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[Severe Streptococcus pyogenes cutaneous infections]
1Service de pédiatrie, hôpital Louis-Mourier, 178, rue des Renouillers, 92701 Colombes, France. catherine.olivier@lmr.ap-hop-paris.fr
Insights
Streptococcus pyogenes causes severe skin infections like erysipela and necrotizing fasciitis (NF) in children. Early diagnosis and treatment, including antibiotics and surgery for NF, are crucial for survival.
Area of Science:
- Pediatric infectious diseases
- Bacteriology
- Dermatology
Context:
- Streptococcus pyogenes is a primary cause of severe pediatric cutaneous infections, including erysipela and necrotizing fasciitis (NF).
- Invasive S. pyogenes disease incidence is significant in children, with recent resurgences noted in North America.
- Skin lesions, such as varicella, serve as common entry points for these infections.
Purpose:
- To detail the clinical presentation, diagnosis, and management of Streptococcus pyogenes-associated skin infections in children.
- To highlight the differences between erysipela and necrotizing fasciitis (NF) and their diagnostic challenges.
- To emphasize the critical role of early intervention in improving outcomes for severe cutaneous infections.
Summary:
- Erysipela and NF present with distinct clinical features, though overlapping symptoms can complicate diagnosis.
- Necrotizing fasciitis (NF) is a surgical emergency requiring prompt surgical debridement alongside intravenous antibiotics.
- Microbiological diagnosis can be challenging, with varying detection rates across different sample types.
Impact:
- Timely diagnosis and appropriate management, particularly early surgery for NF, significantly reduce mortality and morbidity.
- Understanding the physiopathology and evolving virulence of S. pyogenes strains is key to combating invasive disease.
- This information is vital for pediatricians and infectious disease specialists managing severe skin infections in children.
Abstract:
Streptococcus pyogenes is the first bacteria encountered in severe cutaneous infections in children. They enclose erysipela (papillar derma concerned more than hypoderma, lymphatic involvement) and necrotising fasciitis NF (focus on fascia and muscles with extension to hypoderma and reticular derma; venous thrombosis; hypodermic and aponevrotic necrosis). A skin lesion is the entrance of infection: varicella lesions are a major factor of NF. In France, sporadic cases in children are observed. The annual incidence of S. pyogenes invasive diseases is 1/100,000 children under 5 years of age and 0.6/100,000 children under 15 years of age. In North America, resurgence has been notified during the past ten years with mortality and morbidity due to NF and toxic shock syndromes. Interaction between bacteria and host, natural reservoir, explains the physiopathology. During the past ten years, some serotypes have become more invasive and virulent. Any cutaneous lesion interrupt the dermal barrier. Bacterial wall, proteins M and adhesins permit colonisation. Four pyrogenic exotoxins are superantigens; some facilitate inflammation, tissular lesions and shock; other participate to bacterial extension. In young children, immune response is immature. Albeit causal link between non-steroids anti-inflammatory drugs and NF in varicella children was not clearly demonstrated, caution should be kept in mind. Diagnosis of erysipela is clinical: sudden appearance of an inflammatory zone, most often on legs, with high fever and pain; sometime peripheral surelevation, lymphangitis, adenopathia. Other aspects open discussion with NF. In NF are in favour, added to high fever, huge pain, erythema and oedema: rapid extension of lesions, cutaneous hypoesthesia appearance, gap between intense severe general status (toxic shock syndrome) and paucity of local signs. NF is a medico-surgical emergency. Early surgery with complete excision of necrotic tissues permit survival. Magnetic resonance is useful in subacute NF. Microbiological diagnosis is possible in 20 to 80% of cases, using combined methods. Blood cultures identify the bacteria in 5 to 20%, skin lesion samples in 30%. Local samples are less useful even with modern techniques. Therapeutic strategy depends on initial diagnosis. Intra-venous antibiotics are necessary: penicillin (G, A or M) is first line therapy. In erysipela, ten days allow a rapid cure without sequellae. In NF, antibiotics are associated with intensive care and surgery. A late diagnosis, a too late surgery explain 16 to 36% of deaths encountered.