Abstract:
BACKGROUND: Extension of the intervals at which
maintenance venom immunotherapy (MVIT) is administered
has been attempted for many years. However, published
evidence on its effect, especially in intervals of
longer than 3 months, is sparse.
OBJECTIVE: To examine
whether the administration of a bee venom (BV)
maintenance dose at 6-month intervals is safe and
efficacious.
METHODS: The 3-month intervals at which
venom-allergic patients were receiving their MVIT were
gradually extended to 6 months. Systemic reactions (SRs)
to immunotherapy injections or to field stings were
regularly recorded. Patients who were allergic to BV
alone or also to other venoms were deliberately sting
challenged by a honeybee after reaching the 6-month
interval.
RESULTS: The 3-month intervals were extended
in 47 patients. A single patient (2%) developed an SR
after receiving the injection at an interval of 4 months.
Two field stings in 2 patients resulted in a mild SR in
1 patient. Of 14 sting-challenged patients, 3 (21%)
developed an SR after the challenge. The 3 SRs occurred
only among the 8 patients (38%) who were allergic to BV
alone. The 3 patients with the SR to the challenge
continued to receive the regular maintenance dose at
monthly intervals 3 to 5 more times. Repeated sting
challenges were then well tolerated in all 3 patients.
CONCLUSION: The administration of MVIT at 6-month
intervals does not provide suitable protection in
BV-allergic patients, and they should continue MVIT at
the accepted 1- to 3-month intervals.
