Persico P, Roccabianca P, Corona A, Vercelli A and Cornegliani L. Detection of feline herpes virus 1 via polymerase chain reaction and immunohistochemistry in cats with ulcerative facial dermatitis, eosinophilic granuloma complex reaction patterns and mosquito bite hypersensitivity. Vet Dermatol. 2011; 22: 521-7.
Ulcerative dermatitis secondary to feline herpesvirus (FHV) infection is an uncommon disease that may resemble other cutaneous diseases such as eosinophilic granuloma and mosquito bite hypersensitivity. The investigators compared two methods for diagnosis of FHV-associated dermatitis – polymerase chain reaction (PCR) for amplification and detection of viral genetic material and immunohistochemistry (IHC) for detection of viral protein. Skin biopsy specimens from 62 cats with ulcerative skin lesions were tested by both methods. Immunohistochemistry for viral protein is considered the gold standard for diagnosis. PCR detected the presence of FHV genetic material in 12 samples, while IHC was positive in only two. Because of its high sensitivity and ability to detect latent or vaccinal virus, the authors concluded that PCR alone could result in misdiagnosis of FHV-associated dermatitis. They recommend PCR as an initial screening test, and, if positive, confirmation testing should be performed using IHC. [MK]