We collected data on 429 cases from 3 to 16 April 2020, during the peak of the epidemic in Spain. Five cases were excluded for being compatible with other diagnosis (three herpes zoster and two psoriasis). Also, 31 patients with cutaneous lesions were excluded for not meeting the definition of confirmed or suspected COVID-19, and 18 were excluded because of missing information. The overall impression was that the majority of the excluded patients showed similar lesions, mostly described as acral. The final sample included 375 patients. The case fatality rate in the sample was 1·9%.
Consensus following review of the images led to the description of five major clinical patterns (Appendix S1; see Supporting Information). Nearly all of the patients could be classified into these groups, and a few unusual cases are highlighted in the description. The groups are as follows.
Acral areas of erythema–oedema with some vesicles or pustules (pseudo-chilblain) (19% of cases). These lesions may resemble chilblains and have purpuric areas, affecting the hands and feet (Figure 1a, b). They were usually asymmetrical.
Other vesicular eruptions (9%). Some presented on the trunk and consisted of small monomorphic vesicles (i.e. at same stages, unlike polymorphic vesicles in chickenpox) (Figure 1c). They may also affect the limbs, have haemorrhagic content, and become larger or diffuse.
Urticarial lesions (19%) (Figure 1d). These are mostly distributed on the trunk or dispersed. A few cases were palmar.
Other maculopapules (47%). Some of these cases showed perifollicular distribution and varying degrees of scaling (Figure 2a). Some were described as being similar to pityriasis rosea. Purpura was also sometimes present, either punctiform or on larger areas. A few cases showed infiltrated papules on the extremities, mostly the dorsum of the hands, that look pseudovesicular (Figure 2b) or resemble erythema elevatum diutinum or erythema multiforme (Figure 2c).
Livedo or necrosis (6%). These patients showed different degrees of lesions suggesting occlusive vascular disease, including areas of truncal or acral ischaemia (Figure 2d).
All of the patients shown had confirmed COVID -19. (a, b) Acral areas of erythema–oedema with vesicles or pustules (pseudo-chilblain). (c) Monomorphic (i.e. at same stages) disseminated vesicles. (d) Urticarial lesions.
All of the patients shown had confirmed COVID -19. (a) Maculopapular eruption. Some of the lesions are perifollicular. (b) Acral infiltrated papules (pseudovesicular). (c) Acral papules (erythema multiforme like). (d) Livedoid areas.
A few patients showed other manifestations such as enanthem or purpuric flexural lesions.
Dermatologists also perceived an increased number of cases of herpes zoster in patients with COVID-19.
Characteristics Associated With Each Clinical Pattern
The different clinical patterns were associated with differences in demographics and in other clinical manifestations (Table 1 and Table 2). Pseudo-chilblain lesions affected younger patients, lasted longer (mean 12·7 days), took place later in the course of COVID-19 disease and were associated with less severe disease (in terms of hospital admission, pneumonia, intensive care unit admission or mortality). These lesions could cause pain (32%) or itch (30%). Vesicular lesions appeared in middle-aged patients, lasted for a mean of 10·4 days, appeared more commonly than the other types (15%) before other symptoms and were associated with medium severity. Itching was common (68%).
Urticarial and maculopapular lesions showed very similar patterns of associated findings. They lasted for a shorter period (mean 6·8 days for urticarial and 8·6 for maculopapular), usually appeared at the same time as the other symptoms and were associated with more severe COVID-19 disease (2% mortality in the maculopapular sample). Itching was very common for urticariform lesions (92%) and occurred in 56% of cases of maculopapular lesions. Livedoid or necrotic lesions were seen in older patients with more severe disease (10% mortality). However, the manifestations of COVID-19 in this group were more variable, including transient livedo, with some having COVID-19 that did not require hospitalization.
The severity of the associated disease followed a gradient, from less severe disease in pseudo-chilblain to most severe in patients with livedoid presentations, as shown by the increasing percentages of pneumonia, hospital admission and intensive care requirements.
Of 71 patients with pseudo-chilblain, only one had a previous history of perniosis. The percentage with confirmed presence of SARS-CoV-2 in this group was 41%; lower than in the other morphological groups (Table 1).
Patients in the group with urticarial eruptions were receiving drugs more commonly than those with pseudo-chilblain or vesicular lesions, but less commonly than those with maculopapules or livedoid lesions, in relationship with increased severity.
We identified three familial clusters with lesions. One family had two siblings with pseudo-chilblain and another showing a generalized vesicular eruption with suspected COVID-19. Another two families showed clusters of lesions but did not have symptoms of respiratory COVID-19 and did not enter the study; each of the two families included two children, who simultaneously developed pseudo-chilblains.
The British Journal of Dermatology. 2020;183(1):71-77. © 2020 Blackwell Publishing