Differential Diagnosis for a 58-year-old Diabetic Female with a Lesion on the Right Side of the Mouth

After exposure to a grandchild with hand, foot, and mouth disease, several diagnoses should be considered for the lesion on the right side of the mouth in a 58-year-old diabetic female. The differential diagnoses can be categorized as follows:

• Single Most Likely Diagnosis

  • Hand, Foot, and Mouth Disease (HFMD): Although HFMD is more common in children, adults can contract the disease, especially after exposure to an infected child. The presence of a lesion on the mouth after such exposure makes this a highly plausible diagnosis.

• Other Likely Diagnoses

  • Herpes Simplex Virus (HSV) Infection: Given the patient's diabetic status, which might impair immune function, and the location of the lesion, HSV could be a likely cause. HSV infections can manifest as oral lesions.
  • Aphthous Ulcers: These are common in the general population and could be exacerbated or triggered by stress, immune system changes, or other factors, including diabetes.
  • Traumatic Ulcer: A lesion could result from trauma to the mucosa, which might not heal properly in a diabetic patient due to impaired wound healing.

• Do Not Miss Diagnoses

  • Oral Cancer: Although less likely, any new oral lesion, especially in an adult, warrants consideration of oral cancer, particularly if the patient has a history of tobacco or alcohol use. Diabetes might also increase the risk of certain infections and potentially some cancers.
  • Necrotizing Ulcerative Gingivitis (NUG) or other severe gum diseases: These conditions can cause lesions and are more common in individuals with poor oral hygiene or compromised immune systems, such as diabetics.
  • Varicella-Zoster Virus (VZV) Reactivation (Shingles): If the lesion is part of a more widespread rash, VZV reactivation should be considered, especially in an adult who may have had chickenpox as a child.

• Rare Diagnoses

  • Primary Syphilis: The lesion could be a chancre, which is the primary lesion of syphilis, although this would be less common and typically associated with a history of unprotected sexual contact.
  • Histoplasmosis or other fungal infections: In immunocompromised individuals, including those with poorly controlled diabetes, fungal infections can cause oral lesions.
  • Erythema Multiforme: A skin condition that can cause oral lesions, often in response to an infection or medication.