‘Vesicular eruption in COVID‐19 – to exclude varicella’: reply from the authors

Dear Editor, We and agree with Drs Lim and Tey on the need to exclude varicella in vesicular eruptions in patients with COVID‐19, as this diagnosis has important implications.¹

Once it is established that some patients with COVID‐19 can have a vesicular eruption,² there is a need to characterize this group of patients further. The association of some of these lesions with herpesvirus infections is very likely. One patient was excluded from our study with a diagnosis of varicella or disseminated herpes zoster. The list of case reports or case series is growing fast,³ and other authors have shown that patients with COVID‐19 can have a vesicular eruption with presence of several herpesviruses.⁴ Their images show haemorrhagic bullae of different sizes and with a diameter > 1 cm, larger than the eruption described in our paper,² with many equal, 2–3‐mm vesicles. As the paper by Drs Lim and Tey does not include pictures, we wonder whether this could be a sign suggesting herpesvirus infection (including varicella).

However, other reports have described a histological pattern of acantholysis and dyskeratosis with a suprabasal unilocular vesicle, different from varicella histology, indicating that at least some patients can have a disease that is not varicella. The diagnosis of these eruptions includes pseudoherpetic Grover disease,⁵ or they might be due to SARS‐CoV‐2 infection.

We suggest that further research should be done with consecutive patients, optimally including lymphocyte count, histology and/or Tzanck smear, and SARS‐CoV‐2 and herpesvirus detection in the vesicles, to delineate better the possible diagnoses for patients who show a vesicular eruption associated with COVID‐19.