Ulcers and Lesions

💡Traumatic Ulcers

Causes

• Mechanical trauma: sharp teeth, broken restorations, dental appliances.
• Chemical trauma: aspirin burns.
• Thermal injury.
• Self-inflicted trauma, e.g., morsicatio buccarum (cheek biting).

Clinical features

• Usually a single ulcer at the site of trauma.
• Painful, with irregular margins and a yellowish-white fibrinous base.

Healing

• Usually heals within 7–14 days after removal of the cause.
• An ulcer persisting for more than 3 weeks requires biopsy to exclude squamous cell carcinoma (SCC).

💡Recurrent Aphthous Stomatitis (RAS)

Definition: The most common inflammatory ulcerative condition of the oral mucosa, affecting approximately 20–25% of the population.

Etiology and predisposing factors

• Genetic predisposition — family history in approximately 40%.
• Hematological deficiencies: iron, vitamin B12, and folate.
• Stress and hormonal changes.
• Food sensitivity.
• Sodium lauryl sulfate (SLS) in toothpaste may contribute.

Important: RAS is not caused by herpes simplex virus (HSV).

Sites: Non-keratinized mucosa, including buccal mucosa, labial mucosa, floor of mouth, and ventral tongue.

Types of RAS

Differential diagnosis: RAS vs primary herpetic gingivostomatitis

Investigations

• CBC.
• Serum ferritin and iron studies.
• Vitamin B12 and folate.
• Celiac disease screening: anti-tTG and EMA.
• HLA-B51 testing when Behçet disease is suspected.

Treatment

Local treatment

• Topical corticosteroids are first-line: triamcinolone 0.1% in Orabase, 3–4 times daily.
• Chlorhexidine 0.2% mouthwash.
• Benzydamine for analgesia.

Systemic treatment for severe disease

• Colchicine.
• Dapsone.
• Thalidomide — teratogenic.
• Short courses of prednisolone.
• Azathioprine in selected cases.

• Minor RAS is the commonest form.
• Herpetiform RAS consists of numerous tiny ulcers but has no preceding vesicles and is not contagious.
• Major aphthae may heal with scarring.
• Investigate iron, B12, folate, and celiac disease in recurrent or severe cases.

💡Behçet Disease

Definition: A chronic, relapsing, multisystem vasculitis.

Classic triad

1. Recurrent oral ulcers.
2. Genital ulcers.
3. Ocular inflammation, particularly uveitis, which can lead to blindness.

Other manifestations

• Skin: Erythema nodosum, papulopustular lesions.
• Joints: Arthritis.
• CNS: Neuro-Behçet disease.
• Vascular: Venous thrombosis and arterial aneurysms.
• Gastrointestinal: GI ulceration.

Pathergy test

• A pustule develops at a needle-prick site within approximately 24–48 hours.
• Positive in around 50% of patients according to the notes.

Association

• HLA-B51.

Diagnosis

Consider Behçet disease in a patient with recurrent oral ulcers plus genital ulcers, ocular disease, skin manifestations, or a positive pathergy test.

Treatment

• Corticosteroids.
• Colchicine.
• Azathioprine.
• Cyclosporine.
• Anti-TNF agents, e.g., infliximab and adalimumab.

💡Vesiculobulous Diseases

💡Pemphigus Vulgaris

Definition: An autoimmune intraepithelial blistering disease caused by antibodies against desmosomal proteins.

Pathogenesis

• Anti-desmoglein 3 antibodies → predominantly mucosal disease.
• Anti-desmoglein 1 antibodies → cutaneous involvement.
• Both antibodies may be present in mucocutaneous disease.

Clinical features

• Oral lesions are the initial manifestation in approximately 60% of cases.
• Oral disease may precede skin lesions by months.
• Flaccid bullae rupture easily, producing persistent, irregular, painful erosions.

Clinical signs

• Nikolsky sign: Positive — lateral pressure on apparently normal skin or mucosa may cause epithelial separation.
• Asboe-Hansen sign: Pressure on an intact blister causes it to extend into surrounding tissue.

Histopathology

• Suprabasal acantholysis.
• Basal cells remain attached to the basement membrane, producing a “row of tombstones” appearance.
• Tzanck cells may be present.

Investigations

• Direct immunofluorescence (DIF): Intercellular IgG and C3 in a chicken-wire or fish-net pattern.
• Indirect immunofluorescence (IIF): Circulating antibodies against epithelial antigens.
• Anti-desmoglein antibody titers may correlate with disease activity.

Treatment

• High-dose systemic corticosteroids, e.g., prednisolone approximately 1–2 mg/kg/day in severe disease.
• Steroid-sparing immunosuppressants: azathioprine or mycophenolate.
• Rituximab.

Prognosis: Potentially fatal if untreated.

💡Mucous Membrane Pemphigoid (MMP)

Definition: An autoimmune subepithelial blistering disease that predominantly affects mucous membranes.

Target antigens

• BP180.
• Laminin 332.

Clinical features

• Tense bullae because the split occurs beneath the epithelium.
• Desquamative gingivitis is a common oral presentation.
• Nikolsky sign is usually negative or weakly positive.

Ocular involvement

• Conjunctival scarring.
• Symblepharon formation (adhesion between conjunctival surfaces).
• Progressive scarring may cause blindness.

Important: Ocular involvement requires ophthalmological assessment.

Investigations

• DIF: Linear IgG and/or C3 deposition along the basement membrane zone.
• Salt-split skin: Antibody binding on the dermal (floor) side may occur, depending on the target antigen.

Treatment

• Topical clobetasol for localized oral disease.
• Dapsone.
• Systemic immunosuppressants for severe disease.
• Ophthalmological co-management for ocular involvement.

Pemphigus vulgaris vs mucous membrane pemphigoid

Memory aid

• Pemphigus: Intraepithelial, flaccid bullae, positive Nikolsky, chicken-wire DIF.
• Pemphigoid: Subepithelial, tense bullae, linear DIF, scarring.

💡Erythema Multiforme (EM)

Etiology

• HSV is the leading trigger of recurrent erythema multiforme, accounting for approximately 90% of recurrent cases in the notes.
• Medications may also trigger EM, particularly sulfonamides and NSAIDs.

Clinical features

• Acute onset.
• Target or iris lesions, classically involving the skin.
• Oral hemorrhagic lip crusting.
• Diffuse oral erosions.

Classification

Treatment

• Supportive care.
• Topical corticosteroids for oral inflammation.
• Acyclovir prophylaxis for recurrent HSV-associated disease: the notes list 400 mg twice daily for 6–12 months.

Exam pearl: HSV-associated recurrent EM classically presents with target lesions and hemorrhagic crusting of the lips.

💡Other Conditions

💡Linear IgA Disease

• Rare autoimmune subepithelial blistering disorder.
• DIF: Linear IgA deposition along the basement membrane zone.
• Classic drug trigger: Vancomycin.
• Treatment: Dapsone.

💡Allergic/Contact Stomatitis

Mechanism: Type IV delayed hypersensitivity reaction.

Common allergens

• Dental materials: nickel, mercury, acrylic.
• Flavouring agents, particularly cinnamon.

Diagnosis

• Patch testing, with readings at 48–72 hours.

Treatment

• Identify and eliminate the offending allergen.

💡Quick-Recall Table

Essential biopsy rule

Any oral ulcer that fails to heal after 3 weeks requires biopsy to exclude malignancy, particularly SCC.