A Review of Atypical Cutaneous Histological Manifestations of Herpes Zoster

Abstract

The clinical and histopathological features of herpes zoster (HZ) are usually straightforward. Atypical histological presentations, in the absence of the classical viral cytopathic changes, are well documented and can make the diagnosis of HZ extremely difficult. Herein, we review the existing literature on atypical cutaneous histological manifestations of the disease, with emphasis on the subtle clues, use of immunohistochemistry, and potential pitfalls.

Keywords: atypical presentation; herpes zoster; varicella-zoster virus.

Figure 1

Typical histology of cutaneous VZV infection: (A,B) Suprabasal separation consequent to ballooning, reticular degeneration, and keratinocytes necrosis; hematoxylin and eosin (H&E) ×10 and ×100. (C) Steel grey nuclei with peripheral condensation of chromatin can be seen; (H&E) ×200. (D) Multinucleated cells are common; (H&E) ×200.

Figure 2

Subtle changes in HZ: (A,B) Interface vacuolar damage, erythrocytes extravasation, and perineural inflammation may be the only pathological features identified; (H&E) ×200.

Figure 3

IHC for VZV shows diffuse and strong membranous staining in active lesions ×200.

Figure 4

(A) Necrotizing VZV folliculitis; (H&E) ×200. (B) Nuclear staining for VZV IHC in follicular epithelial remnants; (H&E) ×200.

Figure 5

(A) Dense perifollicular lymphoid cell infiltrate in the absence of viral cytopathic changes in the epidermis and follicular epithelium; (H&E) ×100. (B) The lymphocytes are T-cells as confirmed by CD3 diffuse staining ×100. Necrosis and cytopathic changes may be found after numerous serial sections are examined.

Figure 6

A rare clinical presentation of bilateral vasculitic HZ in an immunosuppressed patient. He also had radiculopathy with leg weakness (mimicking Guillain–Barré neuropathy). This all resolved with acyclovir.

Figure 7

Leucocytoclastic vasculitis underlying a blister with VZV cytopathic changes; (H&E) ×200.