Postherpetic gustatory flushing and sweating.

An 11-year-old girl who had suffered right facial herpes zoster at the age of 6 years was left with anesthetic scars in the distribution of the third division of the trigeminal nerve. Since then, certain tastes provoked flushing and sweating localized to the scarred areas, lasting for 10 to 15 minutes after a latency of a few seconds. The response was evoked most readily from the ipsilateral posterior section of the tongue and was virtually abolished by local administration of anesthesia to the tongue. It remained unaltered after blockade of the sphenopalatine and stellate ganglia but was diminished by blockade of the mandibular nerve. Thermoregulatory sweating and flushing were diminished in the scarred areas. Patchy destruction of sympathetic fibers, which are known to accompany peripheral trigeminal nerve branches, and reinnervation of the affected areas by parasympathetic fibers that normally mediate salivation may explain the phenomenon. It is thus analogous to the gustatory flushing and sweating that may follow damage to the auriculotemporal nerve in the region of the parotid gland (Frey's syndrome).