An itchy mouth is a common symptom of viral or fungal infections. It also frequently occurs during allergic reactions.
Itchiness within the mouth can range from mild to severe, depending on the underlying issue.
In this article, we explore the causes of an itchy mouth. We also describe treatment options, strategies for prevention, and when to see a doctor.
Several conditions can cause itchiness within the mouth, including the following:
Oral allergy syndrome
Oral allergy syndrome (OAS) is a type of food allergy that affects the mouth, lips, tongue, and throat. It occurs in people with pollen allergies.
Proteins in specific foods can be very similar to proteins in certain pollens. In a person with OAS, the body reacts to proteins in these foods as though they were proteins in pollen allergens. This misidentification could result in a new allergic reaction or cause existing allergy symptoms to intensify.
According to the American Academy of Allergy, Asthma & Immunology, OAS affects 50–75% of adults who are allergic to birch tree pollen.
Tingling and itching in the mouth are among the most common symptoms of food allergies, according to a 2015 small-scale review.
Other symptoms of OAS can include:
- a scratchy throat
- red, itchy bumps called hives that develop in the mouth or throat
- swelling of the lips, tongue, or throat
Foods that can cause OAS reactions include:
- fish and shellfish
- cow's milk
Anaphylaxis is another allergic reaction, but it is far more serious than OAS and requires immediate medical attention. People are at risk of anaphylaxis when their immune system becomes hypersensitive to acute allergens, such as bee stings, pollen, and certain foods.
Anaphylaxis affects the entire body and can cause low blood pressure and severe swelling. The dramatic drop in blood pressure can starve the organs and tissues of oxygen.
The swelling can affect the mouth and throat, making it difficult or even impossible to breathe.
Symptoms of anaphylaxis include:
- itching or tingling of the mouth and throat
- rapid heartbeat
- nausea or vomiting
- difficulty breathing
- loss of consciousness
Viruses that attack the upper respiratory tract, such as those responsible for the common cold or flu, can cause an itchy mouth.
When a person gets a viral infection, the immune system sends specialized cells to capture and destroy the invading pathogens.
The buildup of immune cells can lead to inflammation and congestion, which can cause the roof of the mouth and the throat to feel itchy.
Viral infections can cause the following symptoms:
Oral thrush is a fungal infection that occurs due to an overgrowth of Candida yeasts in the mucous membranes that line the mouth and throat.
Oral thrush causes thick, cream-colored patches on the tongue, inner cheeks, roof of the mouth, and throat. People may experience itching, burning, or general discomfort in the affected areas.
Other symptoms of oral thrush include:
- dry mouth
- soreness in the affected areas
- loss of taste
- pain while eating or swallowing
The Centers for Disease Control and Prevention (CDC) state that the following factors can increase a person's risk of developing oral thrush:
- wearing dentures
- taking antibiotics
- taking corticosteroids, including those in asthma inhalers
- having diabetes
- having a weakened immune system
Treatment options for an itchy mouth vary depending on the cause.
Treatments for allergic reactions
A mild allergic reaction may clear up on its own, either after the person spits out the food that is causing the reaction or once their body has finished digesting the allergenic proteins.
People can also take medications called antihistamines to treat symptoms such as:
A severe allergic reaction, such as anaphylaxis, requires immediate treatment. A person having a severe reaction can self-administer medication using an epinephrine auto-injector, sometimes called an EpiPen.
Epinephrine is a hormone that increases blood flow and relaxes the smooth muscles, which opens up the airways, helping a person breathe.
Treatments for oral thrush
A doctor is likely to prescribe or recommend antifungal medications to treat oral thrush. Some examples include:
- clotrimazole (Canesten)
- miconazole (Monistat)
- nystatin (Mycostatin)
- fluconazole (Diflucan)
Anyone who thinks that they have an infection in their mouth should see a doctor.
If a person thinks that they could have a particular allergy, they can schedule an allergy test. During this test, a healthcare professional will scratch or prick the skin and introduce a small sample of the allergen into the area. If the person is allergic to the substance, their body will react.
Allergy tests help identify specific allergens to avoid. A doctor can use the results to make a diagnosis and, possibly, prescribe epinephrine.
A physical examination and a culture test help a doctor diagnose oral thrush. During a culture test, a doctor often uses a cotton swab to collect a small sample from the patches in the mouth, which goes to a laboratory for analysis.
The doctor may also request a blood test to rule out any underlying conditions.
People can prevent allergic reactions by avoiding known allergens.
Preventing oral thrush can involve improving oral hygiene and making some lifestyle changes, such as:
- removing dentures at night
- rinsing the mouth after using corticosteroid inhalers
- brushing and flossing the teeth regularly
- quitting smoking or avoiding secondhand smoke
An itchy mouth often results from a mild food allergy or an infection.
In the case of an allergy, the itchiness usually goes away when a person stops eating the food responsible for the reaction.
However, an itchy mouth can also be a symptom of a more severe and sometimes life threatening allergic reaction called anaphylaxis. Anyone experiencing anaphylaxis will need immediate medical treatment.