What is Bacterial Infections of the Oral Mucosa (Oral Infections)?
The mouth houses a variety of different microorganisms that usually exist in balance. An upset in this balance or the introduction of new virus, fungus, or bacteria can lead to an infection in the mouth and its inner lining.
Normally, it’s hard for bacterial infections to start in the mouth because of the protective role of the mouth lining, the antibacterial aspects of saliva, and the body’s immune responses. However, if the mouth lining is disturbed due to bad oral hygiene, injury, smoking, excessive alcohol use, or other factors, the likelihood of bacterial infections increases. This is especially true for people with weaker immune systems, such as those with HIV, cancer, or ongoing steroid therapy.
This overview will explain the mouth-related aspects of the most common bacterial infections that can affect the mouth’s inner lining. These include sexually transmitted diseases like syphilis and gonorrhea, a granulomatous disease named tuberculosis, and scarlet fever, which mostly affects young children.
What Causes Bacterial Infections of the Oral Mucosa (Oral Infections)?
Syphilis is a disease caused by a spirochete, a type of bacteria called Treponema pallidum. It can be passed through sexual contact or from a pregnant mother to her baby, which is termed as congenital syphilis. The disease typically develops within 20 to 40 days after exposure. The only organism that carries this bacteria is humans; animals do not carry it.
Gonorrhea is a sexually transmitted disease caused by bacteria called Neisseria gonorrhoeae. It mainly causes inflammation of the urethra in men and cervix in women. Sometimes, this bacteria can infect the throat, although it’s less common. This usually happens in women or men who have sex with men. The bacteria can struggle to survive in saliva, but it can be passed during oral sex or kissing from a person who has no symptoms.
Tuberculosis is caused by a type of bacteria called Mycobacterium tuberculosis. While it primarily affects the lungs, it can also spread to the mouth through the bloodstream. The bacteria can be spread in the air from a sick person’s cough, sneeze, or speech, and it can hang in the air for hours. Even though the risk of catching tuberculosis at a dental clinic is quite low, it can still happen – particularly with patients from areas of the world where the disease is common or in those with a reactivation of a TB infection.
Scarlet fever is an infection that generally arises in people who are suffering from a sore throat due to bacteria or from certain skin infections. The bacteria that causes it is Streptococcus pyogenes, which is a type of “Group A beta-hemolytic streptococci.” It usually takes 2 to 5 days to start showing symptoms once exposed to the bacteria. The disease can be passed easily from one person to another through saliva or nasal fluids, especially in packed places like daycare centers and schools.
Risk Factors and Frequency for Bacterial Infections of the Oral Mucosa (Oral Infections)
Oral symptoms can be seen in about 4 to 12% of people with syphilis, usually detected during the secondary phase of the disease. The average age for a syphilis diagnosis is 34, with men accounting for 51% of the cases. Gonorrhea is typically diagnosed through urogenital tests, but many clinics don’t offer screenings for oropharyngeal gonorrhea in the mouth and throat.
- For men who have sex with men, the prevalence of oropharyngeal gonorrhea is between 2% and 11%.
- For heterosexual men, the rate is between 3% and 7%.
- For women, the rate is between 2% and 10%.
Routine screening of asymptomatic individuals at risk for gonorrhea has shown that throat and rectal gonorrhea infections are common.
Tuberculosis is more prevalent in developing countries, with over 80% of cases in 2019 recorded in countries like Indonesia, India, China, the Philippines, Pakistan, Bangladesh, Nigeria, and South Africa. Most oral signs of this disease occur secondary to a primary lung infection. Still, young patients can get primary oral tuberculosis through direct contact with the bacteria in the oral mucosa. About 1 to 5% of people with tuberculosis have oral symptoms, and 1.33% of these cases are linked with infections like HIV that weaken the immune system.
Scarlet fever can affect people of all ages but is more common in children aged 5 to 15. Strep throat is responsible for 15 to 30% of all throat infections in children and 5 to 15% in adults. So, scarlet fever is more prevalent amongst children, especially in less developed countries where living conditions can be crowded.
Signs and Symptoms of Bacterial Infections of the Oral Mucosa (Oral Infections)
Syphilis is a sexually transmitted disease with different stages characterized by different symptoms. The first sign of syphilis typically is a sore in the mouth, known as a chancre. This normally develops about two weeks after exposure and is most often seen on the inside of the cheeks, tongue, or lips. This sore is usually single, painless, and hard, accompanied by swollen lymph nodes. This sore can start as a red spot that later becomes an ulcer and there may be minor bleeding in the soft palate even without the presence of this sore.
The next stage is secondary syphilis, which is highly contagious and tends to develop 2 to 8 weeks after the initial sore appears. In this stage, the person may have skin rashes on the palms and soles, experience hair loss and fever, and have disease spots involving the mouth. Unlike in the first syphilis stage, now the mouth sores are multiple and painful, often appearing as small or shallow oval ulcers with a red border and a grey covering. Sometimes, people report having a sore throat. Prominent sores may also develop on the tongue along with a painless wart-like growth on the genitals.
