Can Frey syndrome be congenital and bilateral

Frey syndrome can indeed be congenital and may present bilaterally, although this is uncommon and considered rare. While the condition most frequently occurs following surgical trauma to the parotid or neck regions or in association with diabetes mellitus, a distinct subset of cases arises in pediatric populations without antecedent surgery or systemic disease, suggesting congenital or perinatal origins.

Systematic review evidence demonstrates that approximately 17% of Frey syndrome cases without history of surgery or diabetes present bilaterally, and in about one-third of these non-surgical cases, no definitive cause is identified. Many bilateral cases fall into this idiopathic group, which raises the possibility of prenatal or congenital factors contributing to these presentations Betti et al. 2022.

The most frequent identifiable cause in congenital or early-onset cases is a history of forceps-assisted vaginal delivery, which likely causes perinatal trauma to the auriculotemporal nerve and consequent aberrant reinnervation. However, bilateral cases are disproportionately represented among those with no known cause, supporting a congenital or developmental basis in some instances Betti et al. 2022.

Therefore, congenital Frey syndrome is plausible and can manifest bilaterally, though it is considered rare compared to the more common postsurgical unilateral presentations. The diagnosis in infants and children should be distinguished from food allergy by its characteristic preauricular erythema occurring within seconds of mastication and resolving rapidly, without systemic allergic features Betti et al. 2022.

This contrasts with the common adult presentations of Frey syndrome, which are largely unilateral and secondary to surgery or trauma Mantelakis et al. 2021. The congenital or bilateral presentations underscore the need for careful history taking and awareness to avoid misdiagnosis and unnecessary allergy investigations or dietary restrictions.