Dermatology · Oral Mucosal Disorders

Aphthous Ulcers (Canker Sores)

USMLE2PANCE
7

Bets

The facts most likely to be tested

1

Aphthous ulcers present as painful, round or oval ulcers with a yellow-gray fibrinous center and an erythematous halo on non-keratinized oral mucosa.

Confidence:
2

The diagnosis of recurrent aphthous stomatitis is primarily clinical, based on the history of recurrent episodes and the characteristic appearance of the lesions.

Confidence:
3

First-line treatment for symptomatic relief involves topical corticosteroids, such as triamcinolone dental paste or fluocinonide gel.

Confidence:
4

Aphthous ulcers are non-contagious, which distinguishes them from herpetic gingivostomatitis that typically presents with vesicles on keratinized mucosa.

Confidence:
5

Recurrent, severe, or refractory aphthous ulcers necessitate screening for underlying systemic conditions, most notably Behçet syndrome, celiac disease, and inflammatory bowel disease.

Confidence:
6

Behçet syndrome is characterized by the triad of recurrent oral aphthous ulcers, genital ulcers, and uveitis.

Confidence:
7

Patients with frequent outbreaks should be evaluated for nutritional deficiencies, specifically iron, folate, vitamin B12, or zinc.

Confidence:

Vignette unlocked

A 24-year-old female presents to the clinic complaining of recurrent mouth pain. She reports that she develops painful, shallow ulcers on the inside of her cheeks approximately once a month that last for 7 to 10 days. Physical examination reveals a 0.5 cm round ulcer with a yellow-gray center surrounded by an erythematous halo on the buccal mucosa. The patient has no history of fever, lymphadenopathy, or genital lesions. She is otherwise healthy and takes no medications.

What is the most appropriate initial management for this patient's condition?

+Reveal answer

Topical corticosteroids

The patient's presentation is classic for minor aphthous ulcers, which are managed symptomatically with topical corticosteroids to reduce inflammation and pain.

Mo

Depth

Full handout

High yield triage

Etiology / Epidemiology

Common in young adults and females; triggered by stress, trauma, or nutritional deficiencies (B12, folate, iron).

Clinical Manifestations

Painful, round/oval ulcers with erythematous halos on non-keratinized mucosa (buccal/labial).

Diagnosis

Diagnosis is clinical; no lab testing required unless recurrent to rule out Behçet syndrome.

Treatment

Topical corticosteroids (e.g., fluocinonide) are first-line; avoid systemic steroids for simple cases.

Prognosis

Self-limiting; 1-2 weeks for resolution. Recurrence is common.

Full handout

Epidemiology & Etiology

Affects 20% of the population, with peak incidence in the second decade of life. Triggers include local trauma, emotional stress, and food sensitivities. Consider underlying celiac disease or IBD in patients with frequent, severe outbreaks.

Pertinent Anatomy

Strictly limited to non-keratinized mucosa (buccal mucosa, floor of mouth, soft palate). Lesions do not involve the attached gingiva or hard palate, which helps distinguish them from herpetic gingivostomatitis.

Pathophysiology

A T-cell mediated immune response leads to localized destruction of the oral epithelium. The process involves cytokine-mediated ulceration triggered by minor mucosal injury. Genetic predisposition is noted in 40% of patients with a positive family history.

Clinical Manifestations

Presents as a shallow, painful ulcer with a yellow-gray fibrinous center and a halo of erythema. Red flags include ulcers lasting >3 weeks, systemic symptoms, or genital involvement, which suggest Behçet syndrome or malignancy.

Diagnosis

Diagnosis is clinical based on history and physical exam. No gold standard biopsy is required for typical cases. If ulcers are persistent or atypical, order a CBC, ferritin, B12, and folate to rule out systemic deficiencies.

Treatment

First-line therapy is topical corticosteroids (e.g., fluocinonide gel or dexamethasone elixir). Use topical anesthetics (lidocaine) for pain control. Avoid systemic steroids due to side effect profile. Refractory cases may require referral for cimetidine or colchicine.

Prognosis

Most lesions heal spontaneously within 7-14 days without scarring. Recurrence is the hallmark of the condition, often requiring lifestyle modification or stress reduction.

Differential Diagnosis

Herpes Simplex: vesicles precede ulcers; involves keratinized mucosa

Behçet Syndrome: triad of oral ulcers, genital ulcers, and uveitis

Hand-Foot-Mouth Disease: associated with rash on palms and soles

Squamous Cell Carcinoma: indurated, non-healing ulcer >3 weeks

Erythema Multiforme: target-like lesions and crusting of lips