Impetigo — Clinical Case (Wikimedia Commons)

Diagnosis: Impetigo

Skin lesions that proved to be impetigo. Impetigo is usually caused by Group A Streptococcus sp. or Staphylococcus aureus bacteria. Note how the maculopapular lesions resemble syphilis, which is cause. Clinical photograph sourced from Wikimedia Commons (Public domain). Attribution: US Gov.

Clinical Presentation

Non-bullous: begins as erythematous macule → vesicle/pustule → characteristic golden/honey-colored crusts. Bullous: flaccid bullae that rupture leaving shallow erosions with collarette of scale. Perioral and perinasal distribution common.

Clinical History

More common in warm, humid climates. Risk factors: crowding, poor hygiene, minor skin trauma, pre-existing dermatoses (eczema, scabies). Highly contagious — outbreaks in schools and daycare. MRSA increasingly common cause.

Treatment

Limited: topical mupirocin or retapamulin. Extensive/bullous: oral antibiotics (cephalexin, dicloxacillin; TMP-SMX or doxycycline if MRSA suspected). Wound care: gentle debridement of crusts. Keep lesions covered to prevent spread.

Differential Diagnosis

Herpes simplex, Contact dermatitis, Tinea corporis, Bullous pemphigoid (bullous form), Eczema herpeticum, Varicella

Key Learnings

Post-streptococcal glomerulonephritis is a potential complication (monitor urinalysis if GAS confirmed). Bullous impetigo is caused by S. aureus exfoliative toxins. Distinguish from eczema herpeticum which requires antiviral therapy.

Tags: impetigo, bacterial, infection, staphylococcal, pediatric