Duration of Treatment
ÎThe patient's response to immunotherapy should be evaluated on a regular basis. A decision about continuation of effective immunotherapy should generally be made after the initial period of 3 to 5 years of treatment. Some patients might experience sustained clinical remission of their allergic disease after discontinuing immunotherapy, but others might relapse. The severity of disease, benefits sustained from treatment, and convenience of treatment are all factors that should be considered in determining whether to continue or stop immunotherapy for any individual patient. (D)
Local and Systemic Reactions
ÎPublished studies indicate that individual local reactions do not appear to be predictive of subsequent systemic reactions. However, some patients with a greater frequency of large local reactions might be at an increased risk for future systemic reactions. (C)
ÎLocal reactions were found not to predict local reactions at the next injection in a retrospective study. (C)
ÎGlycerin concentrations of up to 50% were not associated with significantly higher local reaction rates. Higher glycerin concentrations are associated with injection pain, which correlates with the total amount of glycerin injected. (C)
ÎAlthough there is a low risk of severe systemic reactions with appropriately administered allergen immunotherapy, life-threatening and fatal reactions do occur. (A)
ÎThe majority of safety data on allergen immunotherapy reactions are in the context of 30 minutes. Because most serious systemic reactions from allergen immunotherapy occur within 30 minutes after an injection, patients should remain in the physician's office/medical clinic for at least 30 minutes after the immunotherapy injection. (C)
ÎDelayed systemic reactions, defined as occurring after the 30-minute wait period, can occur and, in general, are not severe. (B)
ÎBiphasic immunotherapy reactions, defined as resolution of the initial reaction with recurrence at 2 to 24 hours, were reported in up to 23% of patients who experienced a systemic reaction after allergen immunotherapy in one study. Biphasic reactions were typically less severe than the initial reaction. (C)
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