Herpes zoster reactivation after extracorporeal shock wave lithotripsy: A case report.

Herpes zoster is a reactivated varicella-zoster virus (VZV) infection of the sensory nerve ganglion, peripheral nerve, and its branches. Mechanical trauma to the nervous system can reactivate VZV. It is well known that extracorporeal shock wave lithotripsy (SWL) can produce mechanical damage to the tissue. We report a rare case of herpes zoster reactivation after SWL for treatment of 1.2 cm size renal stone in a 63-year-old male patient.

INTRODUCTION

Herpes zoster manifests as painful cutaneous eruptions over a single or two or more contiguous dermatomes. These eruptions are invariably unilateral, do not cross the midline and are most commonly distributed on the thorax but can appear anywhere on the body. It is well known that the varicella-zoster virus (VZV) lies dormant in the dorsal root nerve ganglion following a primary infection with the virus and can get reactivated at a later time. There are many risk factors for reactivation of VZV including mechanical trauma to the nervous system.[1] Extracorporeal shock wave lithotripsy (SWL) treatment for renal stone involves the delivery of shock waves through the skin, subcutaneous tissue, and underlying structures to the stone under focus. Although the maximum impact of shock waves is on the targeted stone, the shock wave effects can also involve adjacent organs in varying level of intensity.[2] Complications such as hematoma, adjacent organ contusion leading to inflammation have been mentioned as a potential side effect of SWL treatment. Therefore, it is possible that the nerve fibers along and adjacent to the pathway of shock waves can have varying degrees of trauma during SWL. We report a rare case of reactivation of VZV in the lower chest region following SWL treatment for a patient with right renal stone.

CASE REPORT

A 63-year-old male patient with a 2-month history of pain in the right flank region was diagnosed to have a 1.2 cm right renal calculus towards the upper pole [Figure 1]. The patient underwent right-sided SWL treatment. Postoperatively, the patient was asked to consume large quantities of fluids, and he was not given any pharmaceutical agents. Ten days later, the patient presented with multiple vesicular eruptions distributed along the dermatome of the 11th subcostal nerve on the right side with pruritus and severe burning pain. The patient had a history of herpes zoster infection at the age of 32 years in the same skin area. The diagnosis of reactivation of herpes zoster was made by the dermatologist, confirmed by biopsy of vesicular lesion and Tzanck smear examination. The patient was treated with acyclovir and the lesions started healing in 1 week [Figure 2]. Repeat X-ray KUB taken after 1 month showed that the stone fragments had cleared.

Figure 1

X-ray kidney, ureter, and bladder

Figure 2

Healing vesicles

DISCUSSION

Herpes zoster is a sporadic disease with an estimated lifetime incidence of 10–20%. The incidence of herpes zoster increases sharply with advancing age, roughly doubling in each decade past the age of 50 years. Histopathological findings of vesicular lesions include degenerative changes of epithelial cells such as ballooning, multinucleated giant cells, and eosinophilic intranuclear inclusions.

Following this primary infection, the VZV lies dormant in the dorsal root nerve ganglion. Reactivation of herpes zoster can be caused by decline in the cellular immune response. Circumstances such as advanced age, immunocompromised state, emotional and psychological trauma, malignancies, major surgeries, and mechanical trauma contribute to the reappearance of herpes zoster. Although minor procedures do not stress the immune system to cause reactivation of the VZV, mechanical trauma, and local inflammation may play a role in reactivating the VZV. The usual time of reactivation varies and depends on the type of precipitating factors.

Studies done by Kabalin et al.,[3] Schelling et al.,[4] and Deliveliotis et al.[5] suggest that shockwaves used for the treatment of diseases have the potential to effect and damage neural and muscle tissue. Reactivation of herpes zoster lesions after SWL has not been reported in the literature so far. However, similar lesions namely zosteriform lichen planus lesions have been reported earlier.[6]

In our case, the patient had no other precipitating factors for reactivation of herpes zoster other than SWL treatment. The distribution of lesions in our patient was limited to the field of particular dermatome and did not cross the midline. The pathological confirmation of herpes zoster was also made in this case.

CONCLUSION

SWL can be a trigger factor for reactivation of herpes zoster in patients with dormant virus in the same dermatome.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.