Allergen-specific immunotherapy in hay fever

Allergen-specific immunotherapy is effective and can be of lasting benefit to patients with seasonal allergic rhinitis (1).

Immunotherapy is a process that involves the administration of increasing doses of a specific allergen extract over months to years, to relieve symptoms associated with subsequent exposure to that allergen

• allergen-specific immunotherapy should only be undertaken by a clinician experienced in its use, as it is associated with a small risk of anaphylaxis. This is particularly the case during induction or the upward dose titration phase
• allergen-specific immunotherapy should be reserved for patients who have poorly controlled symptoms and/or evidence of clinically relevant IgE-mediated disease (despite allergen avoidance and use of appropriate medication such as antihistamines etc)

Notes

• "the Committee on Safety of Medicines has advised that patients with hay fever and persistent asthma should not be treated with allergen-specific immunotherapy - this is because they are at greater risk of developing severe adverse reactions than other patients (1)"
• use of sublingual immunotherapy rather than traditional subcutaneous injection immunotherapy
  • there is evidence that sublingual immuotherapy with a grass allergen tablet is effective in seasonal allergic rhinoconjunctivitis - this therapy is well tolerated and can reduce symptoms and improve quality of life. No safety concerns were observed (2)
  • data show that sublingual immunotherapy with grass allergen tablets improves quality of life in allergic rhinoconjunctivitis, reduces symptoms, and that this effect is greater than rescue antihistamine alone (3)
• Grazax is a once-daily sublingual tablet containing allergen extract of grass pollen (4)
  • it is licensed for adults with clinically relevant symptoms of pollen allergy who have been diagnosed with a positive skin prick test and/or specific IgE test to grass pollen
  • should be initiated by physicians with experience in the treatment of allergic disease. In view of the possibility of local or systemic allergic reactions when first taken, the first dose should be taken under medical supervision (20-30 minutes).

Reference:

1. MeReC bulletin 2004;14 (5):17-20.
2. Durham SR et al. Sublingual immunotherapy with once-daily grass allergen tablets: a randomized controlled trial in seasonal allergic rhinoconjunctivitis. J Allergy Clin Immunol. 2006 Apr;117(4):802-9.
3. Rak S et al. Once-daily sublingual allergen-specific immunotherapy improves quality of life in patients with grass pollen-induced allergic rhinoconjunctivitis: A double-blind, randomised study. Qual Life Res. 2007 Mar;16(2):191-201
4. MeReC Extra March 2007.