A 5-year-old girl is in her pediatrician’s office for her school physical and immunizations when her mother asks about her child’s complaint of mouth pain. The girl is otherwise healthy and on physical examination a small round ulcer is seen on the nonkeratinized mucosa above the upper teeth (Figure 40-1). The necrotic center with slightly raised borders and surrounding erythema were easily recognized features of an aphthous ulcer. The pediatrician reassured the mother that this will go away spontaneously without medication or treatment. She suggested to avoid giving the child acidic or spicy foods in the coming days and to be careful to not traumatize the ulcer further with vigorous toothbrushing.

Aphthous ulcers are painful ulcerations in the mouth, which can be single, multiple, occasional, or recurrent. These ulcers can be small or large but are uniformly painful and may interfere with eating, speaking, and swallowing. Oral trauma, stress, and systemic diseases can contribute to the occurrence of these ulcers but no precise etiology is apparent. Recurrent aphthous stomatitis (RAS) is a frustrating condition that merits aggressive treatment aimed at pain relief and prevention.

Canker sores, aphthous stomatitis, aphthae, recurrent aphthous ulcer (RAU), or recurrent aphthous stomatitis (RAS).

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  Twenty percent of the general population are reported to have aphthous ulcers.¹

  
  
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  One and 1/2 percent of children and adolescents have been reported to have RAUs.²

  
  
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  RAS is more common in females, in people younger than age 40 years, in whites, in nonsmokers, and in people of high socioeconomic status.²

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  The precise etiology and pathogenesis of this condition remains unknown, although a variety of host and environmental factors have been implicated.

  
  
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  A positive family history is seen in about 1/3 of RAS patients. A genetic predisposition is suggested by an increased frequency of HLA types A2, A11, B12, and DR2.²

  
  
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  In one study, Th1 (T-helper subtype 1) activation was more intense in the patients with RAUs. Many conditions that increase the incidence of RAUs, such as psychologic stress, NSAIDs, Crohn disease, and celiac disease, also shift the immune response toward the Th1 subtype. Conditions and medications that inhibit the Th1 immune response pathway, such as pregnancy, thalidomide, glucocorticoids, and tetracycline, decrease the incidence of RAUs.³

  
  
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  Another study found a significantly higher-than-normal serum level of tumor necrosis factor (TNF)-a in 20 to 39 percent of patients in the ulcerative stage of RAUs.³ Medications that have anti–TNF-a effects, such as pentoxifylline, levamisole, and thalidomide, have also been found to be useful in the treatment of RAUs.^2–4

  
  
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  Although studies show that there are active immune mechanisms associated with RAUs, there is still much to learn regarding their etiology and pathogenesis.

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  Oral trauma.

  
  
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  Stress and anxiety.

  
  
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  Systemic diseases (celiac disease, Crohn disease, Behçet syndrome, HIV, or reactive arthritis).

  
  
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  Medications (NSAIDs, b-blockers, or angiotensin-converting enzyme inhibitors [ACEIs]).

  
  
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  Vitamin deficiencies (zinc, iron, B₁₂, or folate).

  
  
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  Food and chemical sensitivities.

Clinical Features

History:

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  Symptoms may begin with a burning sensation and the pain is exacerbated by moving the area affected by the ulcer.

  
  
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  Eating often hurts, especially foods and drinks with a high acidic content.

  
  
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  Ask about recurrences and onset in relation to the use of medications.

  
  
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  Ask about GI symptoms, genital ulcers, HIV risk factors, and joint pain.

Physical:

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  Three clinical variations are described based on the size of the ulcers:

  
  
  
  
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     Minor (3 to 10 mm) (Figure 40-1)—most common.

     
     
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     Major (>10 mm) (Figure 40-2).

     
     
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     Herpetiform (<3 mm and multiple ulcers) —least common.

  
  
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  The most common minor form appears as rounded, well-demarcated, single, or multiple ulcers less than 1 cm in diameter that usually heal in 10 to 14 days without scarring.

  
  
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  Herpetiform aphthae usually do not present until the second or third decade of life.¹

  
  
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  The ulcers are solitary or multiple covered by a gray or tan pseudomembrane and surrounded by an erythematous halo (Figure 40-1).