Severe Infections of the Skin and Soft Tissues

Essentials

• Make a clinical diagnosis quickly.
• In necrotic skin and soft tissue infections, the patient should be transferred without delay to a hospital where surgical treatment can be carried out.
• Treatment in an intensive care unit is often required.
• The causative agent is searched for by blood cultures and by culture from possibly available tissue specimens.

Types of infection

Aetiology

• The most common causative agents in necrotizing skin and soft tissue infections are Streptococcus pyogenes and Staphylococcus aureus, but other microbes are encountered as well. Necrotizing infection may be caused by a mixed infection.
• Necrotizing fasciitis may originate from a minor laceration of the skin or without laceration of the skin. Underlying diseases (especially diabetes) may predispose to the infection. Often, however, there are no risk factors in the background.

Signs and symptoms

• Leucocytosis, increased CRP concentration, fever
• The symptoms of cellulitis include redness and heat of the skin as well as pain. The clinical picture resembles that of erysipelas, but the reddened skin area has more poorly defined borders than in erysipelas.
• The symptoms of necrotizing fasciitis include a rapid onset of swelling, redness and very severe pain. The clinical picture is often septic.
  • Fever is common, but can sometimes be absent.
  • The clinical picture is often consistent with critical illness, and features of septic shock may be present already in the initial stage.
  • The skin may blister and discolour to a purplish red. The skin manifestations may be misleadingly slight or completely absent. The subcutaneous tissue becomes gangrenous.
  • Signs of septic complications are often already seen in the initial blood tests: increased creatinine and aminotransferase concentrations, thrombocytopenia. Creatine kinase (CK) if often increased due to tissue necrosis.
• In gas gangrene, the necrotic wound becomes swollen and painful with palpable crepitus.

Treatment Interventions for Cellulitis and Erysipelas

• Cellulitis with mild symptoms may be treated with penicillin, but if the treatment response is not rapid, the medication should be changed for cefuroxime, clindamycin or anti-staphylococcal penicillin.
• The most important treatment of necrotizing skin and soft tissue infection is urgent surgical debridement. All infected tissue and the overlying skin must be removed.
• Necrotizing skin and soft tissue infection is treated with the combination of a beta-lactam antimicrobial drug (penicillin and other antibacterial drugs with beta-lactam structure) and clindamycin.
  • Empirical treatment is often started with a broad spectrum, e.g. by using carbapenems or piperacillin-tazobactam in combination with clindamycin. Treatment may become targeted based on microbiological findings.
  • The significance of hyperbaric oxygen therapy Hyperbaric Oxygen Therapy (HBOT) as an adjunct to other treatment is unclear. Possible transportation to hyperbaric oxygen therapy site must not delay radical surgical treatment.
  • The status of intravenous immunoglobulin therapy (IVIG) is unclear.

Prevention

• Appropriate treatment of skin lacerations