Facial Swelling with Influenza
Yes, facial swelling can occur with influenza, though it is uncommon and typically presents in two distinct contexts: as part of Oculorespiratory Syndrome (ORS) following influenza vaccination, or rarely as acute sialadenitis during active influenza A infection.
Facial Swelling After Influenza Vaccination
The most well-documented association between facial swelling and influenza involves post-vaccination reactions, specifically ORS:
ORS presents with facial edema (or facial swelling) along with bilateral red eyes and respiratory symptoms within 2-24 hours of receiving influenza vaccine, resolving within 48 hours of onset 1.
This syndrome was first described during the 2000-01 influenza season in Canada and was strongly associated with one specific vaccine preparation (Fluviral S/F) not available in the United States 1.
The cause of ORS has not been established, but studies demonstrate it is not IgE-mediated, distinguishing it from true allergic reactions 1.
After manufacturing process changes in 2000-01, the incidence of ORS was greatly reduced 1.
Facial Swelling During Active Influenza Infection
Facial swelling can occur as a complication of active influenza infection, though this is rare:
A case series from the 2017-2018 influenza season documented four patients presenting with severe neck and facial swelling due to acute sialadenitis (salivary gland inflammation) associated with influenza A infection 2.
While isolated case reports of sialadenitis with influenza A had been previously documented, this cluster represented a notable presentation during that particular flu season 2.
This represents a distinct entity from the typical clinical presentation of influenza, which classically includes abrupt onset of fever, cough, chills, myalgias, and malaise 3, 4.
Clinical Differentiation
When evaluating facial swelling in the context of influenza, the timing and associated symptoms are critical:
Post-vaccination facial swelling (ORS) occurs within 2-24 hours of vaccine administration, includes bilateral red eyes and respiratory symptoms, and resolves within 24-48 hours 1, 5.
Infection-related facial swelling presents during active influenza illness, may be unilateral or bilateral depending on which salivary glands are affected, and represents a complication requiring specific evaluation 2.
Important Clinical Caveats
Persons with mild upper facial swelling after influenza vaccination without other concerning signs of hypersensitivity can receive future influenza vaccines without further evaluation 1.
Do not confuse ORS with true IgE-mediated hypersensitivity reactions, which would present with generalized urticaria, wheezing, swelling of mouth and throat, difficulty breathing, or hypotension 1.
If uncertain whether post-vaccination symptoms represent true hypersensitivity, seek consultation from an allergist/immunologist before future vaccination 1.
During active influenza infection, facial swelling warrants evaluation for complications such as sialadenitis, particularly if the swelling is severe or progressive 2.