Final answer:
The patient's symptoms suggest a diagnosis of a localized CMV infection. The absence of oral mucosal lesions, pruritis, and a negative Nikolsky sign support this diagnosis. Further tests can be done to confirm the presence of CMV and determine the viral load.
Step-by-step explanation:
The patient's symptoms of no oral mucosal lesions, pruritis, and a negative Nikolsky sign suggest a diagnosis of a localized CMV infection.
The diagnosis of a localized CMV infection can be achieved through direct microscopic evaluation of tissue specimens stained with routine stains and immunohistochemical stains. In this case, a negative Nikolsky sign indicates that there are no blistering or sloughing of the skin or mucous membranes upon gentle rubbing, which is inconsistent with conditions like pemphigus vulgaris.
Cultivation of the virus from saliva is still the method for detecting CMV in newborn babies up to 3 weeks old, and the patient's negative viral cultivation result from the saliva does not rule out a possible CMV infection. Further tests such as enzyme immunoassay and PCR can provide a higher sensitivity and determine the viral load.