Allergic Rhinitis Flashcards
Definition of allergic rhinitis
An IgE-mediated inflammatory disorder of the nose which occurs when the nasal mucosa become exposed and sensitised to allergens
Classification of allergic rhinitis
- Seasonal (symptoms occur at the same time each year in response to a seasonal allergen)
- Perennial (typically due to house sut mites and animal dander)
- Intermittent (less than 4 days a week or less than four consecutive weeks)
- Persistent (more than four days a week and more than four consecutive weeks)
What is the cause of allergic rhinitis
House dust mites (present all year, but numbers peak in spring and autumn), grass, tree and weed pollen, mould and animal dander
What is the prevalence of allergic rhinitis, what is the peak age of onset
- 10% of 6 and 7 year olds, and 15–19% of 13 and 14 year olds, are affected by allergic rhinitis in England
- There is a sharp increase in the lifetime prevalence in males and females during the first two decades of life, with peak lifetime prevalence occurring in the 15–19 years age group. Following this, the lifetime prevalence steadily declined in both sexes
Complications of allergic rhinitis
- Impaired school performance (difficulty concentrating, irritability, sleep disturbance)
- Asthma (commonly co-exist however, allergic rhinitis is a RF for the development of asthma)
- Sinusitis (swelling of nasal mucosa leads to obstruction of sinus drainage)
- Nasal polyps
- Oral allergy syndrome
How does allergic rhinitis present
- Classical symptoms include: sneezing, itching, nasal discharge (rhinorrhoea) and nasal congestion- typically bilaterally and occurring within minutes following allergen exposure
- Additional symptoms include postnasal drip, itching of the palate and cough
- May get features of chronic nasal congestion- snoring, mouth breathing and halitosis (bad breath)
- May have a personal or family history of atopy (asthma, eczema, allergic rhinitis)
Signs:
* ‘Nasal intonation of the voice’
* Darkened eye shadows under the lower eyelid due to chronic congestion
* Horizontal nasal crease across the dorsum of the nose (seen in SEVERE rhinitis)
* Deviated or perforated nasal septum; depressed or widened nasal bridge.
* Nasal mucosa swelling and greyish discolouration (typically seen in allergic rhinitis); nasal polyps (rare in children); hypertrophic nasal turbinates (suggests inflammation); foreign bodies
* Purulent nasal discharge suggesting sinusitis
* Eye involvement suggesting allergic conjunctivitis
Investigations for allergic rhinitis
- Clinical diagnosis requires thorough history and examination
- Ask about the type, frequency, persistence, and location of symptoms (indoors or outdoors), the severity of symptoms and effect on daily life (sleep, school, behaviour etc.), housing situation (exposure to pets etc.), FHX and personal history of atopy, previous treatments and their effectiveness
- Skin prick testing may help to differentiate between allergic and non-allergic rhinitis (high negative predictive value)
Differentials for allergic rhinitis
- Infective rhinits (acute onset of symptoms of one week or less, associated with URTI symptoms)
- Non-allergic rhinitis (autonomic- symptoms typically follow a known physical exposure, including changes in termperature or humidity, chemical irritant exposure or with exercise)
Management of Mild-moderate intermittent or mild persistent symptoms
Must assess for atopy, including asthma, allergic conjunctivitis, eczema, food allergy
Refer to Itchy Wheezy Sneezy
Try to identify the most likely causative organism:
* Grass pollen allergy- avoid walking in grassy, open spaces etc.
* House dust mite allergy- Use synthetic pillows and acrylic duvets, and keep furry toys off the bed. Surfaces should be wiped regularly with a clean, damp cloth.
* Animal allergy- ideally not allow animal in the house or restrict to kitchen- wash the animal and any surface they’re in contact with regularly
Medication:
* Give ‘as-needed’ intranasal antihistamine as a first-line (azelastine), or a second-line, non-sedating oral antihistamine (loratadine) (nasal antihistamines have a faster onset of action) ONLY IN 6-17 years old
* If 2-5 years- give oral antihistamines (loratadine if over 2, cetirizine if younger than 2)
* Consider nasal irrigation with saline to rinse nasal cavity
* Could give an intranasal chromone such as sodium cromoglicate if antihistamines are poorly tolerated
Management of persistent moderate to severe uncontrolled asthma
- Examine for signs of severe rhinitis- (Deviated or perforated nasal septum; depressed or widened nasal bridge, nasal polyps, sinusitis)
- Prescribe a regular intranasal corticosteroid to be used during periods of allergen exposure (intranasal mometasone furoate).
- The onset of action is around 6-8 hours after the first dose, but maximal effect will not be seen until after 2 weeks
What steps should be taken after treatment failure
Check compliance with self-management strategies and initial drug treatment + review application technique
Consider an alternative diagnosis of non-allergic rhinitis
Consider stepping up treatment
* If nasal congestion is a problem, add in a short-term intranasal decongestant such as ephedrine or xylometazoline for up to 5–7 days (if over 6)
* Intranasal corticosteroid and oral antihistamine, add in an intranasal anticholinergic such as ipratropium bromide.
* For persistent itching or sneezing add in regular PO antihistamine rather than as needed
When can oral corticosteroids be considered
If the person has severe, uncontrolled symptoms that are significantly affecting quality of life (Prednisolone 10-15mg)
How should children with allergic rhinitis be followed up
- Consider referral to ENT if there are red-flag symptoms such as blood-stained discharge, nasal obstruction, refractory symptoms despite ongoing treatment, uncertain diagnosis
- Review all patients in 2-4 weeks after initiating any treatment to consider step-up treatment if symptoms persist.
