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Oral Infection


Oral infection is a generalized term for a group of multiple infections occurring within your oral cavity. They can be of a dental origin (arising from your tooth) or a non-dental source (arising from other soft tissues). Viruses, bacteria, or fungi can cause these infections. In the majority of the cases, the basic problem that leads to oral infections is poor maintenance of oral hygiene. As plaque formation continues to build up around your teeth and on your tongue surface, the risk of damage to teeth and soft tissues increases. This can lead to severe complications if left untreated.


Based on their origin, oral infections are classified into dental and non-dental infections to simplify their understanding. The most common cause of dental infections is intraoral bacteria that penetrate the tooth structure or supporting tissues. These bacteria break down the enamel and cause inflammation of the pulp. Dental abscess formation can occur due to caries, incomplete root canal treatment, or infection in periodontal tissues. In severe cases, these infections can lead to swelling in the mouth and neck region (a condition known as Lugwig’s Angina).

Non-dental infections usually disrupt the soft tissue covering known as the mucous membrane. Viruses, bacteria, or fungi usually cause them. Viruses that cause oral infections include Herpes Simplex Virus, Herpes Zoster, Varicella-Zoster, Coxsackie A virus, and HIV. Cold sores are the most frequently occurring viral infection caused by Herpes Simplex Virus 1. Bacterial infections such as syphilis or tuberculosis can lead to ulcers within your oral cavity. The most common fungal infection is oral candidiasis caused by fungal overgrowth due to a weakened immune system. Other oral infections include lichen planus, infectious mononucleosis, histoplasmosis, hairy leukoplakia, blastomycosis, and coccidiomycosis. Oral infections can also occur due to dehydration, dry mouth, nutritional deficiencies, hormonal imbalance, genetic or autoimmune diseases, and weakened immune systems.

Risk Factors And Epidemiology

As mentioned earlier, one of the major risk factors for oral infections is poor oral hygiene. This increases the chance of tooth-related conditions and can also affect the surrounding soft tissues. Bacterial overgrowth from excessive plaque accumulation breaks down the tooth structure that results in tooth infection. They can also penetrate through the supporting structures of the tooth to cause dental abscess formation. Nutritional deficiencies, frequent dry mouth, stress or anxiety, diabetes, and hormonal imbalance increase the risk of oral infections. Another significant risk factor is a weakened immune system. This can occur in patients with immunocompromising diseases, those taking immunosuppressant medications, and those undergoing radiotherapy or chemotherapy.

Oral infections can occur at any age, depending on their cause. Dental infections have been noticed to be more common in children due to high sugar intake. Secondary oral infection occurring due to a weak immune system is more frequent in adults over the age of 40.

Signs And Symptoms

The signs and symptoms of oral infections depend on the cause of their origin. Viral infections can present with cluster-like lesions inside or outside the mouth. Bacterial and fungal infections can cause redness or ulceration within the oral cavity. If tooth structure is involved, the affected tooth will be painful, sensitive to hot and cold, and tender to percussion. Certain infections present with other extra-oral symptoms, including fever, swelling, headache, malaise, difficulty in biting and chewing, and dysphagia.


Diagnosis of oral infections requires a detailed history and a thorough clinical examination to identify the cause. Infections of dental origin are diagnosed by clinical evaluation, percussion, exposure to hot and cold stimuli, electric pulp test, and dental x-rays. Viral, bacterial, or fungal infections are generally diagnosed based on their presenting features. In some instances, a swab test might be necessary where a small sample is taken from the infected area to test for the pathogenic organism. Patients with secondary oral infections resulting from a weakened immune system will present a history of the primary disease, medication, or treatment that has lowered their immunity.

Differential Diagnosis

It is necessary to evaluate oral infections to differentiate them from other conditions that might present. These include pemphigus Vulgaris, erythema multiforme, Crohn’s disease, Bechet’s syndrome, Addison’s disease, melanoma, squamous cell carcinoma, and a few other diseases.


Depending on the cause, oral infections are treated symptomatically or with other procedures. Infections associated with a tooth, such as dental abscess, will require surgical incision and drainage. This is followed by a dental filling, endodontic treatment, crown placement, or extraction in severe cases. Viral infections usually do not require treatment except for symptomatic care. Bacterial infections need to be treated for the primary infections to cure oral symptoms. Fungal infections may require topical antifungal ointments or rinses with an antifungal mouthwash. Other infections are treated accordingly after accurate diagnosis of their causative agent.


Pain associated with oral infections can be managed by applying topical analgesics or anesthetics such as lidocaine, benzocaine, etc. If a tooth is hurting exceedingly, oral painkillers such as aspirin, diclofenac sodium, ibuprofen, etc., may be prescribed. Viral infections usually heal without medication within 10 to 14 days. Bacterial infections may require antibiotics such as penicillin, cephalosporin to reduce the symptoms. Fungal infections require topical antifungal gels or ointments containing nystatin, miconazole, etc.


The prognosis of most oral infections is good if they’re diagnosed earlier and treated accordingly. However, in severe dental cases, the infection might progress to a level where the extraction of the offending tooth is the only solution.



Basic prevention methods to reduce the occurrence of oral infections includes:

  • Maintaining oral hygiene
  • Brushing teeth twice daily
  • Flossing
  • Using antiseptic mouthwashes within the prescribed limit
  • Keeping mouth hydrated
  • Intake of necessary vitamins and minerals
  • Avoiding direct contact with an infected person
  • Avoid sharing toothbrushes and razors
  • Regular visits to your dentist after every six to eight months can also help reduce risk factors of oral infections.


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