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.