Hayfever

List the newer antihistamines

Acrivastine (12+) Cetirizine (6+) Loratidine (2+)

What are the treatments for hay fever?

Antihistamines Steroid nasal spray to treat moderate-severe nasal symptoms (18+): Fluticasone (pirinase) Beclometasone (beconase) Eye drops: Sodium cromoglicate (opticrom) Xylometazoline/antazoline (otrivine antistin) Nasal decongestants

List the older antihistamines

Chloramphenamine (Pirton 6+, 1+ for liquid) Promethazine Hal (Phenergan)

What are the cautions for antihistamines?

Epilepsy (Increases risk of seizures) BPH (urinary retention) Susceptibility to angle-closure glaucoma (raises intracranial pressure) Urinary retention

What lifestyle advice can be given to patients who have hayfever?

Hayfever: Close windows and stay indoors when pollen count is high Use 'wrap around' sunglasses Avoid grassy fields, parks and gardens Perennial allergic rhinitis: Exclude pets from areas of the house e.g. bedroom Acaricide sprays can kill house mites Strict bedroom cleaning regime to prevent dust

What is the mechanism of action of sodium cromoglicate?

Mast cell stabiliser, inhibiting the release of histamine and various membrane derived mediators from the mast cell.

Describe the onset of action of steroid nasal sprays

May take a few days to work

What are the contraindications for sedating antihistamines?

Patients taking MAOI - (avoid 14 days after stopping MAOI)

What causes perennial allergic rhinitis?

People with perennial allergic rhinitis experience symptoms year-round. It is generally caused by dust mites, pet hair or dander, cockroaches, or mold. Underlying or hidden food allergies rarely cause perennial nasal symptoms.

What are the referral criteria for hay fever?

Signs of asthma attack: Chest tightness Wheezing (difficultly breathing) Shortness of breath Cough Purulent conjuctivitis (?eye infection) Painful ear/sinuses (?secondary infection)

What are the symptoms of allergic rhinitis?

Runny, itchy nose/nasal congestion Sneezing itchy, watery eyes Itchiness

What are the side effects of antihistamines?

Sedation - more common with older antihistamines Anti-cholinergic - more common with older antihistamines (blurred vision, dry mouth, urinary retention, constipation)

What is the mechanism of action of xylometazoline?

Sympathomimetic, constricts blood vessels in the eye to reduce redness

What causes seasonal allergic rhinitis?

Symptoms of seasonal allergic rhinitis can occur in spring, summer, and early fall when pollen count is high. They are usually caused by allergic sensitivity to airborne mold spores or to pollens from trees, grass, and weeds.

What are the benefits of antihistamines used in hay fever?

The anticholinergic effect is useful to treat watery eyes and a runny nose (they will dry up secretions)

What is the mechanism of action of antazoline?

Topical antihistamine which directly inhibits histamine receptors in the eye

What are the types of allergic rhinitis?

seasonal and perennial