Frey's syndrome

Overview

Frey's Syndrome, also known as auriculotemporal syndrome, is a neurological disorder characterized by sweating, flushing, or warmth of the facial skin in the area near the ear (preauricular region) while eating or thinking about food. This condition most commonly occurs after surgery or trauma to the parotid gland, the largest of the salivary glands. It results from abnormal nerve regeneration, leading to the miswiring of nerves responsible for salivation and those controlling sweat glands in the skin.

Causes

The primary cause of Frey's Syndrome is damage to the auriculotemporal nerve, often due to surgical procedures involving the parotid gland, such as:

• Parotidectomy (removal of the parotid gland)

• Facial trauma

• Infections affecting the parotid area

• Other head and neck surgeries

Following nerve injury, regenerating parasympathetic fibers (which usually stimulate saliva production) may erroneously connect to nearby sweat glands in the facial skin, resulting in sweating and flushing during meals—phenomena collectively known as "gustatory sweating."

Symptoms

The hallmark symptoms of Frey’s Syndrome typically appear months after nerve injury or parotid surgery and include:

• Facial sweating on one side of the face during or just before eating

• Flushing or redness of the skin in the same region

• Sensation of warmth or tingling in the affected area

• Symptoms limited to the area in front of and below the ear

• Possible extension to the cheek and temple area

These symptoms are usually unilateral (one-sided) and often become more pronounced when consuming spicy, sour, or aromatic foods.

Diagnosis

Diagnosis of Frey’s Syndrome is based on clinical history and physical examination. Specific diagnostic tests include:

• Minor’s starch-iodine test: A reliable and commonly used method. Iodine is applied to the skin, followed by starch powder. When the individual eats or thinks about food, areas of sweating turn blue or purple, confirming the presence and extent of gustatory sweating.

• Patient history: Prior surgery or trauma to the parotid gland area is a key clue.

• Observation of symptoms: Symptoms that consistently occur with eating strongly support the diagnosis.

Treatment

Treatment of Frey’s Syndrome depends on symptom severity. Many mild cases do not require intervention. Options include:

Non-Surgical Management

• Topical antiperspirants (e.g., aluminum chloride): May reduce sweating in mild cases.

• Botulinum toxin (Botox) injections: A highly effective treatment that temporarily blocks nerve signals to sweat glands. Effects last for 6 to 12 months and can be repeated.

Surgical Management

• Reserved for severe or persistent cases.

• Procedures may include tympanic neurectomy or placement of a tissue barrier between the skin and parotid bed during surgery to prevent nerve miswiring.

Prognosis

The prognosis for Frey’s Syndrome is generally good, especially when symptoms are mild. Many patients adapt to the condition without requiring treatment. For those with more bothersome symptoms, botulinum toxin injections provide effective relief. Surgical options are available but are rarely needed. The syndrome is not dangerous but can cause social discomfort and self-consciousness, particularly when facial sweating is obvious. With proper management, most individuals can achieve significant symptom control.