Endocarditis differential diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Maliha Shakil, M.D. [2]

Overview

Endocarditis must be differentiated from other causes of a fever of unknown origin (FUO) such as pulmonary embolism, deep vein thrombosis, lymphoma, drug fever, cotton fever, and disseminated granulomatoses.

Differential Diagnosis

Endocarditis must be differentiated from other causes of a fever of unknown origin such as:

• Lymphoma
• Pulmonary embolism
• Deep vein thrombosis
• Drug fever
• Cotton fever
• Disseminated granulomatoses such as tuberculosis, histoplasmosis, coccidioidomycosis, blastomycosis, and sarcoidosis

Drug Fever

A drug fever will resolve with discontinuation of the offending agent. There may be elevated urine eosinophils and a peripheral eosinophilia as well.

Cotton Fever

The symptoms of cotton fever resemble those of sepsis and patients may be initially misdiagnosed upon admission to a hospital. However sepsis is a serious medical condition which can lead to death, whereas cotton fever, if left alone, will usually resolve itself spontaneously within 12-24 hours. Symptoms usually appear with 10-20 minutes after injection and in addition to fever may include headaches, malaise, chills, nausea and tachycardia. The fever itself usually reaches 38.5 - 40.3°C (101 - 105°F) within the first hour.

Table 1; Differentiating psittacosis from other diseases

Clinical feature	Cough	Sputum	Dyspnea	Sore throat	Headache	Confusion	Diarrhea	Chest radiograph changes	Hyponatremia	Leukopenia	Abnormal Liver function tests	Treatment
Psittacosis	++	-	+	-	+++	+	Minimal	No changes seen	-	+	-	Doxycycline
C.pneumoniae pneumonia	+	+	+	+++	++	+	-	Minimal changes observed	-	-	-	Doxycycline, Azithromycin
M. pneumoniae pneumonia	++	++	++	-	-	-	-	Bronchial wall thickening Centrilobular nodules Ground-glass attenuation Consolidation	-	-	+	Doxycycline
L. Pneumophila infection	+	+++	+++	-	+	++	+	Often Multifocal	++	+	++	Doxycycline
Influenza	++	++	++	++	++	+/-	+/-	Bi-basal air-space opacities Perihilar reticular and alveolar infiltrates	-	-	-	zanamivir, oseltamivir,
Endocarditis	++	++	+	-	-	-	-	Hazy opacities at lung bases bilaterally	-	+/-	+/-	Vancomycin
Coxiella burnetii infection	++	-	+	+/-	-	+/-	Minimal	Segmental or lobar opacification Occasional pleural effusions	-	+/-	=/-	Doxycycline
Leptospirosis	++	+	++	+	+	++	-	Multiple ill-defined nodules in both lungs.	+++			Doxycycline, azithromycin, amoxicillin
Brucellosis	++	-	+	-	++	+	-	Soft miliary mottling Parenchymal nodules Consolidation Chronic diffuse changes Hilar or paratracheal lymphadenopathy Pneumothorax.	-/+	+/-	+/-	Doxycycline, rifampin

Key;

+, occurs in some cases

++, occurs in many cases,

+++, occurs frequently