Question

A 3-year-old boy presents with low-grade fever, painful oral ulcers, and vesicular rash on palms and soles. Several children in his daycare have a similar illness. Which of the following organisms is the most likely cause?

• A. Herpes simplex virus
• B. Coxsackie virus
• C. Varicella-zoster virus
• D. Streptococcus pyogenes

Hint:

Coxsackievirus A16 $\rightarrow$ Classic mild HFMD; Enterovirus 71 $\rightarrow$ HFMD with potential neuro/cardiopulmonary complications; Coxsackievirus A6 $\rightarrow$ Atypical/severe eczema coxsackium and onychomadesis (nail shedding).

Answer 1

The Correct Option is B

Concept:
Hand-Foot-and-Mouth Disease (HFMD) is a highly contagious, common viral exanthem of early childhood, frequently occurring in institutional settings like daycares and preschools.
It is caused by viruses of the Enterovirus genus within the Picornaviridae family, most commonly Coxsackievirus A16 and Enterovirus A71.
Explanation:
• HFMD presents characteristically with a mild prodrome of low-grade fever, malaise, and poor oral intake followed by the eruption of distinct mucocutaneous lesions.

• The oral enanthem consists of painful erythematous macules that rapidly evolve into small, shallow vesicles and ulcers located on the buccal mucosa, tongue, hard palate, and gingiva.

• The exanthem features non-pruritic, tender or painless oval, elliptical, or football-shaped vesicles on an erythematous base distributed symmetrically over the palms, soles, fingers, toes, and occasionally buttocks.

• Coxsackievirus A16 is the most frequent global cause of typical, mild HFMD, whereas Enterovirus 71 is associated with more severe neurological complications (e.g., aseptic meningitis, encephalitis, and acute flaccid paralysis).

• Herpes simplex virus (HSV-1) primarily causes herpetic gingivostomatitis involving anterior oral cavity and perioral skin without the characteristic palm-and-sole exanthem.

• Varicella-zoster virus produces generalized, highly pruritic polymorphic lesions in crops with a central/centripetal distribution.
Final Answer:
The clinical triad of fever, painful oral ulcers, and vesicular lesions on the palms and soles is typical of Hand-Foot-and-Mouth Disease caused by Coxsackievirus.