|Year : 2021 | Volume
| Issue : 2 | Page : 81-82
Characteristics of the blisters of varicella-zoster viral infection on cutaneous optical coherence tomography
Wei-Yu Alex Chen1, Cheng-Yi Chang2, Ting-Wei Chang2, Chung-Hsing (Miriam) Chang3
1 Skin Institute, Department of Dermatology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien, Taiwan
2 Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
3 Skin Institute, Department of Dermatology, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation; Institute of Medical Sciences, Tzu Chi University; Doctoral Degree Program in Translational Medicine, Tzu Chi University and Academia Sinica, College of Medicine, Tzu Chi University, Hualien County 970, Taiwan
|Date of Submission||07-Aug-2020|
|Date of Decision||08-Dec-2020|
|Date of Acceptance||28-Dec-2020|
|Date of Web Publication||18-May-2021|
Dr. Chung-Hsing (Miriam) Chang
Doctoral Degree Program in Translational Medicine, Tzu Chi University and Academia Sinica, College of Medicine, Tzu Chi University, Hualien County 970,
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Chen WYA, Chang CY, Chang TW, Chang CH. Characteristics of the blisters of varicella-zoster viral infection on cutaneous optical coherence tomography. Dermatol Sin 2021;39:81-2
|How to cite this URL:|
Chen WYA, Chang CY, Chang TW, Chang CH. Characteristics of the blisters of varicella-zoster viral infection on cutaneous optical coherence tomography. Dermatol Sin [serial online] 2021 [cited 2022 Dec 3];39:81-2. Available from: https://www.dermsinica.org/text.asp?2021/39/2/81/316299
Herpes zoster and varicella are common, infectious, blistering dermatoses induced by the varicella-zoster virus (VZV). Prompt diagnosis and treatment would prevent further complications; however, an early diagnosis can be difficult in patients with atypical presentation or ambiguous skin lesions. Optical coherence tomography (OCT) is a noninvasive technique that enables micrometer-resolution transectional imaging of the epidermis and superficial dermis. Only few studies have illustrated the morphology of infective bullous dermatoses.,,,,, We attempted to identify the morphological features of VZV blisters under OCT and compared them with those of autoimmune blistering dermatosis to determine features that would facilitate early diagnosis and differentiation.
We enrolled 16 outpatients (9 men and 7 women; age: 12–90 years) who were treated from January to February 2018. Eight of these were diagnosed with herpes zoster, while two were diagnosed with varicella. The diagnosis was based on clinical presentations and typical Tzanck smear findings. Three patients with pemphigus vulgaris and three with bullous pemphigoid were also enrolled for comparison. In this case, the diagnosis was established based on histopathological findings and direct immunofluorescence. The duration of vesicle formation varied from 1 day to >5 days. Vesicular lesions on the trunk were examined by the OCT system after obtaining informed consent. The study was approved by the Research Ethics Committee of our hospital (IRB107-109-A).
The OCT system used in our study was the ITRI Skin Care OCT SD-05 (Industrial Technology Research Institute, Hsinchu, Taiwan), which adopts a 15-mW superluminescent diode with an 880-nm center wavelength and a 60-nm bandwidth light source. It has an optical resolution of 8 μm.
In very early lesions without a visible vesicle, the OCT system revealed multifocal, small intraepidermal vesicles with a vertical axis. Over time, multiple, ovoid, tiny vesicles with irregular borders developed and merged to form a clinically visible vesicle. In well-developed lesions, large septate polygonal bullae, arranged in a reticular pattern, would be noted. These morphological changes were observed even after a 5-day course of oral valacyclovir in one patient. The OCT findings of varicella vesicles were similar to those of the herpes zoster vesicles [Figure 1]a, [Figure 1]b, [Figure 1]c, [Figure 1]d. In patients with pemphigus vulgaris, the OCT examination revealed vesicles with a horizontal axis, whereas in those with bullous pemphigoid, long horizontal slits were observed [Figure 2]a and [Figure 2]b. However, we could not determine the level of split by OCT imaging alone.
|Figure 1: Cutaneous optical coherence tomography images of varicella-zoster virus-induced vesicles. The clinical pictures are presented on the right side, and the scanning area is indicated using white dotted lines. The width and depth of the image formed are 6 mm and 1 mm, respectively. (a and c) Optical coherence tomography images of herpes zoster and (d) image of varicella (a) Two small, ovoid intraepidermal vesicles with a diameter of 100–300 μm and a vertical long axis (white arrows) in an early erythematous papule noted on the right T8 dermatome for 1 day. (b) In small vesicles, optical coherence tomography revealing multiple intra- and subepidermal vesicles with vertical long axes and irregular borders (white arrow) in the vesicles on the left T10–11 dermatome for 5 days. (c) Residual polygonal-shaped, septate bullae in dried and crusted bullae after 5 days of oral valacyclovir treatment. (d) Optical coherence tomography images of varicella lasting for 3 days were similar to that of herpes zoster.|
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|Figure 2: Cutaneous optical coherence tomography images of pemphigus vulgaris and bullous pemphigoid. The clinical pictures are on the right side, and the scanning areas are indicated in white dotted lines. (a) An intraepidermal vesicle of pemphigus vulgaris developed for 2 days with a horizontal long axis (white arrow). The perilesional skin is normal, with the continuous hyperintensive band at the top representing stratum corneum and the thick whitish band indicating the other epidermal layers. (b) A large bullae of bullous pemphigoid lasting for about 1 week demonstrating a predominant, horizontal, subepidermal split (white arrows).|
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VZV-induced vesicles show unique features under OCT. Moreover, the vesicles of herpes zoster and varicella share similar morphological features. Our study demonstrates the evolutionary change from prevesicular erythematous papules to well-formed vesicles. These findings may explain the structural change following keratinocyte death and are consistent with the reported histopathological findings, including acantholysis and reticular degeneration. The vertical axis was the most prominent feature of the VZV-induced vesicles and may be related to a free nerve ending-centered spreading of the virus.
The study showed that the OCT system could detect microscopic epidermal changes before clinically visible vesicles were formed. Ovoid-shaped vesicles with a vertical long axis is a unique finding in the VZV blisters, which may help in early diagnosis and therefore enable prompt treatment and prevention of complications (e.g., postherpetic neuralgia). This is a rapid and noninvasive way of differentiating VZV infection from autoimmune blisters. However, the clinical manifestation and Tzanck smear are still the gold standard for diagnosing VZV infection.
Our study is limited by the small sample size and OCT resolution. Further studies that explore the diagnostic aspect of OCT are required.
We described the characteristic OCT features of VZV-induced blisters in different stages. The vertical long axis of the blisters may help differentiate the condition from autoimmune bullous diseases and facilitate early diagnosis.
Financial support and sponsorship
Conflicts of interest
Dr. Chung-Hsing (Miriam) Chang, an editorial board member of Dermatologica Sinica, had no role in the peer review process of or decision to publish this article. The other authors declared no conflicts of interest in writing this paper.
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[Figure 1], [Figure 2]