Skin lesions observed in relation to SARS-CoV-2
Besides the typical symptoms described above, more and more reports about skin lesion and lesions of the vascular system observed in patients tested positive for SARS-CoV-2 and patients suspected to be infected by SARS-CoV-2 are coming up in countries all over the world (39, 40 ). The percentage of patients with skin lesions varies from lower than 1% to up to 20% of all SARS-CoV-2 patients and has to be estimated exactly in systematic studies on this issue.
The spectrum of skin lesions in SARS-CoV-2 patients described and published so far contain skin lesions occurring in other infectious and viral diseases such as maculopapular-exanthema, vesicular exanthema or urticarial eruptions (39, 41-46 ). Furthermore, the skin lesions might also be related to virus induced or indirectly induced vascular dysfunctions, such as livedo reticularis, petechiae or cutaneous acro-ischemia (39-42, 47 ). Chilblain lesions have been described as well (48-50 ). Considering frequency, most reports exist on maculopapular exanthema/vesicular exanthema, urticarial, and chilblain lesions (41 ). Less reports exist on acro-ischemia or livedo reticularis and other skin lesions.
Based on the largest collection of skin lesions from patients from Spain, lesions have been recently categorized into 5 main groups (41 ) summarized in Fig. 4A-E.
  1. Vesicular eruptions, predate in about 15% COVID-19 symptoms or occur with symptoms, last 10-12 days and go along with COVID-19 with intermediate severity, patients affected are middle aged and lesions are accompanied by moderate itch (Fig. 4A).
  2. Maculopapular exanthema manifests together with COVID-19 symptoms, often in more severe cases with a mortality rate up to 2%, lasts 7-9 days and is in over 50% of the cases accompanied by itch (Fig. 4B).
  3. Urticarial eruptions occur at the same time as other symptoms in more severe COVID-19 cases are accompanied by itching and last 6-8 days (Fig. 4C).
  4. Livedo or necrosis and other vasculitis forms tend to occur in older and more severe cases, with relatively high mortality (up to 10%) and the onset was together with COVID-19 symptoms (Fig. 4D).
  5. Chilblain was observed in younger patients with mild or even asymptomatic courses, the onset is late, duration 12-14 days and in one third are the lesions accompanied by pain and itch (22-23 ) (Fig. 4E).