Figure Legends
Figure 1 . SARS-CoV-2 attachment, internalization and replication cycle in epithelial cells and the main effect of antiviral agents. Attachment of SARS-CoV-2 spike protein (S) to angiotensin-converting enzyme 2 (ACE2) mediates endocytosis of the virus into the host cell. The cell entry of the virus depends on both the binding of viral S proteins to cellular receptors and priming S protein by the serine protease transmembrane protease / serine (TMPRSS) 2. Cepharanthine / human recombinant ACE2 and camostat mesylate are the viral entry inhibitors, which prevent the binding of S protein to ACE2 and priming, respectively. In the uncoating stage, virions are internalized by receptor-mediated endocytosis that the low pH in the endosome triggers the fusion of viral and endosomal membranes and the ssRNA (+) viral genome is released into the cytoplasm. Arbidol, chloroquine, hydroxychloroquine, and mefloquine block this uncoating stage. Transcription of the viral genome and proteolytic cleavage of the replicase polyprotein and resulting translating proteins are processed into the viral RNA-dependent RNA polymerase (RdRp). Lopinavir, ritonavir, remdesivir and favipiravir prevent proteolysis and activity of RdRp. Non-structural and structural proteins, including nucleocapsid proteins are expressed as sub-genomic RNAs. Salemectin and resveratrol may inhibit viral helicase activity, viral mRNA synthesis and the expression of nucleocapsid proteins. Assembly and budding of viral proteins and nucleocapsid occur at membranes of the endoplasmic reticulum (ER), the ER-Golgi intermediate compartment (ERGIC), and/or the Golgi complex. New SARS-CoV-2 virions are released by exocytosis.
Figure 2 . Diagnosis of SARS-CoV-2 infection through different diagnostic tests over time according to incubation period, disease onset, clinical disease and convalescence.
Figure 3 . Preventive measures for SARS-CoV-2 infection and control for healthcare providers. PPE, personal protective equipment (medical mask, eye/facial protection, gloves, long sleeve gown and waterproof apron). *Adequately ventilated room: natural ventilation with airflow of at least 160 L/s per patient, or negative-pressure rooms with at least 12 air changes per hour. Controlled direction of airflow when using mechanical ventilation (adapted from “WHO: Infection prevention and control during health care when COVID-19 is suspected”).111
Figure 4. Organization of an allergy clinic during the COVID-19 pandemic. Patients should be triaged to determine those in need of face-to-face consultation and those at risk of infection with SARS-CoV-2. Telehealth should be prioritized in allergy clinics. Procedures at high risk of generating airborne particles should be avoided. Patients should be motivated to notify their healthcare professionals in case of exacerbations or changes in their usual symptoms.
Figure 5. Practical considerations for allergy therapies during the COVID-19 pandemic. Continuation of second generation H1-antihistamines for the treatment of allergic rhinitis and urticaria, topical corticosteroids for atopic dermatitis, nasal corticosteroids for allergic rhinitis, and inhaled corticosteroids for asthma. Subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) for respiratory and venom allergies should be continued in non-infected individuals and patients recovered from COVID-19 and it should be suspended in patients diagnosed with COVID-19 or suspected of SARS-CoV-2 infection until resolution of COVID-19 is established. Biologicals should be continued, if possible as home self-administration, in patients non-infected or recovered from COVID-19 and they should be suspended in patients diagnosed with COVID-19 or suspected of SARS-CoV-2 infection until resolution of COVID-19 is established.
Figure 6 . Cutaneous manifestations of COVID-19. Several skin manifestations can be potentially associated with the disease: 1) local skin inflammation is often connected with the antibody response toward viral nucleotides and presents as morbilliform rash, maculopapular lesions, vesicular exanthems, urticaria and erythema multiforme; 2) systemic inflammation is associated with vasculitis and thrombosis which shows as peripheral cyanosis, livedo reticularis and chilblain-like lesions; 3) hypersensitivity reactions to drugs may occur more often during the pandemic due to the increased use of drugs and drug interactions, which can result in morbilliform rash, erythroderma, exanthematous pustulosis and anaphylaxis.