ENT · Upper Respiratory Disorders
The facts most likely to be tested
Allergic rhinitis is a Type I hypersensitivity reaction mediated by IgE-dependent release of inflammatory mediators from mast cells.
Physical examination classically reveals pale, boggy, or bluish turbinates and a cobblestoning appearance of the posterior pharynx.
Patients often present with the allergic salute, a transverse nasal crease caused by repetitive upward rubbing of the nose.
The most effective first-line pharmacotherapy for moderate-to-severe symptoms is an intranasal corticosteroid.
Allergic rhinitis is frequently associated with the atopic triad, which includes asthma and atopic dermatitis.
Nasal smears in allergic rhinitis patients typically demonstrate a high concentration of eosinophils.
Oral second-generation antihistamines (e.g., cetirizine, loratadine) are preferred over first-generation agents due to their lack of sedating anticholinergic effects.
Vignette unlocked
A 24-year-old male presents with persistent sneezing, clear rhinorrhea, and itchy, watery eyes that worsen during the spring. He reports a history of childhood eczema and occasional wheezing. On physical exam, he has a transverse nasal crease and his nasal mucosa appears pale and boggy. The posterior pharynx shows cobblestoning of the lymphoid tissue. He has no fever or purulent discharge.
What is the most appropriate initial pharmacologic therapy for this patient's condition?
Intranasal corticosteroid
The patient's presentation of the atopic triad and classic physical exam findings (pale/boggy turbinates) confirms allergic rhinitis, for which intranasal corticosteroids are the most effective first-line treatment.
Full handout
High yield triage
Etiology / Epidemiology
IgE-mediated hypersensitivity to airborne allergens. Atopy (asthma, eczema, rhinitis) is the primary risk factor.
Clinical Manifestations
Sneezing, nasal congestion, and allergic shiners. Pale, boggy turbinates are pathognomonic.
Diagnosis
Clinical diagnosis. Skin prick testing is the gold standard for identifying specific triggers.
Treatment
Intranasal corticosteroids are the first-line therapy. Avoid prolonged use of topical decongestants.
Prognosis
Chronic condition often associated with nasal polyps and secondary sinusitis.
Full handout
Epidemiology & Etiology
Commonly presents in childhood with a strong genetic predisposition to atopy. Triggers include pollen, dust mites, and animal dander. Symptoms are often seasonal or perennial depending on the specific allergen exposure.
Pertinent Anatomy
The nasal mucosa is highly vascularized and innervated by the autonomic nervous system. Inflammation leads to mucosal edema, which obstructs the nasal valve and impairs sinus drainage.
Pathophysiology
Exposure triggers an IgE-mediated Type I hypersensitivity reaction. Mast cell degranulation releases histamine, leukotrienes, and prostaglandins. This cascade causes immediate vasodilation and subsequent late-phase cellular infiltration.
Clinical Manifestations
Patients present with clear rhinorrhea, sneezing, and nasal pruritus. Physical exam reveals allergic shiners (infraorbital edema) and a nasal crease from chronic rubbing. Red flags include unilateral symptoms or purulent discharge, which suggest structural pathology or infection.
Diagnosis
Diagnosis is primarily clinical based on history and physical exam. Skin prick testing is the gold standard to confirm sensitization. Serum total IgE levels are often elevated but lack sufficient specificity for routine use.
Treatment
Intranasal corticosteroids (e.g., fluticasone) are the most effective monotherapy. Oral antihistamines are useful for intermittent symptoms. Topical decongestants (e.g., oxymetazoline) must be limited to <3 days to prevent rhinitis medicamentosa.
Prognosis
Associated with a 30-50% risk of developing asthma. Chronic inflammation may lead to nasal polyps or recurrent acute rhinosinusitis. Long-term management focuses on allergen avoidance and symptom control.
Differential Diagnosis
Non-allergic rhinitis: lack of pruritus and negative allergy testing
Rhinitis medicamentosa: history of excessive topical decongestant use
Acute viral rhinosinusitis: presence of fever and purulent discharge
Foreign body: unilateral foul-smelling discharge in children
Vasomotor rhinitis: triggered by temperature changes or irritants