic rhinitis is an acute or chronic inflammation of the nasal mucosa caused by a type 1 hypersensitivity reaction to an inhaled allergen (e.g., dust, animal dander, mold spores, plant pollen). It is the most common form of rhinitis and is associated with other allergic conditions such as atopic dermatitis and asthma. Clinical manifestations of allergic rhinitis include nasal congestion, rhinorrhea, sneezing, and postnasal drip. Exacerbation of allergic rhinitis symptoms may occur in certain seasons or with exposure to certain allergens. Allergic rhinitis is typically diagnosed based on clinical features. Allergen testing helps determine the causative allergen and may also be used to confirm the diagnosis if there is clinical uncertainty. Initial management involves allergen and irritant avoidance and pharmacotherapy with intranasal corticosteroids or oral or intranasal antihistamines. Allergen immunotherapy may be considered if initial treatment does not provide adequate symptom relief.
- Etiology: type I hypersensitivity reaction (an IgE-mediated process) 
- Risk factors 
- Recurrent episodes of sneezing, nasal congestion, rhinorrhea, and postnasal drip
- Itchy nose and throat
- Pale, boggy nasal mucosa with hypertrophic turbinates
- Nasal polyps are seen in 25–30% of patients with chronic allergic rhinitis. 
- Cobblestone appearance of the posterior pharyngeal wall
- Allergic shiners: hyperpigmentation and edema of the lower eyelid as a result of venous congestion
- Allergic salute: a habit of wiping the nose with a transverse or upward movement of the hand
- Allergic nasal crease: a transverse hyperpigmented or hypopigmented line that is seen at the junction of the lower third and the middle third of the nasal bridge, which is the natural crease formed when the nose is pushed upwards by the allergic salute
- Chronic allergic rhinitis can predispose the patient to recurrent and/or .
Hypertrophic turbinates are pink or violaceous, hard, sensitive to probing, immobile, and shrink with nasal decongestant therapy. Nasal polyps are pale, soft, mobile, insensitive, and do not decrease in size following therapy with nasal decongestants.
Classification on the basis of a temporal pattern of allergen exposure may help identify the causative antigen. Classification based on the frequency and duration of symptoms is useful for guiding treatment. 
|Clinical classification of allergic rhinitis |
|Temporal pattern of allergen exposure|| |
Episodic allergic rhinitis
|Symptoms occur on exposure to allergens that are not normally a part of the individual's environment.|
Seasonal allergic rhinitis
|Symptoms occur on exposure to allergens that occur during particular seasons.|
Perennial allergic rhinitis
|Symptoms occur on exposure to allergens that are normally a part of the patient's environment.|
Intermittent allergic rhinitis
|Duration of symptoms: < 4 days/week or < 4 weeks/year|
Persistent allergic rhinitis
|Duration of symptoms: > 4 days/week for > 4 weeks/year|
Mild allergic rhinitis
|Symptoms do not interfere with the quality of life.|
|Moderate to severe allergic rhinitis||Symptoms interfere with the quality of life.|
- Obtain a detailed clinical history identifying:
- Order allergen testing:
- Additional diagnostic modalities (e.g., imaging and nasal endoscopy)
- Not routinely required
- Consider in cases of diagnostic uncertainty (e.g., to rule out sinonasal disorders). 
Allergic rhinitis is primarily a clinical diagnosis in patients presenting with characteristic clinical features (i.e., nasal congestion, rhinorrhea, itchy nose, sneezing) that are triggered by seasonal, perennial, or episodic exposure to allergens. 
Allergen testing 
- Indication: preferred over blood tests as they are more sensitive
- Possible contraindications
- Options 
- Presence of contraindications for skin tests
- Patient preference
- Method: immunoassays to identifiy allergen-specific IgE in the serum ()
- Recommend environmental modifications.
- Initiate pharmacotherapy with antihistamines (intranasal or oral) or intranasal corticosteroids.
- Assess response to therapy in 5–7 days.
- If symptoms are under control:
- Step down and stop pharmacotherapy if the trigger is no longer present.
- Or administer treatment on an as-needed basis.
- If symptoms are uncontrolled, consider any of the following :
- If symptoms are under control:
Environmental modifications 
- Advise patients to avoid exposure to putative allergens (e.g., dust, animal dander, mold spores, plant pollen, or latex).
- Examples of environmental modifications include:
Medications for allergic rhinitis can be initiated empirically. The choice of initial pharmacotherapy depends on the severity and and should be tailored to the clinical response (see “Approach” above).
- Episodic allergic rhinitis, intermittent seasonal allergic rhinitis, or perennial allergic rhinitis: : intranasal or oral second-generation antihistamines on an as-needed basis
- Persistent allergic rhinitis
- Select patients: : Consider adding symptom-specific agents (e.g., decongestants, anticholinergics) to intranasal corticosteroid and antihistamine therapy.
Intranasal steroids are considered the most effective maintenance treatment for persistent allergic rhinitis. Potential adverse effects include nosebleeds and, rarely, septal perforation with long-term use. 
|Medications for allergic rhinitis |
|Drug class|| |
|Intranasal corticosteroids|| |
|Decongestants (α1-sympathomimetics)|| |
|Mast cell stabilizers|| |
|Leukotriene receptor antagonists|
Allergen immunotherapy 
- Controlled exposure to gradually increasing doses of the allergen (sublingually or subcutaneously) in order to reduce sensitivity to the allergen 
- Consider in patients with allergen-specific IgE antibodies and any of the following: 
- Generally requires ≥ 3 years of treatment