Urticaria-like lesions in COVID-19 patients are not really urticaria - a case with clinicopathological correlation.

Dear Editor,

We have read with great attention the article by 1 considering urticarial lesions as a coronavirus disease 2019 (COVID‐19)‐associated skin manifestation. They observed two patients with erythemato‐oedematous lesions surrounded by whitish halo, thus similar to hives but without additional data on their evolution. A previous report of COVID19‐related urticarial lesions had also been first published by Recalcati. However, none of these two published articles detailed if the lesions were evanescent, as it is mandatory for urticaria, nor did a pathological study.

Madrid, Spain, has been considered by the World Health Organization as an area of SARS‐CoV‐2 of community transmission. Since then, we began to observe different skin manifestations in patients with COVID‐19 infection. We present the case of a patient with non‐evanescent urticarial lesions and its clinicopathological correlation.

A 60‐year‐old woman was admitted to the hospital for dry cough and pyrexia in the previous 3 weeks. In the last 5 days, she developed an urticarial eruption (Fig. 1). The patient had no relevant past medical history and had only suffered one episode of pompholyx 3 years ago. When the cutaneous rash appeared, she was not under any medication. She presented a bilateral interstitial pneumonia on X‐ray, and blood test revealed a mild lymphopenia (370/mm3) and increased liver enzymes (GOT, GPT, LDH, GGT three times normal). A cutaneous punch biopsy was performed showing slight vacuolar‐type interface dermatitis with occasional necrotic keratinocytes. No oeosinophils were encountered. These histological alterations were compatible with an erythema multiforme‐like pattern (Fig. 2).

Figure 1

Confluent weals on anterior (a) and posterior (b) trunk.

Figure 2

Haematoxylin and eosin. Slight vacuolar‐type interface dermatitis with occasional necrotic keratinocytes 10× (a), 20× (b) and 40× (c).

On follow‐up, the lesions were persistent on the same locations without evolving to blistering. Surprisingly, in the work by Marzano et al., reporting varicella‐like lesions on COVID‐19 patients, the histological image included in their report resembles our case.

In conclusion, we want to highlight that histopathological studies are important to characterize COVID‐19‐related skin lesions. In our experience, these urticaria‐like lesions may also appear in late phases and not only as early manifestations of COVID. Thus, this type of skin lesions should be further studied to clarify its relation with COVID‐19 and whether it may be useful to identify earlier COVID‐19 patients.

But we must remember that even today, when it seems that all of our patients are affected of COVID‐19 and all the skin diseases may be related to it, we have to ground on clinicopathological correlation and to maintain the same quality standards that we used to have before SARS‐CoV‐2 appeared. This will be the key to unravel our enemy in this battle.

Acknowledgement

The patients in this manuscript have given written informed consent to publication of their case details.

Funding sources

none to be declared.