Fever

CLINICAL DIAGNOSIS MANUAL

Fever is a temporary increase in body temperature, usually due to illness. It is one of the most common signs of an infection or other underlying condition. Fever may be accompanied by other symptoms depending on its cause.

Pathology	Diagnosis of Suspicion	Diagnosis of Confirmation
Infections	Symptoms of fever accompanied by specific signs of infection (pain, redness, pus).	Blood, urine, stool cultures, or site-specific cultures according to symptoms; imaging tests if necessary.
Thrombosis	Fever with localised pain, redness, swelling in a limb.	Doppler ultrasound to detect clots in blood vessels.
Tissue Necrosis	Fever with a history of trauma, surgery, or evidence of gangrenous injury.	Imaging studies to visualise areas of necrosis; biopsy in doubtful cases.
Neoplasia	Fever of unknown origin, weight loss, night sweats (especially in lymphomas).	Imaging studies such as CT, MRI, or PET; tissue biopsy for histological diagnosis.
Autoimmune Diseases	Fever accompanied by systemic symptoms such as rash, arthralgia, fatigue.	Specific antibody tests (ANA, anti-dsDNA), complement levels, elevated CRP and ESR.
Drugs	Fever appearing after the administration of a new medication without another apparent cause.	Review of medical and medication history; discontinuation of the suspected drug with resolution of fever.