Impetigo

Question 1

Define impetigo.

Answer 1

Impetigo is a superficial, contagious, blistering infection of the skin caused by the bacteria Staphylococcus aureus and Streptococcus pyogenes. It has two forms: non-bullous and bullous. Bullae are fluid-filled lesions of >0.5 cm in diameter.

Question 2

What is the aetiology of impetigo?

Answer 2

Impetigo is caused by Staphylococcus aureus (usual causative agent of the bullous type), Group A beta-haemolytic Streptococcus pyogenes (usual causative agent of the non-bullous type), or both.

Minor abrasions and skin lesions, associated with a wide variety of skin diseases, allow bacterial introduction into the skin.

Question 3

What are the risk factors for impetigo?

Answer 3

Presence of risk factors

Vesicles/bullae

Crusting

Question 4

Summarise the epidemiology of impetigo.

Answer 4

Impetigo is the most common bacterial skin infection in children worldwide, with a global prevalence of over 162 million.

Question 5

What are signs and symptoms of impetigo?

Answer 5

Vesicles/bullae

Crusting

Honeycomb crust

Erythema

Question 6

What are investigations for impetigo?

Answer 6

CLINICAL DIAGNOSIS

(baterial skin culture)

Question 7

What is the management for impetigo?

Answer 7

Oral antibiotics

Skin hygiene

Question 8

What are complications associated with impetigo?

Answer 8

Acute glomerulonephritis

Cellulitis

Osteomyelitis

Sepsis

Question 9

What is the prognosis of impetigo?

Answer 9

Patients typically need no follow-up unless they are:

Neonates: Impetigo can be more serious for neonates, with systemic and potentially life-threatening complications

Immunocompromised: May be at risk of poor response to treatment, with extension of infection into deeper tissues.