What Causes Leucoplakia?

Patient Presentation
A 6-year-old male came to the dentist because of a swollen lip and a white lesion. He had a filling and metal crown placed the morning before and 8 hours later began to develop swelling of his lower right lip that progressed over 1.5 hours. Initially it was just swollen but then began developing the white lesion. He did not have any pain, difficulty breathing, or obvious trauma to the area. He had been well throughout the day after the dental procedure, and had eaten his normal food and denied biting his lip. His mother called the dentist that evening who was not sure what the problem was but was comfortable watching it over the night as he seemed otherwise well. In the morning he went to the dentist for re-evaluation. He was not taking any medications and had received the same local anesthetic he had previously received without problems.

The past medical history was negative.

The family history was negative for any allergies to foods, drugs, and metals.

The review of systems was negative for any difficulties breathing, other areas of swelling, fever, rhinitis, sore throat, rashes, or halitosis.

The pertinent physical exam showed a well-appearing male in no distress. His vital signs were normal as were his growth parameters. His right lower lip was swollen from just inside the corner of the mouth to approximately 1/3 of the lip. On the buccal mucosa was a 0.5 cm flat uniformly white lesion that was non-painful and was not actually ulcerated. There was slight erythema around the edge of the lesion but no evidence of trauma. There was a small spot at the angle of mandible where the local anesthetic had been previously given. All the soft tissues including around the new crown were normal.

The dentist consulted an oral pathologist who felt that the history and physical examination were consistent with the diagnosis of idiopathic localized angioedema. The pathologist said that this was more common in adults but did occasionally occur in children. The mother was instructed to give him diphenhydramine and monitor him for signs of respiratory distress or rashes and was told that this would slowly improve.

The patient’s clinical course showed that he slowly improved and had complete resolution by 6 days.

Case Image
Figure 73 – Clinical image showing the flat, white, non-ulcerated lesion on the buccal mucosa.

Angioedema is edema that is non-pitting and self-limited. It occurs in non-dependent areas usually in an asymmetric distribution usually on the lips, face, hands, feet, genitals and also in the bowel (causing acute abdominal pain). It usually develops over minutes to hours (often 1-2 hours) with resolution usually within 24-48 hours. Angioedema often occurs with urticaria but 20% of patients may have angioedema as an isolated finding. Pain, warmth and erythema also may occur with the affected area. Intraoral lesions are often white (i.e. leucoplakic).

Angioedema is similar to urticaria but affects the deeper dermis and subcutaneous tissues. Triggers cause the degranulation of mast cells or kinin formation. Acute allergic angioedema is often caused by drugs (including antibiotics and non-steroidal anti-inflammatory drugs), foods, infections, insects, various organic substances (i.e. latex, preservatives, formaldehyde, etc.), and other allergens such as animal danders, dust mites, pollens and molds. Common triggers in children are infections including the viruses Coxsackie A, Epstein-Barr virus, Hepatitis B, and Herpes simplex. Bacterial causes include otitis media, pharyngitis, sinusitis and urinary tract infections. Parasitic infections causing angioedema include filariasis, strongyloides and toxocara. Physical factors can cause mast cell release causing angioedema. These include exposure to cold, heat, pressure, the sun and vibration. In the patient above, the dental work would have exposed the child to pressure and vibration and possibly to changes in heat and/or cold.

The differential diagnosis for angioedema includes:

  • Cellulitis of the face
  • Cheilitis granulomatosa (i.e. recurrent angioedema episodes with permanent enlargement of the lip)
  • Contact dermatitis of the face
  • Dermatomyositis
  • Hypereosinophilia
  • Hypothyroidism including myxedema coma
  • Lymphedema
  • Melkersson-Rosenthal syndrome (i.e. recurrent facial edema, fissured tongue, occasional facial nerve palsy)
  • Superior vena cava syndrome
  • Systemic lupus erythematosus
  • Tumors of the head and neck

Because of the rapid onset, neoplasms and infections can usually be ruled out as a cause of the edema. Hematomas can also cause edema and can be diagnosed by their color, and cervicofacial emphysema,which can usually be diagnosed by the “crepitus” of the swollen tissues.

Learning Point
Acute intraoral leucoplakic lesions are most commonly caused by trauma that usually has a concomitant history and presents with an usually single, ill-defined painful area with a smooth surface and erythematous or white border. These are treated symptomatically with anesthetics and coating agents to relieve pain. Occasionally steroids are used to help ulcers heal faster. Most trauma heals in 7-10 days.

Intraoral lesions associated with leucoplakia that may present acutely includes:

  • Trauma
    • Biting
    • Accidental trauma
    • Chemical injury
    • Electrical injury
  • Infections
    • Bacterial
      • Acute necrotizing ulcerative gingivitis – associated with spirochetes and Prevotella intermedia
      • Streptococcus Group A
    • Viral
      • Coxsackie – Hand-foot-mouth disease, herpangina
      • Heck’s disease – viral induced multi-focal hyperplasia of the oral mucosa
      • Herpes – primary or secondary infection
      • Measles
      • Mumps
      • Varicella
    • Fungal
      • Candida
  • Salivary gland dysfunction
    • Mucocoele
    • Ranula
  • Other
    • Angioedema
    • Bohn’s nodules
    • Medications
    • Retained food

Questions for Further Discussion
1. What are the indications for an evaluation for hereditary angioedema?
2. What are the treatments available for angioedema?
3. What are the indications for consultation with dentistry for intraoral lesions?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Edema and Hives.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Baxi S, Dinakar C. Urticaria and angioedema. Immunol Allergy Clin North Am. 2005 May;25(2):353-67, vii.

Pintos A. Pediatric Soft Tissue Lesions. Dental Clinics of North America. 2005;241-258.

Krishnamurthy A, Naguwa SM, Gershwin ME. Pediatric angioedema. Clin Rev Allergy Immunol. 2008 Apr;34(2):250-9.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    12. Evidence from scientific studies related to the patients’ health problems is located, appraised and assimilated.
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Interpersonal and Communication Skills
    17. A therapeutic and ethically sound relationship with patients is created and sustained.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

    Bridgett Schmidt, DDS
    Pediatric Dental Resident, University of Iowa College of Dentistry