Makindo Medical Notes

Related Subjects: |Cellulitis |Impetigo |Pyoderma gangrenosum |Pemphigus Vulgaris |Toxic Epidermal Necrolysis |Stevens-Johnson Syndrome |Necrotising fasciitis |Gas Gangrene (Clostridium perfringens) |Anatomy of Skin |Skin Pathology and lesions |Skin and soft tissue and bone infections

About

• Impetigo is a highly contagious bacterial skin infection
• Superficial infection of epidermis
• Affecting all ages but most commonly seen in school-aged children.
• Risks are hot conditions, poor hygiene, and crowding

Aetiology

• Typically caused by group A streptococcus, S. aureus, maybe MRSA
• Staphylococcus aureus (mainly responsible for impetigo)
• Streptococcus pyogenes (another common cause)

Clinical Features

• “Honey-colored,” crusted lesion
• Skin infection causing blisters and sores
• Typically affects the face, especially around the mouth
• Occasionally affects the arms and legs
• Bullous impetigo: Rapidly spreading blistering
• Non-bullous impetigo: Characterized by yellow-brown exudate that forms a golden crust

Differential Diagnoses

• Herpes simplex virus (HSV) infections
• Chickenpox (Varicella zoster)
• Contact dermatitis
• Insect bites with secondary bacterial infection

Investigations

• Swabs of the affected area for bacterial culture to identify the causative organism
• Gram stain of exudate from lesions
• Polymerase chain reaction (PCR) testing for confirmation in some cases

Management

Topical antibiotics for mild disease and Systemic antibiotics for more severe disease

• Antibacterial swabs and washes to help cleanse the affected skin
• Isolation measures to prevent the spread of infection, especially in schools or daycares
• Mild cases: Topical Mupirocin or Fusidic acid to treat localized infections
• Systemic treatment: Penicillin or Cephalosporins for more widespread infections or for resistant strains
• Surgical assessment and debridement in severe cases, especially if there is a large area of infection or complications

References

• National Institute for Health and Care Excellence (NICE) guidelines on impetigo
• Centers for Disease Control and Prevention (CDC) - Impetigo overview
• DermNet NZ - Impetigo treatment and diagnosis

Revisions

• Updated clinical features and management recommendations based on recent guidelines
• Additional differential diagnoses added to guide clinicians in distinguishing from similar skin conditions