Differential Diagnosis for Water Mouth Around Mouth

The symptom of water mouth around the mouth, potentially indicative of hand, foot, and mouth disease (HFMD), requires a comprehensive differential diagnosis to ensure all possible causes are considered. Here's a categorized approach:

• Single Most Likely Diagnosis

  • Hand, Foot, and Mouth Disease (HFMD): This is the most likely diagnosis given the symptom description. HFMD is a common viral illness in children characterized by sores in the mouth and a rash on the hands and feet. The presence of water mouth (likely referring to vesicles or ulcers) around the mouth is consistent with HFMD.

• Other Likely Diagnoses

  • Herpangina: Caused by coxsackieviruses, herpangina presents with small, painful blisters or ulcers at the back of the mouth, which could be mistaken for the symptoms described.
  • Aphthous Stomatitis (Canker Sores): Although typically not as widespread or accompanied by the hand and foot rash, canker sores can cause significant oral discomfort and could be considered in the differential.
  • Impetigo: A highly contagious skin infection that can cause sores or blisters around the mouth, though it's more superficial and not typically associated with oral ulcers.

• Do Not Miss Diagnoses

  • Primary Herpes Simplex Virus (HSV) Infection: HSV can cause severe oral and genital infections. Oral HSV infection (gingivostomatitis) can present with painful vesicles and ulcers throughout the mouth, which could be confused with HFMD.
  • Erythema Multiforme: A skin condition characterized by target lesions, which can sometimes involve the mucous membranes, including the mouth. It's crucial to identify this condition due to its potential association with more severe diseases.
  • Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis: Although rare, these are life-threatening conditions usually triggered by medications or infections, characterized by widespread skin and mucous membrane lesions.

• Rare Diagnoses

  • Enterovirus 71 Infection: While more commonly associated with HFMD, certain strains like EV-71 can lead to more severe neurological and systemic complications.
  • Kawasaki Disease: An acute febrile illness of childhood that can present with oral changes (such as strawberry tongue), rash, and other systemic symptoms. It's rare but important to consider due to its potential for cardiac complications.
  • Autoimmune Disorders (e.g., Pemphigus Vulgaris): These conditions can cause blistering of the skin and mucous membranes, including the mouth, though they are much less common in children and would present with a different constellation of symptoms.