What is Ulcus (Mouth Sores)?
Ulcus, commonly called a mouth sore, is a painful, shallow lesion that develops on the soft tissues inside the mouthâmost often on the inner cheeks, tongue, gums, or the floor of the mouth. These ulcers are usually round or oval, have a white or yellowish center surrounded by a red halo, and may range from a few millimeters to several centimeters in size. While most mouth sores are harmless and resolve on their own within 1â2 weeks, they can sometimes signal an underlying medical condition or infection that requires attention.
Common Causes
Below are the most frequent reasons why an ulcer appears in the oral cavity.
- Aphthous stomatitis (canker sores) â small, recurring ulcers of unknown exact cause, often triggered by stress or minor oral trauma.
- Trauma â accidental bites, sharp edges of dental appliances, aggressive brushing, or illâfitting dentures.
- Viral infections â herpes simplex virus (cold sores), coxsackievirus (handâfootâmouth disease), or varicellaâzoster.
- Bacterial infections â Treponema pallidum (syphilis) or Mycobacterium species (tuberculosis oral lesions).
- Fungal infection â oral thrush caused by Candida albicans.
- Autoimmune diseases â Behçetâs disease, lupus, or pemphigus vulgaris may produce persistent ulcers.
- Nutritional deficiencies â low iron, folate, vitamin Bâ12, or vitamin C.
- Medication side effects â chemotherapy, nonâsteroidal antiâinflammatory drugs (NSAIDs), or some antihypertensives.
- Allergic reactions â contact allergy to toothpaste, mouthwash, or certain foods.
- Systemic illnesses â inflammatory bowel disease (Crohnâs disease, ulcerative colitis), HIV/AIDS, or diabetes mellitus.
Associated Symptoms
Mouth ulcers rarely occur in isolation. The following signs often accompany them, helping clinicians narrow down the cause.
- Burning or tingling sensation before the sore appears.
- Difficulty eating, drinking, or speaking due to pain.
- Fever, chills, or malaise (more common with viral or bacterial infection).
- Swollen lymph nodes in the neck or under the jaw.
- Multiple sores that appear simultaneously (suggests aphthous stomatitis or systemic disease).
- White curdâlike coating on the tongue or palate (indicative of candidiasis).
- Skin lesions elsewhere on the body (e.g., erythema nodosum in Behçetâs disease).
- Joint pain or gastrointestinal symptoms (pointing toward inflammatory bowel disease).
When to See a Doctor
Most mouth sores improve without medical care, but you should schedule an appointment if any of the following occur:
- The ulcer lasts longer than 3 weeks.
- Severe pain that interferes with nutrition or hydration.
- Repeated episodes (more than 3â4 times a year) without a clear trigger.
- Ulcers are larger than 1âŻcm, have an irregular border, or are accompanied by a lump.
- Unexplained weight loss, persistent fever, night sweats, or swollen lymph nodes.
- Signs of infection such as pus, increasing redness, or a foul odor.
- History of cancer, immunosuppression, or recent chemotherapy/radiation therapy.
Diagnosis
Healthcare providers use a combination of history taking, visual examination, and, when needed, laboratory or imaging studies.
Stepâbyâstep evaluation
- Medical history â questions about diet, stress, medication use, recent illnesses, and systemic diseases.
- Oral examination â inspection with a tongue depressor and light source; measurement of size, number, and location of ulcers.
- Swab or biopsy â if the lesion looks suspicious (irregular border, persistent beyond 3 weeks) a tissue sample may be sent for pathology.
- Blood tests â CBC, iron studies, vitamin Bâ12, folate levels, HIV screening, or autoimmune panels when indicated.
- Viral cultures or PCR â for suspected herpes simplex or Coxsackie virus.
- Imaging â rarely needed, but a panoramic Xâray or CT scan can rule out underlying bone infection (osteomyelitis) or malignancy.
Treatment Options
Management is tailored to the underlying cause and severity of symptoms.
Selfâcare and home remedies
- Saltâwater rinse â dissolve ½âŻtsp of salt in 8âŻoz warm water; rinse 3â4 times daily to reduce inflammation.
- Topical anesthetics â overâtheâcounter benzocaine or lidocaine gels provide temporary pain relief.
- Honey â raw or medicalâgrade honey has antimicrobial properties and can be applied gently to the ulcer.
- Avoid irritants â steer clear of spicy, acidic, or crunchy foods; use a softâbristled toothbrush.
- Hydration â sip water or nonâcitrus electrolyte drinks to keep the mouth moist.
Pharmacologic therapies
- Topical corticosteroids â clobetasol or fluocinonide paste applied 2â3âŻtimes daily for painful aphthous ulcers (prescription required).
- Systemic corticosteroids â short courses of prednisone for severe or extensive ulcers, especially when linked to autoimmune disease.
- Antiviral medication â acyclovir, valacyclovir, or famciclovir for herpes simplexârelated lesions.
- Antifungal agents â nystatin suspension or fluconazole for candidal ulcers.
- Antibiotics â amoxicillinâclavulanate or clindamycin if a bacterial infection is confirmed.
- Immunomodulators â colchicine, thalidomide, or biologics (e.g., infliximab) for refractory aphthous ulcers associated with Behçetâs disease.
- Vitamin supplementation â oral iron, folic acid, vitamin Bâ12, or vitamin C when labs show deficiency.
Procedural options
- Laser therapy â lowâlevel laser can accelerate healing and reduce pain.
- Electrocoagulation â cauterizes larger ulcers that bleed or recur frequently.
- Excisional biopsy â performed when malignancy cannot be ruled out.
Prevention Tips
While not all mouth sores can be avoided, the following strategies lower the likelihood of recurrence.
- Maintain excellent oral hygiene but use a softâbristled brush and nonâalcoholic toothpaste.
- Identify and eliminate trigger foods (citrus, nuts, very hot beverages).
- Manage stress through relaxation techniques, regular exercise, or counseling.
- Stay wellânutrientâreplete: eat a balanced diet rich in leafy greens, lean protein, and whole grains.
- Quit smoking and limit alcohol intake, both of which irritate oral mucosa.
- Regular dental checkâups (at least twice a year) to adjust illâfitting prostheses.
- For those with chronic conditions (e.g., IBD), adhere to prescribed diseaseâmodifying therapy.
- Use protective mouth guards during contact sports to prevent traumatic ulcers.
Emergency Warning Signs
Seek immediate medical attention if you notice any of the following:
- Rapid spreading of the ulcer or multiple lesions appearing within 24âŻhours.
- Severe, unrelenting pain that does not improve with overâtheâcounter analgesics.
- Signs of a serious infection: feverâŻ>âŻ101âŻÂ°F (38.3âŻÂ°C), chills, swelling that worsens, or pus discharge.
- Difficulty breathing or swallowing (possible airway compromise).
- Bleeding that does not stop after applying pressure for 10âŻminutes.
- Visible lump or hard area under the ulcer, weight loss, night sweats, or persistent fatigue.
- Any ulcer that does not heal within 3âŻweeks despite home care.
References
- Mayo Clinic. âCanker sores.â https://www.mayoclinic.org
- Cleveland Clinic. âOral Ulcers: Causes, Diagnosis, and Treatment.â https://my.clevelandclinic.org
- National Institutes of Health (NIH). âAphthous Stomatitis.â https://www.ncbi.nlm.nih.gov
- World Health Organization. âOral health.â https://www.who.int
- Centers for Disease Control and Prevention. âHerpes Simplex Virus.â https://www.cdc.gov
- Journal of Oral Pathology & Medicine. âManagement of oral ulcerations.â 2022; 51(4): 317â328.