Cutaneous Clinico-Pathological Findings in Three COVID-19-Positive Patients Observed in the Metropolitan Area of Milan, Italy.
Reviewed by Dr Michelle Liang, National Skin Centre
The novel coronavirus SARS-CoV-2 has caused a global health pandemic with unprecedented medical, economic and social consequences as it continues to spread swiftly around the world. Although acute respiratory signs and symptoms are the most common presentation of the virus, increasing evidence has linked the virus to a myriad of other clinical effects. Cutaneous manifestations are being increasingly reported and consist of a highly variable spectrum, including viral exanthema, urticarial eruptions, vesicular or varicelliform, petechial and perniosis. In this paper, skin biopsies performed allowed greater understanding into the underlying pathogenetic mechanisms.
Patients 1 and 2 had a similar clinical presentation of maculopapular exanthema resembling viral exanthema. A typical viral exanthema may usually show mild spongiosis and superficial perivascular inflammation on histology. The presence of thrombosis within small vessels in patient 1, as well as widespread extravasated red cells suggestive vasculitis in patient 2 is very interesting. This correlates with reports of the virus causing a thrombophilic state in patients. Further data is required to determine the actual thrombotic risk to patients, but perhaps this information could be extrapolated to suggest that any COVID-19 patient presenting with similar exanthematous eruption should considered a candidate for anticoagulation.
Patient 3 had a slightly different clinical presentation, the lesions were more papular, with some areas of erosion and crusting, resembling a varicelliform eruption. The skin biopsy had interesting findings of dyskeratosis, multinucleated keratinocytes, balloon degeneration and necrosis of keratinocytes with a lichenoid infiltrate of lymphocytes. This calls to mind viral cytopathic changes found in herpes simplex and it is very likely that as the author’s suggest, the keratinocytes are damaged by cytokine cascade activation of cytotoxic and NK lymphocytes.
In summary, the 3 cases allowed us to better understand what cutaneous manifestations may arise in patients affected with the novel coronavirus SARS-CoV-2, the virus that causes COVID-19. Dermatologists should keep up to date with the increasing spectrum of cutaneous manifestations as we too have an important role to play in this global pandemic.