RESUMEN
INTRODUCTION Actually, there are more than 200 different causes of unknown fever, it is necessary for the doctor to identify the most prevalent causes of unknown fever in our Clinical boar. PRESENTATION A 52-year-old male patient with no history of chronic diseases, which was received in the Emergency Service of the Hospital San Pablo, Coquimbo, on 02/03/20 began a clinical picture characterized by fever up to 39 ºC associated with diaphoresis, evaluated several times in primary health care without response to symptomatic treatment. He denies dyspnea, cough, sputum production, headache, muscle weakness, myalgia, fainting, decreased visual acuity, nausea, vomiting, chest pain, abdominal pain, diarrhea, constipation, altered bowel movements, weight loss, dysuria, bladder tenesmus, pain lumbar, skin lesions. As relevant information, the patient reports having taken amoxicillin/clavulanate for 2 days on his own account. DISCUSSION Physicians should be aware of the rare extent of an unusual presentation of knowledge origin fever, probably associated with Still disease, as well as medical options for treatment. The literature does not conclude on a gold standard for the method of approach. CONCLUSION In our case, the etiological agent that could cause Fever of unknown origin (FUO) was Sars cov-2 given the presence of elevated inflammatory factors and acute phase proteins and the presence of neutrophilic infiltration