Organism

The most common causes of hand infection include:

• Staphyloococcus spp. - occurs in up to two thirds of hand infections
• Streptococcus spp. - 10-15% *
• coliforms
• Pasteurella
• Clostridia
• Pseudomonas
• Bacteroides

Less commonly:

• virus
• fungi
• mycobacteria

Notes:

• * incidence of Streptococcus in hand infections remained as low as 10-15% for several decades - however, more recently there has been a noticeable increase in infections caused by Streptococcus
• daily practice indicates that in the vast majority of cases the infection is of mixed bacterial origin
• with respect to bites ( human, dog or cat bites) the danger of infection is very high - also the organisms of the oral cavity are special, such as the Pasteurella multocida and Eikenella corrodens (both are sensitive to crystalline penicillin)
• if a hand infection occurs in a drug abuse patient then dorsal abscesses are very common and in advanced cases are often combined with involvement of the joints - infections in these cases may include organisms such as Serratia and Pseudomonas
• aquatic and farm exposure may result in uncommon infections such as Mycobacteria tendon sheath infections

Reference:

1. Flügel, Margita & Hankiss, J. Primary Pyogenic Infections of the Hand: Anatomy, Pathology and Therapy . European Surgery 2003;35 (3): 137-142.