Recurrence of herpes zoster in a young woman with IgG3 deficiency

herpes zoster occurs at a low frequency among immunocompetent individuals. Particularly in young people, recurrent herpes zoster is known to be rare [1]. As the authors found a case of a young woman with no particular past medical history in whom herpes zoster recurred and IgG subclass deficiency was diagnosed on additional testings, we herein report the case. The patient was a 32-year-old woman who visited the Department of Pain Medicine after having been diagnosed with post-herpetic neuralgia. A year and two months before she visited our hospital, she had experienced symptoms including erythema, grouped vesicles, and piercing pains that began at the part just above the nipple (T3 dermatome) on the left chest. She was diagnosed with herpes zoster, which was treated and cured completely with no apparent sequelae. Six weeks prior to her visit to our hospital, however, the erythema and pains recurred at the same site, and the dermatological clinic diagnosed it as herpes zoster. After the administration of an anti-viral agent for a week and 1,800 mg of gabapentin for six weeks, the skin lesion resolved without leaving a scar, but allodynia, paresthesia, and hyperalgesia continued at the site and, therefore, the patient visited the present hospital and was diagnosed with post-herpetic neuralgia. The patient had been suspected of suffering from narcolepsy, but had not received any treatment. She had no previous medical history of hypertension, diabetes, frequent upper respiratory infections, or other infectious diseases. As it was rare that herpes zoster recurred at the same site in a young patient with no particular past medical history, the patient was examined for the presence of an immune disorder. She underwent tests including those for immunoglobulin G (IgG) subclass and anti-nuclear antibody, IgG, IgA, IgM, IgD, vitamin D3, and human immunodeficiency virus (HIV). The laboratory tests revealed, IgG3 levels as low as 20.2 mg/dl (normal range 21.8–176.1 mg/dl) but there were no other specific findings. Six months later, her testing showed an IgG3 level of 16.0 mg/dl. The case was therefore diagnosed as IgG3 deficiency. The patient was administered herpes zoster vaccine once, and it was confirmed after six months that antibody had not been formed. Our treatment goals should be focused on restoration of normal function, improved quality of life, reduction of the use of medication, and prevention of relapse of chronic symptoms. Thus, the patient is currently being treated for post-herpetic neuralgia through drug treatment …