How long can an aphthous ulcer last?

Duration of Aphthous Ulcers

Minor aphthous ulcers typically heal in 10-14 days without scarring, while major aphthous ulcers can persist for 10 days to 6 weeks or longer and frequently leave scars. 1, 2, 3

Duration by Clinical Type

The healing time of aphthous ulcers depends critically on their classification:

Minor Aphthous Ulcers (Most Common)

• Heal within 10-14 days without scarring 3
• Represent the most common presentation of recurrent aphthous stomatitis 3
• Are characterized as small, round, clearly defined painful ulcers 3

Major Aphthous Ulcers

• Take 10-30 days to heal, but can persist for 6 weeks or longer 2, 3
• Are greater than 10 mm in diameter 2
• Frequently leave scars after healing 2, 3
• Constitute 10-15% of recurrent aphthous ulcers 2
• May persist for several weeks to months when refractory 4

Herpetiform Aphthous Ulcers

• Last 7-10 days 3
• Present as multiple small clusters of pinpoint lesions that can coalesce 3

When to Investigate Further

For any aphthous ulcer persisting beyond 2 weeks or not responding to treatment, further investigation is mandatory. 1

First-Line Testing

• Full blood count 1
• Fasting blood glucose 1
• HIV antibody testing 1
• Syphilis serology 1

Second-Line Testing

• Nutritional deficiency screening (iron, folate, vitamin B12) 1
• Autoimmune markers if autoimmune conditions are suspected 1

Biopsy Indications

• Any ulcer persisting beyond 2 weeks requires biopsy to rule out malignancy 1, 5
• Every oral solitary chronic ulcer should be biopsied to exclude squamous cell carcinoma 5

Clinical Pitfalls to Avoid

• Do not rely solely on clinical appearance for persistent ulcers without appropriate diagnostic testing 1
• Do not overlook systemic causes including celiac disease, inflammatory bowel diseases, nutritional deficiencies, immune disorders, and Behçet's disease 5
• Do not treat symptoms without establishing a definitive diagnosis for ulcers lasting beyond 2 weeks 1

Exceptional Cases

In documented case reports, major aphthous ulcers have persisted for extraordinary durations:

• One case documented a major aphthous ulcer persisting for 10 months despite topical medications 4
• Another case reported ulcers lasting 2-3 months before diagnosis and treatment 2

These exceptional cases underscore the importance of early systemic intervention for major aphthous ulcers that do not follow the typical healing timeline.