Recurrence of zosteriform lesions on the contralateral dermatome: A diagnostic dilemma

Sir,

Zosteriform vesicular lesions of the skin could be due to either herpes zoster (caused by varicella zoster virus) or zosteriform herpes simplex (caused by herpes simplex virus). Recurrence of zosteriform vesicular lesions in the contralateral dermatome has been rarely reported, that too, only in immunocompromised individuals. Herein, we report the recurrence of zosteriform vesicular lesions on the contralateral dermatome in an immunocompetent individual.

A 40-year-old man came with the complaints of painful blisters on the left side of his chest wall and the back for the past two days. He also had a history of similar lesions on the corresponding region on the right side of his body four years ago, which was not investigated or treated, and healed spontaneously in 10 days leaving some residual scars. He also gave history of chicken pox at 7 years of age. On examination, grouped vesicles on an erythematous base were seen distributed along the left T4-5 dermatomes, suggestive of herpes zoster or zosteriform herpes simplex. Postinflammatory hypopigmented scars were seen on the right T4 dermatome suggestive of post-zosteriform vesicular lesions sequelae [Figure 1]. His complete blood count was normal. His fasting blood sugar and postprandial blood sugar levels were within normal limits. Tzanck smear from the vesicles showed multinucleated giant cells [Figure 2]. His human immunodeficiency virus - enzyme linked immunosorbent assay (HIV-ELISA) was negative. Viral culture, polymerase chain reaction (PCR), and direct fluorescent antibody staining to confirm the causative virus could not be performed due to logistic constraints. We concluded that the patient had recurrence of zosteriform lesions on the left T4-5 dermatomes, of which T4 is the corresponding contralateral dermatome to the previous episode. We had a diagnostic dilemma as we did not have the laboratory evidence for the causative organism which could be any of the following (each of which is very rare in immunocompetent individuals):

Figure 1.

Grouped vesicles on left T4 and T5 dermatomes and postinflammatory hypopigmented scars on right T4 dermatome

Figure 2.

Multinucleate giant cell (Leishman stain, ×100)

1. Recurrence of herpes zoster on the contralateral dermatome.

2. Recurrence of zosteriform herpes simplex on the contralateral dermatome.

3. The first episode being herpes zoster and the second, zosteriform herpes simplex on the contralateral dermatome, and vice versa.

Herpes zoster has been reported to recur in the corresponding contralateral T10 dermatome in a patient with HIV (duplex symmetricus).[1] It also has been reported involving T8 to T10 dermatomes in an immunocompromised female patient with scarring of the same dermatomes on the other half of the body.[2] However, diagnosis of etiological agent was not confirmed in both these reports. Some authors believe that recurrent zoster is an extremely uncommon event and most of the cases clinically diagnosed to be recurrent herpes zoster turned out to be zosteriform herpes simplex on confirming the etiological agent.[3] Recurrence of zosteriform herpes simplex is common and usually it recurs on the same side.[4] However, zosteriform herpes simplex occurring in the contralateral dermatome has been reported in animal studies.[5]

We report this case and stress the importance of identifying the causative organism as proper diagnosis will lead to more accurate therapy. IgG and IgM estimation by ELISA for herpes simplex virus is relatively cheaper and can be routinely performed, as compared with PCR and viral culture.