Explaining a neonatal pustular eruption and giving a safety-net — OSCE

Candidate instructions (8-minute station)

You are the paediatric registrar on the postnatal ward. A midwife has asked you to review a two-day-old term neonate who has developed scattered pale-yellow pustules on an erythematous base across the trunk and proximal limbs over the last few hours. The baby is feeding well, is afebrile, pink and warm, and behaves normally. The palms and soles are spared. The parents are very anxious that the baby has a serious infection and have asked to speak with a doctor. [2]

Your tasks are: [1]

1. Take a brief, focused history and confirm the wellness of the baby.
2. Explain the likely diagnosis and why no tests or treatment are needed.
3. Give a clear, specific safety-net.
4. Show the examiner you can recognise the features that would demand escalation. [1]

You have eight minutes. The examiner may ask you to explain your reasoning. [1]

Examiner briefing and marking domains

Information given to the candidate is accurate and complete. The lesion is erythema toxicum: a follicular pustule on an erythematous base, peaking at 24 to 48 hours, in a completely well neonate, sparing the palms and soles. [2]

Marking domains. [1]

• Clinical reasoning (communication of diagnosis). The candidate names erythema toxicum, explains that it is the commonest benign neonatal pustular eruption, and grounds the diagnosis in the morphology (follicular, erythematous base, sparing palms and soles), the timing (24 to 48 hours) and, above all, the wellness of the baby. The candidate may contrast it with transient neonatal pustular melanosis (present at birth, no erythematous base, involves palms and soles) to show differential command. [2] [3]
• Management and stewardship. The candidate explains that no tests or treatment are needed, that the eruption resolves spontaneously within days without scarring, and that a smear of the pustule would show eosinophils and be culture-negative if doubt ever arose. The candidate avoids unnecessary antibiotics and frames reassurance of a secure diagnosis as correct stewardship. [2]
• Safety-netting. The candidate gives a specific, written or clearly verbal safety-net: return immediately for fever, poor feeding, lethargy, or any change in the lesions such as new vesicles, spreading peeling or skin loss. [1]
• Recognition of danger. The candidate demonstrates they can step out of the reassure pathway when the picture changes: an ill or febrile neonate, clustered or disseminated vesicles (neonatal herpes simplex — full sepsis workup, HSV PCR and empiric intravenous aciclovir), and widespread tender erythema with peeling and spared mucosae (staphylococcal scalded skin syndrome — admit for intravenous anti-staphylococcal therapy and burn-style care). [6] [10]
• Communication and family-centred care. The candidate uses plain language, acknowledges the parents' anxiety, invites questions, and checks understanding. The closing message is that the baby is well, the eruption is benign and self-limiting, and the family knows exactly when to return.

Model answer the examiner expects to hear

"This is almost certainly erythema toxicum, the commonest of the normal newborn rashes. The spots are tiny pustules sitting on follicles with a small red base, they've appeared at the expected time around the second day of life, and — most importantly — your baby is feeding well, is a normal temperature, and is behaving normally. I've examined the palms and soles, which are spared, which is exactly what we see with erythema toxicum. [2]

"It needs no blood tests, no swabs and no creams — it settles on its own over the next few days and leaves no mark. If I were ever unsure, I could take a tiny smear of one pustule and look at it under the microscope, where erythema toxicum shows a particular cell called an eosinophil and grows no bacteria. [2]

"My safety-net for you is specific: please come back straight away if your baby develops a fever, feeds less well, becomes sleepy or lethargic, or if the spots change — for example if they turn into clear blisters or if the skin starts peeling in sheets. Those would be the signs that move us from reassurance into investigation. [1]

"The reason I'm confident is that your baby is well. The dangerous rashes I'd be watching for — like a herpes infection with clustered blisters on a sick, febrile baby, or a staphylococcal peeling rash — look different, and they come with a baby who is unwell. Because your baby is feeding and behaving normally, none of those apply today." [6] [10]