What causes ulcers on the soft palate of the throat?

Causes of Soft Palate Ulcers

Soft palate ulcers result from traumatic, infectious, autoimmune, or neoplastic causes, with the specific etiology determined by clinical presentation, duration, and associated systemic features.

Primary Etiologic Categories

Ulcers on the soft palate arise from multiple distinct mechanisms that require systematic evaluation to identify the underlying cause. 1

Traumatic Causes

• Mechanical trauma from sharp food, dental appliances, or iatrogenic injury creates ulcers whose location and shape correspond to the inciting factor 1
• Thermal burns from hot foods or beverages commonly affect the palate 1
• Chemical injury from strong acids, alkalis, or caustic substances 1

Infectious Causes

• Viral infections, particularly herpes simplex virus, typically present with multiple small ulcers and may have vesicles preceding ulceration 2, 3
• Bacterial infections including acute necrotizing ulcerative gingivitis cause rapid-onset ulceration 2, 4
• Tuberculosis produces stellate ulcers with undermined edges and clear boundaries 1
• Deep fungal infections, especially in patients with hyperglycemia or immunosuppression 1, 5
• Syphilis can manifest as palatal ulceration requiring serology testing 1, 5

Autoimmune and Immunologic Causes

• Recurrent aphthous ulcers (RAU) appear as well-demarcated, oval or round ulcers with white/yellow pseudomembrane and surrounding erythematous halo, potentially linked to immune dysregulation, genetic factors, nutrient deficiency, or stress 1
• Pemphigus vulgaris and mucous membrane pemphigoid require evaluation for serum antibodies (Dsg1, Dsg3, BP180, BP230) 1, 5
• Erosive lichen planus presents with chronic multiple ulcers associated with immune disturbances 2
• Behçet's syndrome characterized by recurrent bipolar aphthosis 5, 4
• Erythema multiforme causes acute-onset multiple ulcers 2, 4

Systemic Disease Associations

• Inflammatory bowel disease (Crohn's disease, ulcerative colitis) can manifest with oral ulcers 1, 5
• Blood disorders including anemia, leukemia, and neutropenia may present with widespread necrotic ulcers with yellowish-white pseudomembrane 5
• HIV infection requires antibody testing in persistent cases 1, 5
• Nutritional deficiencies (iron, folate, vitamin B12) contribute to ulceration 1, 5

Neoplastic Causes

• Squamous cell carcinoma typically presents as a solitary chronic ulcer and must be excluded via biopsy in any ulcer persisting beyond 2 weeks 2, 4
• Lymphoma or other hematologic malignancies can present as persistent ulcers 6

Drug-Induced and Allergic Causes

• Medication reactions can cause chronic oral ulcers 4
• Allergic reactions may produce rapid-onset ulceration 1, 2

Specific Palatal Considerations

• Necrotizing sialometaplasia presents as a solitary palatal ulcer and is a specific differential for this location 4

Diagnostic Algorithm for Persistent Soft Palate Ulcers

Initial Assessment

• Document ulcer characteristics: size, number, location, depth, presence of white/yellow pseudomembrane, and surrounding erythema 7
• Determine duration and response to any prior treatment 1
• Identify corresponding traumatic factors if present 1

When to Escalate Evaluation

For ulcers persisting beyond 2 weeks or not responding to 1-2 weeks of treatment, proceed with comprehensive workup including blood tests and consider biopsy. 1, 7, 5

Required Blood Tests Before Biopsy

• Full blood count to detect anemia, leukemia, or other blood disorders 1, 5
• Coagulation studies and fasting blood glucose to exclude biopsy contraindications 1
• HIV antibody and syphilis serology 1, 5
• Serum antibodies (Dsg1, Dsg3, BP180, BP230) if bullous disease suspected 1, 5

Biopsy Indications

• Any solitary chronic ulcer to rule out squamous cell carcinoma 4
• Ulcers with atypical features or unclear etiology 1
• Multiple biopsies if ulcers involve different sites with varying characteristics 5
• Direct immunofluorescence for suspected autoimmune conditions 1, 6

Critical Pitfalls to Avoid

• Never rely solely on topical treatments for persistent ulcers without establishing definitive diagnosis, as this delays identification of malignancy or systemic disease 5, 6
• Inadequate biopsy technique (too small or superficial) misses diagnostic features 5, 6
• Overlooking systemic causes leads to delayed diagnosis and inappropriate management 5, 6
• Failing to biopsy chronic solitary ulcers risks missing squamous cell carcinoma 4

Specialist Referral Criteria

Refer to oral medicine specialist for ulcers lasting more than 2 weeks, those not responding to 1-2 weeks of treatment, or cases with recurrent, severe, or atypical presentations. 7, 6 Oral medicine specialists coordinate multidisciplinary care with gastroenterology for inflammatory bowel disease or hematology for blood disorders as needed 6