臨床
水痘・帯状疱疹ウイルス抗原キットの使用経験
2021 年 114 巻 4 号 p. 263-266
詳細
2021 年 114 巻 4 号 p. 263-266
Diseases caused by varicella zoster virus (VZV) infection, such as Ramsay Hunt syndrome and pharyngolaryngeal herpes zoster, are commonly encountered in clinical practice.
They are usually diagnosed by their characteristic physical findings, such as formation of blisters in a localized area on one side of the body, and immediately treated with anti-herpes virus agents. Results of conventional serological tests for VZV antigen and antibodies require several days to obtain results and therefore, usually arrive only after the start of treatment. In recent years, a VZV antigen detection kit has been developed that has made diagnosis possible within a shorter time. The new detection kit is expected to be helpful for differentiating VZV infection from herpes simplex virus infection in difficult cases, and also to confirm the diagnosis in patients with an atypical presentation. We report our experience with the use of this kit in 4 cases of Ramsay Hunt syndrome (including 1 case with pharyngeal herpes zoster and 1 case with pharyngolaryngeal herpes zoster) and 1 case of oral herpes simplex infection at our department.
Of the 4 cases of Ramsay Hunt syndrome, the test results with the kit were positive in 2 cases in which the samples were obtained from the skin of the auricle. In one case, the test specimen was collected from a pharyngeal erosion and the test result with the antigen kit was positive. In another case, a specimen obtained from a pharyngeal erosion tested negative with the antigen kit, but tested positive by the fluorescent antibody (FA) method at a later date.
As previously reported, the detection sensitivity of the kit for samples obtained from erosions and ulcers may be lower than that for samples obtained from blisters and pustules.
Absence of cross-antigenicity with herpes simplex infection was confirmed.
In the case of mucosal lesions, the antigen kit may yield false-negative results in a relatively high percentage of cases. It is considered desirable to collect a sufficient amount of test sample and to use an antigen qualitative test, such as the FA method, in addition, as necessary.
