My daughter has been diagnosed with Frey's syndrome. I would like to know how rare this condition is, if there are any associated health complications, and also if she will have this condition for life.
Frey's Syndrome is a rare neurological disorder that results from injury or surgery near the parotid glands (which manufacture saliva), damaging the facial nerve. The parotid glands are the largest salivary glands and are located on the side of the face below and in front of the ear. This syndrome is characterized by flushing or sweating on one side of the face when certain foods are consumed. The symptoms usually are mild and well tolerated by most individuals. Relief from symptoms may require treatment in some cases. 
Last updated: 5/25/2011
How common is Frey's syndrome in children?
Frey's syndrome in children is rare.  Although no exact incidence is known, one article states that only 68 cases have been reported as of publishing in April 2010. 
Last updated: 1/16/2013
What is the prognosis for a child with Frey's syndrome?
Frey's syndrome symptoms may persist indefinitely but are usually mild and well tolerated by most individuals.  Some reports indicate that symptoms of this condition can resolve on their own over time. 
Last updated: 6/10/2011
We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please
Martinez-Baylach J, et al. Frey's sydrome secondary to an obstetrics trauma: Presntation of 2 cases and a review of the literature. Anales en Pediatria. April 2010; http://www.ncbi.nlm.nih.gov/pubmed/20188641. Accessed 1/10/2011.