A 65-year-old woman with chronic lymphoid leukemia presented with vesicles, pustules and scabs on her back, face, chest and abdomen (Figures 1 and 2), considered to be either acute generalized exanthematous pustulosis or varicella zoster, and treatment was begun with acyclovir and a PCR test for varicella zoster. Due to the delay in obtaining PCR results and the risk of exposure to acyclovir, a Tzanck test was requested, confirming herpes virus infection (Figure 3) attributed to varicella zoster. The acyclovir treatment was completed, and a positive varicella zoster PCR report was ultimately received.

Figures 1
and 2. Multiple erythematous vesicles, with some generally distributed pustules and scabs.

Figure 3
Tzanck test: H-E40X, epithelial cells with multinucleation and hazy nuclei with nuclear molding.

The Tzanck test is a rapid, simple and inexpensive test for examining vesicular lesions and confirming herpes virus infection. It has the limitation of not differentiating between infections caused by herpes simplex virus 1, 2 or 3, but it has good operational performance (40-80% sensitivity and up to 100% specificity) when there is doubt regarding a diagnosis of herpes virus infection.

References

1. Wanat KA, Domínguez AR, Carter Z, et al. Bedside diagnostics in dermatology: Viral, bacterial, and fungal infections. J Am Acad Dermatol. 2017 Aug; 77(2): 197-218

2. Ozcan A, Senol M, Saglam H,et al. Comparison of the Tzanck test and polymerase chain reaction in the diagnosis of cutaneous herpes simplex and varicella zoster virus infections. Int J Dermatol. 2007 Nov; 46(11): 1177-9.

Notes

Author notes

^* Correspondence: Dr. Juan Sebastián Espinosa-Serna. Bogotá, D.C. (Colombia). E-mail: juansebastian_612@hotmail.com