Case Description
A previously healthy four-year-old female with a new diagnosis of grade
IV primitive neuroectodermal (PNET) brain tumor underwent surgical
resection and came to our institution for chemo-radiation as standard of
care. The patient was scheduled to receive vincristine during radiation
therapy. During her initial infusion of vincristine she developed an
anaphylactic reaction with facial flushing, cough, lip swelling and
oxygen desaturation to 87% at room air within 3 minutes of starting the
infusion. The infusion was stopped and the patient was given a dose of
diphenhydramine and hydrocortisone, which abated her symptoms.
An extensive root cause analysis was done to determine the cause of the
allergic reaction, since anaphylaxis to vincristine is rare. In the
following 2 weeks the patient had similar anaphylactic reactions while
receiving IV pentamidine and premedication with IV hydrocortisone,
proving that anaphylaxis was not due to vincristine. The patient did not
experience any reaction to saline flushes, chlorhexidine or alcohol
wipes.
Our work up for multiple allergic reactions included complement levels,
antibodies for rheumatologic and autoimmune diseases and thyroid
function tests. Thyroid stimulating hormone (TSH) was elevated at 7.3
mcunit/mL (normal reference 0.27 - 4.20). No eosinophilia or
immunodeficiency was detected in the work up and immunoglobulin levels
were unremarkable. The patient was referred to endocrinology and a
complete work up showed elevated prolactin 50.1 ng/mL (4.8 - 23.3 ng/mL)
which was secondary to TSH elevation. The patient also had clear
rhinorrhea for which an upper respiratory viral panel was sent and this
was negative. She was diagnosed as having allergic rhinitis, a common
co-exiting condition with Hashimotos thyroiditis, for which cetirizine
was started with moderate improvement of her symptoms.
Further work up by endocrine team revealed elevated thyroid peroxidase
antibodies at 29.8 IU/mL (reference range: 0.2 - 8.9 IU/mL) with
subsequent normalization of TSH and Free T4 which was consistent with
the diagnosis of Hashimoto thyroiditis.
The consistency found between all the allergic reactions was the IV
tubing set used. When we changed from low sorb tubing to regular tubing,
the patient did not experience any further allergic reactions to
chemotherapeutic and non-chemotherapeutic agents, without the use of
premedication. She was able to successfully receive additional doses of
vincristine and proceed with maintenance chemotherapy as standard of
care for PNET. The patient was referred to allergy and immunology for
further work up but there were no significant findings.