An Unusual Case of Herpes Zoster Complicated by Asymptomatic Phrenic Nerve Paralysis in a Hemodialysis Patient

Herpes Zoster (HZ) is the clinical manifestation of latent Varicella Zoster Virus (VZV) reactivation which can occur several decades after the early infection by Varicella Virus. Herpes Zoster usually affects the sensory neurons but may occasionally involve motor neurons corresponding to the dermatomes affected by skin lesions, resulting in flaccid paralysis of their muscles. Phrenic nerve paralysis is commonly caused by surgical or traumatic injuries, malignant tumors, neurodegenerative disorders or idiopathic diseases. However, in rare cases, it has been reported a diaphragmatic paralysis resulting from infection by Herpes Varicella Zoster Virus (VZV). We report a case of a 58 years old man, undergoing hemodialysis, who developed a left diaphragmatic paralysis after a typical Herpes Zoster rash involving the dermatome C3-C4 on the left side. The clinical and radiological results revealed no local causes of injury to the phrenic nerve. Hemidiaphragmatic paralysis was probably related to the infection by VZV. We asked ourselves if underdosing of the antiviral therapy (in the uremic patient) or the shortness of the treatment may have contributed to the development of this complication. However we believe that the risks resulting from overdosing outweigh the benefits. Therefore further studies, especially in ESRD, would be needed in order to evaluate if the dose adjustment and/or a prolongation of the antiviral therapy may have a protective effect on the onset of diaphragmatic paralysis.