Lip Problem Differential Diagnosis in the ED

When evaluating a patient with a lip problem in the emergency department (ED), it's crucial to consider a broad range of potential diagnoses to ensure appropriate management and to avoid missing critical conditions. The differential diagnosis can be organized into the following categories:

• Single Most Likely Diagnosis
  • Herpes Simplex Virus (HSV) Infection: This is often the most common cause of lip problems presenting to the ED, characterized by painful vesicles or ulcers. The high prevalence and typical presentation make it a leading consideration.
• Other Likely Diagnoses
  • Angular Cheilitis: Inflammation of the corners of the mouth, often due to fungal or bacterial infections, which can be painful and may interfere with eating or speaking.
  • Cold Sore (Recurrent Herpes Labialis): Similar to HSV infection but typically presents as a recurrence rather than a primary infection.
  • Impetigo: A contagious bacterial skin infection that can affect the lips, causing red sores, and can be treated with antibiotics.
  • Eczema (Atopic Dermatitis): Can cause dry, itchy, and inflamed skin on the lips, often part of a larger skin condition.
• Do Not Miss Diagnoses
  • Lip Cancer: Although less common, any persistent, non-healing lesion on the lip should raise suspicion for cancer, particularly in patients with risk factors like smoking or excessive sun exposure.
  • Cellulitis: A bacterial infection of the skin and subcutaneous tissues that can spread rapidly and become severe if not treated promptly with antibiotics.
  • Erythema Multiforme: An immune-mediated condition that can cause lip lesions, among other symptoms, and may be associated with infections or medications.
• Rare Diagnoses
  • Melkersson-Rosenthal Syndrome: A rare neurological disorder characterized by recurrent, often unilateral, facial paralysis or weakness, swelling of the face and lips, and the development of folds and furrows in the tongue (fissured tongue).
  • Sarcoidosis: A condition that can cause inflammation in various parts of the body, including the skin, and may rarely present with lip lesions.
  • Actinic Cheilitis: A condition caused by prolonged exposure to the sun, leading to inflammation of the lips, which can be a precursor to squamous cell carcinoma.

Each of these diagnoses has distinct features and management strategies. A thorough history, physical examination, and sometimes additional diagnostic tests are necessary to determine the cause of a lip problem and to guide appropriate treatment in the ED.