A patient presents with painful blister along the chest wall. All of the following tests are useful for diagnosis except?

Ans. (d) LDH levels.Note vesicles along the dermatome of a thoracic nerve caused by varicella-zoster virus. Laboratory studies for VZV include the following:* Direct fluorescent antibody (DFA) testing of vesicular fluid or a corneal lesion* Polymerase chain reaction (PCR) testing of vesicular fluid, a corneal lesion, or blood* Tzanck smear of vesicular fluid (lower sensitivity and specificity than DFA or PCR).Image source- style="font-family: Times New Roman, Times, serif">