About
- Personal or family history of atopic dermatitis, allergic rhinitis, or asthma
Aetiology
- Personal or family history of atopic dermatitis, allergic rhinitis, or asthma
Clinical
- Seasonal symptoms, especially while outdoors during pollen season, usually due to plant pollens or molds
- Perennial symptoms, often worse upon arising, usually due to dust mites or other insect allergens, molds, animal allergens, or occupational exposure
- Acute: nasocular itching, tearing, rhinorrhea, repetitive sneezing, nasal blockage
- Chronic
- Postnasal drainage & congestion
- Ocular signs include conjunctival injection, chemosis, allergic shiners
- External nasal crease indicative of nasal itching (allergic salute)
- Nasal exam reveals pale, boggy nasal mucosa w/ clear secretions, enlarged turbinates, narrowed nasal airway
- Chronic mouth breathing may lead to high-arched palate & micrognathia
Investigations
- FBC: peripheral eosinophilia
- Nasal smear reveals metachromatic cells & eosinophils, useful for distinguishing allergic from other forms of rhinitis
- Identify specific IgE antibodies to suspected allergens by skin testing or in vitro (RAST) tests. These are helpful when they corroborate the history of exposure.
Complications
- Sinusitis: common. Treatment: mucolytic agents, decongestants, saline lavage; amoxicillin + clavulanate for 3-wk course for refractory cases
- Asthma: Assess w/ office spirometry & treat w/ inhaled beta-agonist & inhaled or systemic steroids as warranted
- Otitis media: Amoxicillin + clavulanate for 10-day course
- Snoring/sleep disruption/apnea: during pollen season in 10.30% of pts. Treat underlying inflammation; add decongestants
- Nasal polyps: obstructive symptoms. May require polypectomy if unresponsive to prednisone
Management
- Avoidance of known allergens. Stay indoors when pollen counts are highest (usually early AM & windy conditions). Encase mattress & pillow for dust mite allergy. Remove or limit contact w/ pet. Identify & remove sources of mold exposure. Occupation. Some jobs are high risk
- Nonsedating antihistamines: Cetirizine, Fexofenadine, Loratadine
- Pseudoephedrine as needed for nasal congestion
- Intranasal corticosteroids: Budesonide, Fluticasone, Mometasone