patient under guardianship or curator patient with plausible alternate diagnosis ards evolving for more than 4 days contraindication to the hydroxychloroquine : known allergy or intolerance to the hydroxychloroquine or to one of the excipients of the drug, in particular to lactose; documented qt prolongation and / or known risk factors for qt prolongation (including ongoing treatment with citalopram, escitalopram, hydroxyzine, domperidone or piperaquine), retinopathies contraindication to dexamethasone: known allergy or intolerance to dexamethasone or to one of the excipients of the drug, another evolving virosis (hepatitis, herpes, chickenpox, shingles), severe coagulation disorder uncontrolled septic shock untreated active infection or treated less than 24 hours long-term patient treated with corticosteroids (> 20 mg / day) or hydroxychloroquine immunocompromised patients: aids, bone marrow or solid organ transplant recipients pregnant women glucose-6-phosphate dehydrogenase (g6pd) deficiency

patient under guardianship or curator patient with plausible alternate diagnosis ards evolving for more than 4 days contraindication to the hydroxychloroquine : known allergy or intolerance to the hydroxychloroquine or to one of the excipients of the drug, in particular to lactose; documented qt prolongation and / or known risk factors for qt prolongation (including ongoing treatment with citalopram, escitalopram, hydroxyzine, domperidone or piperaquine), retinopathies contraindication to dexamethasone: known allergy or intolerance to dexamethasone or to one of the excipients of the drug, another evolving virosis (hepatitis, herpes, chickenpox, shingles), severe coagulation disorder uncontrolled septic shock untreated active infection or treated less than 24 hours long-term patient treated with corticosteroids (> 20 mg / day) or hydroxychloroquine immunocompromised patients: aids, bone marrow or solid organ transplant recipients pregnant women glucose-6-phosphate dehydrogenase (g6pd) deficiency

1. patient under guardianship or curator 2. patient with plausible alternate diagnosis 3. ards evolving for more than 4 days 4. contraindication to the hydroxychloroquine : known allergy or intolerance to the hydroxychloroquine or to one of the excipients of the drug, in particular to lactose; documented qt prolongation and / or known risk factors for qt prolongation (including ongoing treatment with citalopram, escitalopram, hydroxyzine, domperidone or piperaquine), retinopathies 5. contraindication to dexamethasone: known allergy or intolerance to dexamethasone or to one of the excipients of the drug, another evolving virosis (hepatitis, herpes, chickenpox, shingles), severe coagulation disorder 6. uncontrolled septic shock 7. untreated active infection or treated less than 24 hours 8. long-term patient treated with corticosteroids (> 20 mg / day) or hydroxychloroquine 9. immunocompromised patients: aids, bone marrow or solid organ transplant recipients 10. pregnant women 11. glucose-6-phosphate dehydrogenase (g6pd) deficiency

1. patient under guardianship or curator 2. patient with plausible alternate diagnosis 3. ards evolving for more than 4 days 4. contraindication to the hydroxychloroquine : known allergy or intolerance to the hydroxychloroquine or to one of the excipients of the drug, in particular to lactose; documented qt prolongation and / or known risk factors for qt prolongation (including ongoing treatment with citalopram, escitalopram, hydroxyzine, domperidone or piperaquine), retinopathies 5. contraindication to dexamethasone: known allergy or intolerance to dexamethasone or to one of the excipients of the drug, another evolving virosis (hepatitis, herpes, chickenpox, shingles), severe coagulation disorder 6. uncontrolled septic shock 7. untreated active infection or treated less than 24 hours 8. long-term patient treated with corticosteroids (> 20 mg / day) or hydroxychloroquine 9. immunocompromised patients: aids, bone marrow or solid organ transplant recipients 10. pregnant women 11. glucose-6-phosphate dehydrogenase (g6pd) deficiency