Introduction
Mechanisms of immunotherapy
Indications
Indications: | • Patients with stinging insect (venom) hypersensitivity • Patients with allergic rhinitis/conjunctivitis and/or allergic asthma who have evidence of specific IgE antibodies to clinically relevant allergens; includes patients who: – Do not achieve control of symptoms with avoidance measures and pharmacotherapy – Do not want ongoing or long-term pharmacotherapy – Experience undesirable side effects with pharmacotherapy |
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Contraindications:
| • Patients on beta-blockers (relative contraindication with venoms) • Patients with uncontrolled or severe asthma • Significant co-morbid diseases such as cardiovascular disability |
Special considerations:
| • Children < 6 years of age • Pregnancy • The elderly • Patients with malignancy, immunodeficiency and autoimmune diseases |
Contraindications
Special considerations
Efficacy
Venom immunotherapy
Allergic rhinitis
Asthma
Patient selection
Venom hypersensitivity
Allergic rhinitis
Asthma
Immunotherapy administration and schedules
Tree pollen | Grass pollen | Weed pollen | Mould spores | |
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British Columbia (Coastal)
| • Season: early February to mid-July • Primarily deciduous trees (alder, birch, poplar, elm, oak) | • Season: end of April to September • Highest grass concentrations: early June to mid-July | • Not usually a major factor; no native ragweed | • Levels higher in the spring; increase further in September and October • Most prevalent spores: Cladosporium and basidiomycetes |
British Columbia (Interior)
| • Season: late March to mid-July • Primarily deciduous trees (willow, birch, poplar) | • Season starts in early May in southern parts of the province; starts up to 1 month later in northern parts | • Ragweed is minimal | • Cladosporium can occur from April to late fall |
Prairies
| • Season starts in the first week of April and continues through June• Main deciduous trees: birch and poplar; alder, maple, elm, oak, ash, and willow may also contribute | • Season starts in mid‐May and continues to the end of September• Peak season is usually mid‐June to early July | • Most common weeds: nettles or sage brush• Some ragweed, especially in Manitoba) | • Can occur through the spring, summer, and early fall• Alternaria and Cladosporium are the predominant moulds |
Ontario and Quebec
| • Season starts early April in southern Ontario and Quebec; may occur 6 weeks later in northern areas • In southern Ontario, most common are deciduous trees (birch, poplar, oak, maple, ash, elm, mulberry, willow, chestnut, hickory) • In northern Ontario, birch and poplar most common • In Quebec, ash, poplar, birch most common; maple, alder and oak are less prevalent | • Season starts mid-to-late May; a couple of weeks later in northern areas • Latter part of May and mid-June are peak seasons for grass pollination | • Ragweed season in Southern Ontario and Southwestern Quebec begins early-to-mid August • Reaches peak in late August/early September • Stops at first frost • Nettle and plantain can also contribute | • Occur during spring, summer and fall months • Concentrations may be higher late summer to fall months in Quebec • Alternaria and Cladosporium are the predominant moulds |
Maritimes
| • Season in New Brunswick and Nova Scotia: late March to last week of June • Primarily deciduous trees (birch, poplar, alder, maple, oak, and ash) | • Season: mid-May to end of September • Peaks in early June | • Ragweed: early August to end of September | • Levels higher during the late summer and early fall months • Alternaria and Cladosporium are the predominant moulds |
Safety
Signs/symptoms | Incidence |
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Urticaria, angioedema | 87% |
Dyspnea | 59% |
Dizziness, syncope | 33% |
Diarrhea, abdominal cramps | 29% |
Flushing | 25% |
Upper airway edema | 21% |
Nausea, vomiting | 20% |
Hypotension | 15% |
Rhinitis | 8% |
Itch without rash | 5% |
Seizure | 1% |
Conclusions
Key take-home messages
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Allergen-specific immunotherapy is a potentially disease-modifying therapy that is effective for the treatment of allergic rhinitis/conjunctivitis, allergic asthma and stinging insect hypersensitivity.
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Allergen immunotherapy is contraindicated in patients on beta-blockers, those with uncontrolled or severe asthma, or those with significant co-morbid cardiovascular disease.
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The decision to proceed with allergen immunotherapy should be made on a case-by-case basis, taking into account individual patient factors such as disease severity, efficacy of avoidance measures and pharmacological therapy, and patient preferences.
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Allergen immunotherapy carries the risk of anaphylactic reactions and, therefore, should only be prescribed by physicians who are adequately trained in the treatment of allergy
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Injections must be given under medical supervision in clinics that are equipped to manage life-threatening anaphylaxis.