Tertiary syphilis is a more severe stage, sometimes developing months or years after the initial infection if not appropriately treated beforehand. It can cause severe damage to the oral cavity, such as a chronic growth commonly found on the hard palate, which could erode into the nasal septum. The tongue may present with white lesions or appear slim and fissured. Other serious symptoms associated with this phase include eye abnormalities, inflammation of the aorta due to damage to vasa vasorums, and neurosyphilis, a condition that affects the nervous system.
Syphilis can also be transferred from an infected mother to the child during pregnancy, more commonly after 16 weeks. This is known as congenital syphilis. In babies born with this condition, typical features include changes in the teeth; one notable sign is the appearance of small, widely spaced, and rod-shaped incisors which are semitransparent. Additionally, the molars might be replaced by small dome-shaped teeth with the dental cusps closer together, a condition known as “mulberry molars”.
Gonorrhea, another sexually transmitted infection, can also affect the oral cavity, typically through oral-penile contact. Oral gonorrhea can often present without symptoms. However, if symptoms do develop, commonly reported ones include persistent sore throat, oral ulcers, a red swollen mouth and throat which bleed easily, along with flu-like symptoms. If the disease is untreated, it can spread to other parts of the body and cause fever, chills, skin sores, and inflammation and pain in the joints.
Tuberculosis is a bacterial infection that can also occur in the mouth. The lesions most often appear at the back of the tongue, but can also occur along the insides of the cheeks, gums, lips and the underside of the mouth. During the initial phase, it generally appears as a painful, decaying ulcer that usually lasts for more than two weeks and can spread from the inside lining of the mouth to its base. Secondary tuberculosis causes slow-growing, irregular, and painful oral ulcers that don’t heal on their own and are often found in areas usually exposed to mechanical trauma. Besides these, tuberculosis may also be accompanied by fever, chronic cough, production of sputum, coughing blood, night sweats, loss of weight, and reduced appetite.
Finally, Scarlet Fever which typically co-occurs with a sore throat, can also sometimes present with symptoms in the mouth. Common symptoms include a “sandpaper rash” on the face, trunk, underarms, and groin first, spreading to the limbs later, but sparing the palms and soles. A common oral sign of this disease is the “strawberry tongue”; the tongue looks like a strawberry due to swollen taste buds with a white coating. As the white coating clears, the remaining bumps make the tongue appear red. The throat may also look red and have white or yellow patches, causing pain while swallowing.
Testing for Bacterial Infections of the Oral Mucosa (Oral Infections)
If you have a sore in your mouth that hasn’t healed after two weeks, it’s very important to get a thorough medical check-up. This should involve a good look at your mouth and the areas around it, including the lymph nodes. X-rays may also be needed to check for any issues with your bones.
If your doctor thinks you might have syphilis, they’ll crosscheck using tests like the VDRL (venereal disease research laboratory) test or RPR (rapid plasma regain) test. If these come back positive, more specific tests would need to be done to confirm if you indeed have syphilis. These include the FTA-ABS (fluorescent treponemal antibody absorption) test or TP-MHA (treponema pallidum microhemagglutination assay).
In syphilis, a type of bacteria called spirochetes can sometimes be found in the sores that appear during its early stages. A microscope can be used to look for these, but it can sometimes give false results, especially when examining oral lesions. This is because similar-looking bacteria are naturally found in the mouth. The FTA-ABS test can still be used to check during the later stages of syphilis; even though some tests can give false negatives, the FTA-ABS often remains positive even after successful treatment.
If you’re showing signs and symptoms of syphilis, doctors would test for other STDs as well. Pregnant women should also be screened for syphilis during their first trimester, to prevent it from affecting the baby.
If you have symptoms that suggest you might have gonorrhea, lab tests that take swabs from the genital, rectum or throat areas can help confirm it. The nucleic acid amplification tests (NAATs) are some examples that detect the gonorrhea bacteria, even when found in places like the throat. These tests can also screen for a number of other sexually transmitted diseases at the same time.
If your doctor thinks you may have tuberculosis, they could use a range of tests such as checking a tissue sample, a skin test, staining and observing for acid-fast bacteria. They could also get a sample culture or run a polymerase chain reaction test. If a sore doesn’t get better, you might need a biopsy, which involves taking a small tissue sample to help confirm if it’s tuberculosis or rule out cancer. If the skin test indicates TB, a confirming chest X-ray is required because if you’ve had the TB vaccine, your skin test might come back falsely positive.
Scarlet fever can sometimes be identified through a check-up and your medical history. But because symptoms can vary greatly in the early stages, you might need a throat culture test or rapid strep test. If you test positive for group A strep, treatment would start right away. If it’s negative but scarlet fever is still suspected, a throat culture will be done next. These tests aren’t usually recommended for older patients because they’re less likely to have scarlet fever. Even though it takes longer, a throat culture is more precise and can find bacteria that the rapid strep test might miss. In young patients with a CENTOR score of 2 or more, a throat culture is recommended. This score gives an estimate of how likely it is that a sore throat is caused by strep. It looks at several factors including age, throat inflammation and discharge, swollen lymph nodes, fever and whether or not the patient has a cough.
