Fever is a common patient presentation with a very large number of differentials. Probable diagnoses on this clinical mind map are chunked based upon systems/organs involved in the underlying pathophysiologic process which gave rise to fever. Organs within a system generally produce a similar constellation of symptoms and can therefore be chunked in such a fashion. For example, patients with pneumonia, bronchitis, upper respiratory infection, and bronchiolitis may all present with cough, while patients with diverticulitis, cholecystitis, and appendicitis share abdominal pain as a common symptom. For this reason, in addition to the duration of fever which divides the differentials into two broad categories, the constellation of symptoms for individual systems/organs are considered high yield questions as well. These questions help narrow the differentials and are listed prior to probable diagnoses in the clinical mind map. Almost any severe infection can give rise to urgent/emergent urgent/emergent situations although some infections are more likely than others to do so. Such urgent/emergent situations are reflected in abnormal vital signs, altered mental status, signs of end organ failure, and a patient’s appearance of distress.

Weighing and removing anchor bias involves a clinician asking all questions pertinent to the organs/systems which seem to be the focus of infection, and then asking additional questions to make sure an additional system/organ is not overlooked. If a fever is of chronic duration, a clinician can adopt a similar method. In cases of chronic fever, a wide range of underlying pathophysiologic processes may be at play. The knowledge of risk factors and epidemiological data helps point a clinician to one of the categories for identifying the source of fever. Therefore, a clinician must ask questions on those lines, such as recent travel, possible exposure to certain infections, symptoms suggestive of connective tissue diseases, and risk factors for certain malignancies. A detailed physical exam for the system involved, a brief physical exam for other systems, and diagnostic tests help a clinician arrive at the final diagnosis.

Although several diagnoses are listed on this clinical mind map, certain infections/diagnoses are omitted due to space constraints, but should be considered if clinically indicated.