Can a person with immunosuppression due to hydroxychloroquine remain afebrile during influenza (flu) or Coronavirus Disease 2019 (COVID-19) infection, despite experiencing symptoms like chills and body aches?

Immunosuppression from Hydroxychloroquine and Fever Response in Flu or COVID-19

Patients taking hydroxychloroquine for immunosuppression can remain afebrile during flu or COVID-19 infections despite experiencing other symptoms like chills and body aches. 1

Hydroxychloroquine's Immunomodulatory Effects

• Hydroxychloroquine is primarily used as an antimalarial drug but is also prescribed for various rheumatic and autoimmune conditions due to its immunomodulatory properties 1
• It has an immunomodulatory rather than strongly immunosuppressive effect, which means it modifies immune responses without completely suppressing the immune system 1
• The drug works by interfering with lysosomal activity and inhibiting antigen presentation, which affects the immune response 1

Fever Response in Patients on Hydroxychloroquine

• Patients on hydroxychloroquine can experience altered inflammatory responses to infections, which may affect classic fever presentation 1
• The immunomodulatory effects of hydroxychloroquine can potentially dampen the inflammatory cytokine response that typically triggers fever during infections 1
• Despite the absence of fever, other symptoms like chills and body aches may still occur as they can be mediated through different inflammatory pathways 1

COVID-19 and Influenza Presentation in Immunomodulated Patients

• Patients with altered immune responses due to medications like hydroxychloroquine may present with atypical symptoms during viral infections 1
• The absence of fever does not rule out COVID-19 or influenza infection, especially in patients taking immunomodulatory drugs 1
• Chills and body aches without fever can still be indicative of viral infection in these patients 1

Clinical Implications

• Healthcare providers should maintain a high index of suspicion for COVID-19 or influenza in patients on hydroxychloroquine who present with respiratory or systemic symptoms, even without fever 1
• Testing for COVID-19 or influenza should be considered in these patients based on symptoms like chills and body aches, regardless of temperature 1
• The absence of fever should not delay diagnosis or appropriate management of these infections in immunomodulated patients 1

Important Considerations

• Hydroxychloroquine itself has been studied as a potential treatment for COVID-19, but large randomized controlled trials have shown no benefit for treatment or prevention 1, 2
• The European Respiratory Society strongly recommends against using hydroxychloroquine for COVID-19 treatment due to lack of efficacy and potential adverse effects 1
• Patients already taking hydroxychloroquine for rheumatic diseases should not discontinue it during the pandemic, as it may have a protective effect against severe COVID-19 and is important for managing their underlying condition 1

Monitoring Recommendations

• Patients on hydroxychloroquine who develop symptoms consistent with viral infections should be closely monitored, even in the absence of fever 1
• Healthcare providers should educate patients about potential atypical presentations of infections and when to seek medical attention 1
• Consider more frequent monitoring or lower thresholds for testing in these patients during influenza or COVID-19 outbreaks 1