Treatment Options for Bacterial Infections of the Oral Mucosa (Oral Infections)
In primary stage syphilis, sores and mouth lesions usually heal on their own within three to six weeks, leaving no scar. However, a shot of long-acting benzathine penicillin G may be required if primary symptoms persist, or for treatment of secondary syphilis. For the third, or “tertiary”, stage of syphilis, the same drug is administered once a week for three to four weeks. The length of treatment depends on how far the disease has progressed and the symptoms displayed. People who are allergic to penicillin can be treated with alternatives like doxycycline, tetracycline, or ceftriaxone. Once diagnosed with syphilis, the patient must avoid all sexual activity to prevent spreading the disease, and anyone who had sexual contact with the patient should be informed, tested, and treated if necessary. Follow-up checks using special blood tests are necessary every three months for a year after treatment to make sure it was effective.
To treat oropharyngeal gonorrhea, a single oral dose of 400 mg cefixime could be used. However, due to increasing resistance of the gonorrhea bacterium to cephalosporins, higher doses of ceftriaxone and cefixime may be considered. In Canada, the Public Health Agency recommends a stronger oral cefixime dose or an intramuscular injection of ceftriaxone, with the latter particularly useful for infections in the throat. They also mention that intravenous aztreonam could be used for throat and rectal infections from gonorrhea. Anyone diagnosed with sexually transmitted diseases should see a specialist in genital and urinary medicine.
For tuberculosis, a combintion of several drugs, including isoniazid, rifampin, pyrazinamide, and ethambutol, is typically used. All these drugs are taken daily for the first two months, and then just the first three drugs for another four months. A lung doctor must supervise this treatment to make sure the patient follows the course and to lower the risk of the tuberculosis bacteria becoming resistant to the drugs. Patients should remain in isolation while they’re being treated to prevent spreading the disease. Some second-line treatment options include injectable drugs and fluoroquinolones. The BCG vaccine against TB is widely used in developing countries to help control the spread of the disease.
For Scarlet Fever, beta-lactam antibiotics are the first choice for treatment because they work well and are inexpensive. Comparisons show penicillins work better than cephalosporins and macrolides. If a patient is allergic to penicillin, a first-generation cephalosporin can be very effective. Oral penicillin is generally taken four times a day for ten days to treat the infection, and other symptoms may be managed with acetaminophen or ibuprofen and fluids. The oral symptoms of Scarlet Fever usually resolve themselves within two weeks.
What else can Bacterial Infections of the Oral Mucosa (Oral Infections) be?
- Skin cancer known as squamous cell carcinoma
- Viral infections like herpes or fungal infections
- Sexually transmitted infection called Chlamydia
- A type of fungal lung infection known as Histoplasmosis
- A rare childhood disease that causes inflammation in the blood vessels called Kawasaki disease
What to expect with Bacterial Infections of the Oral Mucosa (Oral Infections)
The outlook for oral lesions, or mouth sores, is generally good if patients seek treatment as soon as they notice them. Without appropriate care, these sores can become frequent, take longer to heal, or potentially worsen into precancerous or cancerous lesions. The mentioned diseases may show signs in the oral cavity either at the beginning or in later stages of the disease.
Dentists and other healthcare professionals must be able to recognize these sores, as early diagnosis and timely treatment can reduce the chances of spreading and further complications. The prognosis, or the likely course of the disease, depends on the stage at which it’s caught – for instance, in the case of syphilis, catching it early significantly lowers the risks and severity of the disease.
Possible Complications When Diagnosed with Bacterial Infections of the Oral Mucosa (Oral Infections)
If syphilis isn’t treated, it can cause irreversible damage to the heart and brain. While treatment can stop the disease from getting worse, it won’t undo any existing damage. In cases of secondary syphilis with high levels of the bacteria, treatment with penicillin can trigger a reaction known as Jarisch-Herxheimer. This reaction, characterized by symptoms including headaches, muscle pain, fatigue, fever, and rapid heart rate, occurs within 24 hours of treatment as the dying bacteria release substances that cause inflammation.
Gonorrhea, if not diagnosed or treated, can lead to severe complications. The infection can spread, causing issues such as pelvic inflammatory disease, inflammation of the uterus lining, ectopic pregnancy (a pregnancy that occurs outside the uterus), and infertility.
People with weak immune systems, such as people living with HIV, may struggle to control tuberculosis bacteria in their bodies. If the bacteria are resistant to drugs of tuberculosis, it can spread throughout the body. Complications can include spinal pain, meningitis (inflammation of the membranes around the brain and spinal cord), and miliary tuberculosis, a severe form of the disease in which tiny nodules spread all over the body.
If scarlet fever isn’t treated, it can lead to rheumatic fever, which can affect the heart, joints, skin, and brain. This condition tends to develop 2 to 3 weeks after the initial scarlet fever infection and is most common in children. Untreated scarlet fever can also lead to kidney complications, such as post-streptococcal glomerulonephritis, a condition that can develop a few weeks after a throat infection or 3 to 6 weeks after a skin infection caused by the same bacteria that cause scarlet fever. This kidney condition is also more common in children than adults.
