Vaccination is a well-known trigger for mast cell degranulation in subjects affected by
mastocytosis. Nevertheless, there is no exact standardized protocol to prevent a possible reaction after a
vaccine injection, especially for patients who have already presented a previous
vaccine-related adverse event, considering that these patients frequently tolerate future
vaccine doses. For this reason, we aim to share our experience at Meyer Children's University Hospital in Florence to raise awareness on the potential risk for future vaccinations and to discuss the valuable therapeutic strategies intended to prevent them, taking into account what is proposed by experts in literature. We describe the case of an 18-month-old female affected by a polymorphic variant of
maculopapular cutaneous mastocytosis that presented an extensive bullous cutaneous reaction 24 hours after the second dose (booster dose) of inactivated-tetravalent
influenza vaccine, treated with a single dose of oral
corticosteroid therapy with
betamethasone (0.1 mg/kg) and an oral
antihistamine therapy with
oxatomide (1 mg/kg/daily) for a week, until resolution. To the best of our knowledge, in the literature, no documented case of reaction to
influenza vaccine in
maculopapular cutaneous mastocytosis is described. Subsequently, the patient started a background
therapy with
ketotifen daily (0.05 mg/kg twice daily), a non-competitive H1-antihistamine, and a
mast cell stabilizer (dual activity). A non-standardized pharmacological
premedication protocol with an H1-receptor antagonist (
oxatomide, 0.5 mg/kg) administered 12 hours before the immunizations, and a single dose of
betamethasone (0.05 mg/kg) together with another dose of
oxatomide (0.5 mg/kg) administered 2 hours before the
injections was followed to make it possible for the patient to continue with the scheduled vaccinations. Indeed, no reactions were subsequently reported. Thus, in our experience, a background
therapy with
ketotifen associated with a
premedication protocol made by two doses of
oxatomide and a single dose of
betamethasone was helpful to make possible the execution of the other
vaccines. We suggest how in these children, it could be considered the idea of taking precaution when vaccination is planned, regardless of the kind of
vaccine and if a dose of the same
vaccine was previously received. However, international consensus needs to be reached to manage vaccinations in children with
mastocytosis and previous adverse reactions to
vaccines.