1. Skin manifestations similar to those in other viral
infections
During the COVID-19 outbreak in China, it was not a focus to document
skin manifestations. Consequently, skin rash has only been reported in 2
out of 1.099 infected patients (0.2%) (21). In contrast, a study by
dermatologists from Italy reported skin manifestations in 18/88 patients
(20.4%) with COVID-19 (4). Cutaneous manifestations seen were either
erythematous rash (n=14), widespread urticaria (n=3), or chickenpox-like
vesicular rash (n=1). In Spain, among 375 patients with suspected or
confirmed COVID-19, maculopapular eruptions (MPEs), sometimes similar to
pityriasis rosea, were observed in 47% of the cases, urticarial lesions
in 19% and vesicular eruptions of the trunk in 9% (22). Another case
of urticaria was presented in France (Figure 2A)(23) and patients with
morbilliform exanthem in the USA (Figure 2B)(24). Varicella-like lesions
predominantly on the trunk were described in 22 patients with proven
COVID-19 infection in Italy (25).
Predominance of vesicles was reported in 54.5% and generally mild
itching in nine (40.9%) patients. The vesiculopapular exanthem appears
to develop early in the course of the disease (Figure 2C (26))(22,26).
Two patients with bilateral flexural exanthems resembling systemic
drug-related intertriginous exanthems (SDRIFE), one with axillary
purpuric lesions associated with thrombocytopenia, have been published
(Figure 2D) (27). A prospective study
from France reported a prevalence of 5/103 (4.9%) and confirmed
association of pruritic erythematous rash (n=2) and urticaria (n=2) with
COVID-19 infections (28); they additionally observed one oral herpes
simplex virus type 1 reactivation. The histopathological picture of
exanthematic skin lesions generally resembles that of viral exanthems.
However, in individual patients, early microthrombi and an interface
dermatitis with necrotic keratinocytes surrounded by lymphocytes have
been reported (29).