Oral Medicine · Specialist Guide
Recurrent Mouth Ulcers (Aphthous Stomatitis) — Causes & Treatment
Recurrent aphthous stomatitis is the most common ulcerative condition of the mouth — round, painful, yellow-based ulcers that heal in 7–14 days and come back. Most cases are idiopathic, but a meaningful minority hide systemic causes (iron / B12 / folate deficiency, coeliac disease, Crohn's, Behcet's). Treatment combines local symptom control with a workup for systemic triggers when ulcers are frequent or severe.
Medically reviewed by
Dr. Bipin R. Upadhyay
BDS · MDS Oral Medicine & Radiology · PhD Scholar · Associate Professor & Head, Department of Dentistry
Last clinically reviewed: 2026-06-10
- Types
- Minor (<10 mm), major (>10 mm, scarring), herpetiform (multiple pinpoint)
- Usual sites
- Non-keratinised mucosa: lip, cheek, floor of mouth, ventral tongue
- Average healing
- Minor 7–14 days, major up to 6 weeks
- Systemic causes to rule out
- Iron/B12/folate deficiency, coeliac, Crohn's, Behcet's, HIV
- First-line treatment
- Topical steroid + chlorhexidine + trigger avoidance
Symptoms to watch for
Causes & risk factors
- Idiopathic — most cases
- Iron, B12 or folate deficiency
- Stress and sleep deprivation
- Local trauma (sharp tooth, biting)
- Sodium lauryl sulfate (SLS) in toothpaste
- Food sensitivity (chocolate, citrus, tomatoes, nuts in some)
- Coeliac disease, Crohn's disease, Behcet's disease
The three clinical types
Minor aphthae (<10 mm, heal in 7–14 days, no scarring) account for ~80% of cases. Major aphthae (>10 mm, deep, take up to 6 weeks, scar) are far more painful and more often associated with systemic disease. Herpetiform aphthae (1–3 mm pinpoint ulcers in crops) are easily mistaken for herpes but are not infectious.
When ulcers need a systemic workup
Order full blood count, ferritin, B12, folate, anti-tTG (coeliac) for any patient with frequent (more than once a month), severe, or major aphthae. Add HIV and Behcet's workup when clinically appropriate.
Treatment
Local control reduces pain and shortens episodes; systemic control prevents recurrence when a cause is found.
- Topical corticosteroid pastes (triamcinolone, clobetasol)
- Chlorhexidine 0.2% mouthrinse 2× daily for 1 week
- Topical anaesthetic gels for pain
- SLS-free toothpaste for selected patients
- Iron / B12 / folate replacement when deficient
- Colchicine, pentoxifylline, dapsone or systemic steroids for severe RAS
Trigger detection — what actually works
A 4-week food and lifestyle diary identifies personal triggers in many patients. The reproducible offenders are SLS toothpaste, citrus, tomato, chocolate, nuts, gluten in coeliac patients, sleep deprivation and trauma from sharp restorations. Empirical avoidance of common offenders rarely works without tracking.
When an 'ulcer' is not an ulcer
Any single ulcer lasting beyond 3 weeks, especially in a tobacco or areca-nut user, is treated as suspected malignancy until biopsy proves otherwise. Aphthae do not last 3 weeks.
See a specialist if you have any of these
- A single ulcer lasting >3 weeks (think malignancy, not aphthae)
- Ulcers with associated genital ulcers or eye inflammation (Behcet's)
- Ulcers with chronic diarrhoea, anaemia or weight loss
- Ulcers in a known immunocompromised patient
Frequently asked questions
Are mouth ulcers and cold sores the same thing?
No. Aphthous ulcers occur on the soft, non-keratinised mucosa inside the mouth and are not infectious. Cold sores (herpes labialis) occur on the lip and keratinised mucosa, are caused by HSV-1, and are infectious.
How long should a mouth ulcer take to heal?
Minor aphthae heal within 7–14 days. Any single ulcer that persists beyond 3 weeks needs specialist evaluation and possibly a biopsy.
Will vitamins cure my ulcers?
Only if you are deficient. Empirical vitamins without testing are usually a waste of money. A simple blood panel tells you whether you actually need replacement.
Can stress alone cause mouth ulcers?
Yes — stress and sleep deprivation are very common triggers. But a patient with monthly ulcers still deserves a basic blood workup.
Are ulcers in children always aphthae?
Most are, but recurrent ulcers in children should be screened for coeliac disease, iron and B12 deficiency, and PFAPA syndrome (periodic fever with aphthae).
Is SLS toothpaste really a trigger?
In a subset of patients, yes. A 6-week trial of an SLS-free paste is a low-cost, evidence-supported step.
Where can I get recurrent mouth ulcers evaluated in Mumbai?
Dr. Bipin R. Upadhyay manages recurrent and severe aphthous ulcers, including major and herpetiform forms, at K.J. Somaiya Super Speciality Hospital, Sion (Mumbai) and at Reasonable Smile Dental Clinics, Ambarnath.
Specialist care for Recurrent Aphthous Stomatitis in Mumbai & Ambarnath
Dr. Upadhyay reviews recurrent aphthous stomatitis at K.J. Somaiya Super Speciality Hospital, Sion (Mumbai) and Reasonable Smile Dental Clinics, Ambarnath. Patients from outside the MMR are seen first by teleconsultation.
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