Explaining impetigo, school exclusion and household care — OSCE

Candidate instructions (8-minute station)

You are the paediatric registrar in the clinic. A 4-year-old child has crusted, weeping sores spreading from the nose across the cheek over the last five days. The child is otherwise well and afebrile. A younger sibling has developed a similar sore on the chin, and the child has underlying atopic dermatitis. The family asks whether the child can stay at school. [1]

Your tasks are: [1]

1. Explain the diagnosis of impetigo and what the illness will look like over the coming week, in plain language. [1]
2. Explain the five-day topical treatment and the school-exclusion plan. [1]
3. Explain why the sibling needs assessment, and what a decolonisation strategy means for the household if sores keep coming back. [7]
4. Tell the family what late features to watch for over the next few weeks, and why controlling the atopic dermatitis matters. [2]

You are not expected to take a full household swabbing history yourself or to prescribe oral antibiotics here without review — the sibling needs assessment in their own right. [8]

Examiner prompt to the actor (parent)

"But it is just a sore — does she really have to stay home from school? And her little brother has one on his chin now, so is the cream enough for both of them, or do they need something stronger? I had no idea a skin sore could be dangerous." [7]

Marking domains

• Frame and explanation (3): explains impetigo as a common, contagious but very treatable bacterial skin infection in plain, reassuring language; names that the child is well and not in danger now; sets the expectation that the cream works over a few days and the crust heals without scarring. [1]
• Treatment and exclusion plan (3): explains clearly the five-day topical course (hydrogen peroxide 1% or fusidic acid 2%, applied two to three times daily), gentle cleansing and hand hygiene, and the school-exclusion rule — until the lesions are dry, crusted or healed, or 24 hours into effective treatment — because the danger is passing it to other children. [1]
• Sibling and household care (2): explains that the sibling's sore needs its own assessment and treatment, and that if sores keep coming back the family may need a decolonisation strategy — bleach baths or antiseptic washes and a nasal ointment for everyone in the household — because the sore spreads between family members. [7]
• Late features and the portal of entry (2): tells the family to watch over the next one to three weeks for puffy or swollen eyes, dark or cola-coloured urine, or reduced urine output, which can signal a kidney complication after a strep sore; and explains that controlling the eczema is what prevents the next sore, because the broken skin is how the bacteria get in. [2]

Model answer — the explanatory script

"Thank you for bringing her in. What you are describing is impetigo — it is the most common bacterial skin infection in children, and the good news is it is very treatable. Those honey-coloured, weepy crusts around the nose and mouth are exactly what it looks like, and because she is otherwise well, eating and playing and has no fever, she is not in any danger. With the right cream it settles over a few days, and it heals without leaving a scar." [1]

"Three things I want to talk through — the treatment, the school question, and what to watch for over the next few weeks." [1]

"First, the treatment. I will give you a cream to put on the sores two to three times a day for five days. Before each application, gently wash the area with soap and water and pat it dry. Wash her hands often and keep her nails short, because the sore spreads by scratching and touching. The cream is enough for her because the sores are limited and she is well — she does not need an oral antibiotic at this stage." [1]

"Second, school. I am afraid she does need to stay home until the sores have dried up and crusted over, or until she has had 24 hours of the cream. The reason is not that she is unwell — it is that impetigo is quite contagious between children, and we want to stop it spreading to her classmates. With the cream and the exclusion it should settle quickly." [1]

"Third, her brother. Because he now has a sore on his chin, he needs to be seen and treated too — the cream may well be enough for him as well, but I would like him assessed in his own right rather than just sharing hers. And if these sores keep coming back in your household, which they sometimes do, we would think about a different approach — not just treating the sore but treating the bacteria that live in the nose and on the skin of the whole family, with a special wash or bath and a nasal ointment for everyone at the same time. That is called decolonisation, and it is what breaks the cycle when sores keep recurring." [7]

"Finally, what to watch for. Over the next one to three weeks, the thing I want you to look out for is her eyes becoming puffy or swollen, her urine turning dark, like cola or strong tea, or her weeing less than usual. That can be a sign of a kidney inflammation that sometimes follows a sore caused by a strep germ — it is not common, but it is important, and if you see it, bring her straight back. We would check her blood pressure and her urine. And the last piece of the puzzle is her eczema. The reason she got the sore in the first place is that her eczema leaves little cracks in the skin that let the bacteria in, so the best way to prevent the next sore is to keep the eczema well moisturised and under control. We will sort the sore today, and then we will work on the skin underneath." [2]