What is one hallmark symptom of Frey's syndrome?

Frey's syndrome, also known as gustatory sweating, is characterized by excessive sweating in the area of the cheek, particularly during eating or the anticipation of eating. This phenomenon occurs due to aberrant regeneration of the facial nerve (particularly the auriculotemporal branch) after injury, leading to the miscommunication between the salivary gland and sweat glands in the parotid region. As a result, stimulation of the salivary glands during meals inadvertently triggers sweating on the cheek, classifying focal hyperhidrosis as the hallmark symptom of this syndrome. The presence of this specific symptom is distinctive and allows for the diagnosis of Frey’s syndrome.