Clues		Possible diagnoses
Historical
Exposures
	Fresh water exposure	Leptospirosis
	Living conditions (e.g., homeless shelter)	Tuberculosis
	Occupational exposures/sick contacts (e.g., with hospitalized patients, children)	Cytomegalovirus, Epstein-Barr virus, tuberculosis
	Pets, wild animals	Brucellosis
	Recent travel, especially to areas with endemic diseases (domestic and abroad)	Region specific (e.g., Q fever for parts of Europe)
Family history
	Hereditary febrile conditions	Familial Mediterranean fever
Medical history
	Abdominal disorders	Alcoholic hepatitis, cirrhosis, Crohn disease
	History of transfusions	Hepatitis B or C, HIV
	Malignancy	Metastatic disease
	Psychiatric illness	Factitious fever
	Recent hospitalization	Nosocomial infection
Risk-taking behaviors
	Intravenous drug abuse	Abscess, endocarditis, osteomyelitis
	Sexually transmitted infection exposure	HIV
Surgical history
	Presence of prostheses	Osteomyelitis
Physical
Characteristic rashes (e.g., erythema multiforme, petechiae)		Adenovirus, herpes simplex virus, HIV, meningococcemia, tick-borne illness
Conjunctivitis or uveitis		Adult Still disease, leptospirosis, systemic lupus erythematosus
Hepato- or splenomegaly; palpable abdominal masses		Alcoholic liver disease, carcinoma, cytomegalovirus, Epstein-Barr virus, leukemia, lymphoma
Joint swelling or pain with movement		Inflammatory bowel disease, Lyme disease, systemic lupus erythematosus
Lymphadenopathy		Cat-scratch disease, cytomegalovirus, Epstein-Barr virus, HIV