Six months after a superficial parotidectomy, a 50-year-old woman reports sweating and flushing of the preauricular skin during meals. Which mechanism accounts for this complication?

• A Iatrogenic injury to the greater auricular nerve causing gustatory reflex sweating
• B Regeneration of chorda tympani fibres directly into dermal sweat glands
• C Denervation hypersensitivity of sympathetic receptors in the skin flap
• D Aberrant regeneration of parasympathetic fibres of the auriculotemporal nerve into sweat glands of the skin flap ✓

Explanation

This is Frey syndrome. Divided postganglionic parasympathetic secretomotor fibres travelling in the auriculotemporal nerve regenerate aberrantly into the sympathetic supply of sweat glands and cutaneous vessels, so gustatory stimuli produce sweating and flushing instead of salivation. The chorda tympani carries preganglionic fibres only as far as the otic ganglion and plays no cutaneous role, which defeats that tempting distractor. Botulinum toxin injection is now the standard treatment.

Reference: Cummings Otolaryngology Head and Neck Surgery, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.