2. Case report
A 77-year-old patient was admitted for a left ureteroileoplasty. During
anesthetic induction, he presented hypotension after mechanical
ventilation treated with epinephrine from which he recovered, and when
receiving prophylactic antibiotic therapy with 2 grams of
amoxicillin/clavulanic acid (AC) intravenously he developed diffuse
urticaria with bronchospasm, followed by cardiac arrest within 2
minutes. Cardiopulmonary resuscitation was successful, and the patient
required 6 mg of intravenous epinephrine, external electric shock, 11
puffs of salbutamol and 100 mg of hydrocortisone. Serum biomarkers were
obtained and elevated tryptase and histamine levels confirmed mast cells
and possibly basophils activation and degranulation during anaphylaxis
(Table I ). The surgical procedure was not performed, and the
patient was transferred to the intensive care unit for recovery and
monitoring. Allergy to amoxicillin or clavulanic acid was suspected. On
day 3 after the event, he developed pneumonia and 1 g of oral
amoxicillin/clavulanic acid was administered without symptoms. As the
prescribing error was quickly identified, no additional doses were
administered, and the antibiotic therapy was replaced by levofloxacin.
The patient was informed of the prescribing error.
The allergology consultation carried out four weeks later revealed that
the patient had been taking amoxicillin (3 grams/day for 4 days), which
had been well tolerated one month before the event, due to urinary tract
infection. Skin prick tests (SPTs) and intradermal skin tests (IDTs) for
amoxicillin, amoxicillin/clavulanic acid, cefazolin,
piperacillin-tazobactam and cefotaxime; SPT for latex and basophil
activation tests (BATs) (expression of CD63/CD203c by flow cytometry)
for amoxicillin, amoxicillin/clavulanic acid, cefazolin,
piperacillin-tazobactam and cefotaxime were performed. The results
confirmed an IgE-mediated allergy to amoxicillin (Table II ):
IDTs and BATs were positive for amoxicillin and amoxicillin/clavulanic
acid and negative to all other drugs. A challenge with 3000 mg of
piperacillin-tazobactam was negative.
Amoxicillin and clavulanic acid were considered responsible for the
per-operative anaphylactic shock, and the diagnosis of post-anaphylactic
mast cell anergy was proposed to explain the absence of clinical
reaction to the reintroduction of 1 gram of amoxicillin/clavulanic acid
on day 3 after anaphylaxis.