Differential Diagnosis of Fever in Intravenous Drug Abusers

Fever is a major problem in intravenous drug users.The most common causes are cellulitis and pneumonia. Skin infections (the most common cause of admission, which is most commonly caused by S. aureus and B-hemolytic streptococci), endocarditis (Staph aureus is the dominant causative organsim, usually leading to fever and pulmonary emboli and poor response to antibiotic therapy), bacteremia, peripheral vascular infections(such as femoral mycotic aneurysm), bone and joint infections(the most commonly involved joint and bone are knee and lumbosacral spine), pulmonary infections and noninfectious insults (which are very common and include septic emboli, TB, community acquired pneumonia and lung abcess), hepatitis, CNS involvement (which accounts for the most serious complications and usually is a result of endocardtis), AIDS (about 25% of AIDS cases are IV drug abusers), splenic abcess, endophtalmitis(usually due to candidia infection) are causes of fever in infectious group. Non - infectious causes including: Cotton-fever, Rhabdomyolysis and herion hypersensitivity.