Diagnosis and management of upper limb soft tissue infections

Soft tissue infections are common in the upper limb, particularly in the hand, which is exposed to the environment. They include entities that are diverse in their severity, their progression, and their frequency. However, what they have in common - if not managed correctly - is that they can have a major functional impact, amputation risk, or be life-threatening. The bacteria involved in upper limb infections are mainly Gram-positive cocci, but Gram-negative bacilli colonize bite wounds, which are common in the upper limb. From the most frequent and benign to the most serious, we distinguish: paronychia, infections without fluid collection such as bacterial dermohypodermitis (BDH), suppurative collections (abscesses) including pyogenic flexor tenosynovitis, and necrotizing soft tissue infections-necrotizing fasciitis (NSTI-NF). The clinical diagnosis is based on the presence of erythema, swelling, pain, and local heat. Lymphangitis or adenopathy are signs of regional spread. The appearance of skin necrosis or septic shock is suggestive of BNDH-FN. Laboratory tests will show elevated WBC, an increase in C-reactive protein for invasive infections, or even disturbances in the liver or kidney function, elevated lactate, which are signs of severity. Imaging examinations are mainly X-rays in the case of a wound, ultrasound or CT scan. Treatment of soft tissue infections of the upper limb is medical and surgical. Antibiotic therapy is sufficient in the case of BDH. Surgery is essential to drain any suppuration (pyogenic flexor tenosynovitis, abscess), or to widely excise the invaded tissues in NSTI-NF, in addition to antibiotic therapy that is subsequently adapted to microbiological findings. After the initial objective of eradicating the infection, the final objective is to allow the functional rehabilitation of the limb. The treatment of soft tissue infections in the upper limb is therefore often multidisciplinary, involving surgeons, and sometimes intensivists, infectiologists, and physiotherapists. Level of evidence >V: expert opinion.