A child with a greyish white lesion in the oral cavity is likely to be diagnosed with which condition?

The presence of a greyish white lesion in the oral cavity of a child is most commonly associated with herpangina, a viral infection caused primarily by coxsackievirus. The lesions in herpangina typically appear as vesicles and then ulcerate, leading to greyish white patches in areas such as the soft palate and tonsillar regions. This condition often presents with accompanying symptoms like fever, sore throat, and difficulty swallowing, which align with the classic symptoms of herpangina.

In contrast, hand-foot-and-mouth disease, while also caused by coxsackievirus and characterized by lesions, typically involves oral ulcers that may appear red rather than greyish white. Stomatitis can refer to inflammation of the oral tissue but doesn't usually present specifically with the distinctive greyish white lesions seen in herpangina. Similarly, oral thrush, which is a yeast infection caused by Candida, presents as creamy white lesions rather than greyish white, making it distinct from herpangina. Thus, when considering the specific characteristics of the lesions, herpangina is the most fitting diagnosis.