CPT® Code 87290

The CPT® Code 87290 refers to a laboratory test specifically designed for the detection of the Varicella zoster virus (VZV) antigen using an immunofluorescent technique. This test is crucial for identifying the presence of VZV in vesicular lesions or tissue samples. Varicella zoster virus is classified as a linear double-stranded, enveloped DNA virus that belongs to the herpesviridae family. It is primarily known for causing primary varicella infection, commonly referred to as chickenpox, which predominantly affects children. The clinical presentation of chickenpox includes fever and a generalized rash that evolves through distinct stages, starting from macular lesions to papular and finally to vesicular forms. In addition to causing chickenpox, VZV can also lead to a latent infection known as shingles, which is characterized by inflammation of a posterior nerve root. This condition results in the eruption of painful vesicular lesions associated with the sensory nerve ganglia. The laboratory test involves obtaining a sample through swabbing or scraping the affected vesicular lesions or inflamed tissue. The collected sample is then inoculated with antibodies specific to the Varicella zoster virus, which are conjugated to fluorescein isothiocyanate. This mixture is examined under an epifluorescence microscope. If the Varicella zoster virus is present in the sample, the antibodies will bind to the viral antigens, resulting in a bright green fluorescence, while non-infected surrounding cells will exhibit a dull red fluorescence. Although this immunofluorescent test is relatively rapid, it is important to note that it may be less sensitive compared to reverse transcription-polymerase chain reaction (RT-PCR) methods for detecting VZV.