What is the primary condition indicated by the presence of vesicles on the hands and feet along with fever and mouth ulcers?

The primary condition indicated by the presence of vesicles on the hands and feet, along with fever and mouth ulcers, is Hand, Foot, and Mouth Disease (HFMD). This illness is most commonly caused by enteroviruses, particularly Coxsackievirus A16 and enterovirus 71.

HFMD typically presents with a characteristic clinical picture: patients will develop febrile symptoms followed by the appearance of painful oral ulcers—often affecting the tongue and buccal mucosa—and vesicular lesions on the palms of the hands and soles of the feet. The combination of these symptoms strongly suggests HFMD as the underlying diagnosis.

Other conditions may present with similar symptoms but do not manifest all the features typical of HFMD. For instance, herpangina, caused by the same virus family, usually presents with mouth ulcers but generally lacks the vesicular lesions on the hands and feet. Roseola infantum is characterized primarily by a sudden high fever followed by a rash, but does not present with vesicles or mouth ulcers at the onset. Impetigo is a bacterial skin infection that presents with pustules and crusted lesions usually around the face and is not associated with fever and oral ulcers to the extent seen in HFMD.

Thus,