Bilateral asymmetrical herpes zoster.

A 26-year-old well-nourished male presented with vesicular eruptions and burning pain over both sides of the abdomen. On dermatological examination, multiple vesicular eruptions were seen along T8 dermatome on the right side and along T9 dermatome on the left side of the abdomen [Figure 1]. Eruptions were fully developed from posterior to the anterior part on both sides, but along different dermatomes [Figure 2]. Routine blood tests were normal. Human immunodeficiency virus test was negative. Renal and liver function tests were normal. There was no history suggestive of immune defect. There was history of stress one week prior. General physical and systemic examinations were normal. Patient was given acyclovir 800 mg 5 times daily with other symptomatic treatment. There was a dramatic improvement in skin lesions as well as pain within 7 days.

Figure 1

Fully developed vesicular eruptions along T8 dermatome on the right side and T9 dermatome on the left side

Figure 2

Eruptions were fully developed up to the anterior part

Herpes zoster is caused by a varicella-zoster virus (VZV). This infection affects spinal or cranial nerves resulting in unilateral vesicular eruptions and severe radicular burning pain. Herpes zoster affects a dermatome innervated by the concerned nerve.[1]

Herpes zoster is unilateral in most cases.[2] Usually, it involves a single dermatome. Multiple dermatomal involvement is rare. When only one-half of the body is involved, it is called herpes zoster duplex unilateralis. When both halves are involved it is called herpes zoster duplex bilateralis. Herpes zoster contralaterally on the same dermatome is called herpes zoster duplex symmetricus. Bilateral asymmetrical distribution of herpes zoster is very rare particularly in an immunocompetent adult. In this case, there were fully developed eruptions on both sides of the abdomen and on different dermatomes. Patient was healthy, immunocompetent adult. Laboratory finding did not reveal immunosuppression. Some local factors like the number of viral copies present in the cell or a local trauma to nerve root ganglion, along with systemic factors play a role in reactivation of VZV.[3] Local trauma might have played a crucial role in reactivation of VZV in this case. This case with bilateral asymmetrical herpes zoster in an immunocompetent healthy adult emphasizes further studies about theory of reactivation of VZV.