Frey syndrome (synonyms: Auriculotemporal syndrome; Frey-Baillarger syndrome; Frey’s syndrome; Gustatory sweating; Gustatory hyperhidrosis; Frey’s disease; ICD:10-GM G50.8: Other diseases of the trigeminal nerve) refers to profuse sweating in defined areas of skin on the face and neck, triggered by gustatory stimuli (taste stimuli) such as chewing, tasting, or biting.
The Polish neurologist Lucja Frey-Gottesmann described the condition in 1923 and was also the eponym of this syndrome.
Symptoms – complaints
Affected patients complain of sweating in the cheek area, which occurs whenever saliva is normally produced. It usually takes only one to two minutes after a gustatory stimulus for the sweating to occur. Other possible symptoms include tingling or burning of the skin, as well as redness and a feeling of swelling in the affected skin area. The areas most commonly affected are the supply areas of the auriculotemporal nerve or the auricularis magnus nerve.
Pathogenesis (disease development) – etiology (causes)
The nerve branch “Chorda Tympani” of the seventh cranial nerve “Nervus facialis” (facial nerve) serves the salivary secretion. Parasympathetic nerve impulses originate from it, which normally address the salivary glands. In Frey’s syndrome, however, there is a misdirection in the nervous system. Instead of targeting their actual target organ, the nerve impulses dock onto the sweat glands. Thus, whenever a stimulus to produce saliva occurs, sweat is secreted.
Possible causes are:
- Complete or partial removal of the parotid gland (parotid gland) – symptomatology usually occurs months later
- Peripheral facial paresis (facial paralysis).
- Inflammation of the parotid gland or the submandibular gland (submandibular gland)
- Removal of cervical lymph nodes
Follow-up
There are no known sequelae.
Diagnostics
To demonstrate the extent of sweating, Minor’s iodine-starch test is performed. In this test, the area of skin over the parotid region is first smeared with a solution containing iodine and then dusted with starch powder. Subsequently, something to eat is given to produce a gustatory stimulus. Blue staining can be used to identify which area is affected by gustatory sweating.
Therapy
There have been many attempts to treat Frey syndrome, both surgically and medicinally. One has been to try to cut secretory nerve fibers to prevent their sprouting into the sweat glands of the skin. Another surgical approach has been to spatially separate the nerves from the sweat glands of the skin by interposition of muscle, fascia, or alloplastic material. Agents for application are anticholinergics such as scopalamine or antyhyperhidrotica, but they are only effective for a short time and must be reapplied repeatedly. Today, the injection of botulinum toxin A has proven to be an effective therapy. After iodine-starch text has been performed, the affected skin area is marked and botulinum toxin is injected. Depending on the study, it has been reported that patients benefited from the injections for more than a year, in that symptoms were greatly diminished or absent.
