Table 1.

Summary of Etiopathogenetic Mechanisms of COVID-19 Skin Manifestations

Type of Skin Manifestation	Localization	Frequency	Etiopathogenetic Mechanism
Maculo-papular rashes	Chest, arms	Most frequent in adult patients	Adverse drug reactions; immunological activation against the virus; Herpesviruses 6–7 reactivation
Chilblain-like rashes	Feet	Most frequent in young patients	INF-I mediated inflammatory response
Livedo racemosa, retiform purpura and acral ischemia	Arms, buttock	Less frequent, elderly patients	Intravascular thrombosis correlated to COVID-19 severity
Vesicular rashes	Trunk, arms	Frequent in adult patients	Eruption caused by SARS-COV-2; Herpesviridae co-infection
Urticaria	Trunk, face	Frequent in adult patients	Triggered by Covid-19 or by drugs used for the systemic disease
AGEP/EM	Trunk	Rare	AGEP: Drug reaction (hydroxychloroquine) EM: immune response to SARS-CoV-2 or hypersensitivity reaction to drugs elicited by the cytokines cascade triggered by SARS-CoV-2