Best treatment of impetigo 2024

Impetigo Overview

Etiology and Pathogenesis
Impetigo, the most common skin infection in children worldwide, presents in two forms: nonbullous and bullous.

– Nonbullous Impetigo:

Predominantly caused by *Staphylococcus aureus* though group A β-hemolytic streptococci (GABHS) can also be involved. Staphylococci usually spread from the nose to the skin, while GABHS colonize the skin about 10 days before lesions appear.
– Bullous Impetigo: Exclusively caused by *S. aureus* strains producing exfoliative toxins (ETA, ETB, ETD), which target desmoglein 1, leading to superficial epidermal blistering.

Clinical Manifestations
– Nonbullous : Accounts for over 70% of cases, usually starting as vesicles or pustules that quickly form honey-colored crusts, primarily on the face and extremities. Lesions are typically non-painful, mildly itchy, and often accompanied by regional adenopathy and leukocytosis.
– Bullous : Primarily affects infants and young children, with flaccid bullae forming on the face, buttocks, trunk, perineum, and extremities. Bullae rupture easily, leaving shallow erosions without surrounding erythema or significant adenopathy.
Differential Diagnosis
– Nonbullous Impetigo: Consider herpes simplex, varicella-zoster, tinea corporis, arthropod bites, and scabies.
– Bullous Impetigo: In neonates, consider epidermolysis bullosa, bullous mastocytosis, herpetic infection, and early staphylococcal scalded skin syndrome. In older children, consider allergic contact dermatitis, burns, erythema multiforme, linear immunoglobulin A dermatosis, pemphigus, and bullous pemphigoid.

Complications
– Rare complications include bacteremia, osteomyelitis, septic arthritis, pneumonia, and septicemia.
– Nonbullous Impetigo: Cellulitis occurs in up to 10% of cases. Poststreptococcal glomerulonephritis may follow GABHS infection, particularly in children aged 3-7 years, with a latency of 18-21 days post-infection. Rheumatic fever does not result from impetigo.

Treatment
– Topical Therapy: Mupirocin 2% or retapamulin 1%, applied 2-3 times daily for 10-14 days, for localized *S. aureus* infections.
– Systemic Therapy: Oral antibiotics such as cephalexin (25-50 mg/kg/day in 3-4 divided doses for 7 days) for streptococcal or widespread staphylococcal infections, or when lesions are near the mouth or show deep involvement. If MRSA is suspected, use clindamycin, doxycycline, or sulfamethoxazole-trimethoprim. Compliance issues can be addressed with a single dose of benzathine benzylpenicillin IM.

No substantial evidence suggests a longer treatment duration is more effective, and short-course antibiotics can be as effective as longer courses.