Infections generally occur in intravenous drug abuse (IVDA) patients, most 
commonly affecting the spine and proximal joints. Numerous serious 
musculoskeletal complications of IVDA may involve the upper extremity, however. 
Soft-tissue complications in the upper extremity of IVDA patients include 
cellulitis, ulceration, abscess, pyomyositis, septic bursitis, tenosynovitis, 
and necrotizing fasciitis. Foreign bodies in soft tissue due to needle fragments 
are common findings. Primary bone and joint IVDA complications include 
osteomyelitis (acute and chronic) and septic arthritis. Other IVDA complications 
in the upper extremity affecting blood vessels and lymphatics include hematoma, 
arterial aneurysm and pseudoaneurysm, thrombosis, thrombophlebitis, "puffy hand" 
syndrome, and lymphadenopathy. These complications usually present as urgent 
issues requiring prompt and accurate evaluation in the acute setting. Diagnostic 
imaging not only aids in making the correct diagnosis but also permits precise 
definition of the location and extent of these abnormalities. We review the 
imaging findings and illustrate a wide range of disabling and even 
life-threatening complications affecting the upper extremity of IVDA patients 
that require early diagnosis for optimal outcome.