It's not uncommon to sweat when you eat hot or spicy foods. It just makes sense... if eating or drinking a specific food raises your body temperature, then your body will try to cool itself with sweating.
But some people sweat when they eat any kind of food (even ice cream) and some people sweat when they just think about food. Often called gustatory sweating or gustatory hyperhidrosis (and sometimes called Frey's syndrome), this food-related sweating can be extremely embarrassing and uncomfortable. Imagine yourself sweating excessively on your face and neck at a fancy restaurant while on a dinner date, or sweating as you wait for a business lunch to be served... Fortunately, treatment for gustatory sweating is possible, so don't throw away your Zagat's restaurant guide yet!
Many cases of gustatory sweating show up after surgery or trauma to a parotid gland. Most people have a pair of parotid glands, one located on each side of the face, below and in front of the external ear. The parotid glands are the body's largest salivary glands. Saliva, as you probably know, is a fluid secreted by salivary glands to aid chewing, swallowing, and digestion of food. Saliva is produced in preparation for eating (like when you are thinking about a delicious meal) as well as during chewing.
If a parotid gland is damaged or if surgery to a parotid is required (damage can occur due to inflammation, infection, and mumps, and tumors can require surgery), then related nerves may become damaged or may regenerate from such damage in a way that causes them to become "mixed up" and/or "intertwined" (so to speak). The result is that when a person is supposed to salivate, he or she may also sweat and experience facial flushing. This combination of sweating and flushing related to parotid trauma is called Frey's syndrome. Usually Frey's syndrome affects just one side of the face.
Gustatory sweating can also occur for no known reason (idiopathic) or related to another medical condition ("secondary hyperhidrosis" due to conditions such as diabetes, cluster headaches, Parkinson's, and facial herpes zoster or shingles). In these cases, the sweating is often experienced on both sides of the face and particularly on the temples, forehead, cheeks, neck, and/or chest, as well as around the lips. Redness and sweating may appear when an affected person eats, sees, thinks about, or talks about foods.
Gustatory sweating can be very distressing because the mere idea of food can make a patient's face drenched with sweat. And because much of life's business (friendships, romances, networking, and celebrations) is conducted at mealtime, gustatory sweating can have extensive social, economic, and emotional implications. Fortunately, there are treatments available and medical professionals can help. In particular, topical antiperspirants or Botox injections have been shown to provide significant relief. According to Dr. David Pariser (founding Member and Secretary of the International Hyperhidrosis Society as well as 2009 President of the American Academy of Dermatology), Botox injections can provide "a couple of years" of relief from gustatory sweating. This is a much longer duration of effectiveness than is typically seen when Botox is used to treat other forms of hyperhidrosis. (Please note, Botox has not been approved by the FDA for the treatment of gustatory sweating or Frey's syndrome so this is an "off-label" use of the medication. Off-label uses of medications are, however, very common.)
If you suffer from gustatory sweating, the first step is to try and figure out why. Your primary care physician can help you begin this process with a physical exam and thorough medical history. He or she may refer you to specialists if necessary.
Be sure to tell your doctor when and how much you sweat – Do some foods cause more problems than others? Where do you sweat? How much? How upset does this sweating make you? How does it affect your life and your relationships (at home and at work)? Do you sweat elsewhere on your body and at other times? Do you have other medical conditions? Have you ever had parotid surgery or mumps?
If your gustatory sweating is not due to another, treatable medical condition, then perhaps a dermatologist who specializes in hyperhidrosis is a good choice for "next steps." A medical professional, such as a dermatologist, can help you decide if a topical treatment (antiperspirant) or Botox is appropriate.
Sweat is not appetizing! Don't wait, you can get help for eating-induced hyperhidrosis.