Discussion
COVID-19 and dengue have a spectrum of disease with overlap in clinical manifestations. Here, we reported a confirmed case of COVID-19 along with coinfection by dengue. Hemoptysis was the initial and only indication of COVID-19 infection in this patient with dengue fever, which was atypical. Hemoptysis can range from mild to severe from a smear of blood in the sputum to a life-threatening hemorrhage (6). The majority of dengue infection patients have bleeding, shock, organ failure, and metabolic acidosis as a result of their illness. It is unusual for lower respiratory tract to be involved. Dengue fever is a potentially fatal disease characterized by pulmonary capillaritis, which causes diffuse alveolar hemorrhage (DAH) which can lead to hemoptysis (7). It may be the symptom of a number of diseases such as tuberculosis, malignancy, bronchiectasis, and pneumonia or other conditions (8). This patient had no anticoagulated or antiplatelet drugs history previously. As she had no long-term history of low-grade fever, weight loss or cough, tuberculosis test for hemoptysis was not performed. However unusual symptoms, such as hemoptysis or atypical CT findings, may emerge in certain individuals, posing a significant challenge to the epidemic’s management (9). In our case the patients had hemoptysis with other accompanying symptoms. In a recent study, hemoptysis was found to be 1.45-2.7 percent in the case of dengue fever, whereas in COVID-19 it was about 13 percent (10, 11). COVID-19 characteristics such as spike and nucleocapsid proteins activate the host’s immune system, causing the virus to be eliminated. In the acute stage, these viral antigens can be identified by B cells or conveyed to T cells via MHC complexes, leading in antibody formation, enhanced cytokine secretion, and cytolytic activity (12). Increased blood levels of IL-2, IL-6, IL-10, and IFN- are signs of excessive cytokine production in severe instances of COVID-19 (13). High cytokine release and possible ACE2 expression downregulation in severe COVID-19 can not only promote a hypercoagulable condition separately, but also bilaterally boost each other’s pro-thrombotic activities (13). Coagulation system activation is common in critically ill COVID-19 patients (14). Hemoptysis may be an initial symptom of venous thromboembolism (VTE), and there is a case presenting with hemoptysis owing to pulmonary emboli associated with COVID-19 (3). In our patients, hypercoagulability values such as D-dimer and ferritin were within normal limits, and no VTE was observed in the radiological examination. Alveolar hemorrhage is a potential COVID-19 consequence in this case. Dengue is not known to cause lung alterations, and imaging results are likely due to increased vascular permeability. Dengue fever, hemoptysis, especially diffuse pulmonary infiltration needs to be evaluated in the differential diagnosis. Bilateral regions of ground-glass opacity or consolidation, as well as bilateral pleural effusions, are the most prevalent radiographic findings in dengue that also seen COVID-19 pneumonia (10). The key take away message from this case is that a lack of knowledge of hemoptysis as a potential COVID-19 clinical manifestation has resulted in initial misdiagnosis and delayed diagnosis. When dealing with any patient arriving to the hospital in this pandemic situation with a history of hemoptysis, COVID-19 should be evaluated in the differential diagnosis list, even if the other characteristic clinical symptoms of COVID-19, such as fever, dry cough, myalgia, and shortness of breath are missing. COVID-19 is a novel illness with many unknown features, unusual presentations such as severe hemoptysis should also arouse concern regarding the diagnosis of COVID-19, particularly in pandemic situations in dengue endemic settings.