Derm Cases · Dermatology / Paediatrics / Infectious Disease
OSCE — fever and rash in a child: pattern recognition of viral exanthems
An 8-minute OSCE station on distinguishing measles, rubella, roseola, erythema infectiosum and hand-foot-mouth disease, identifying dangerous mimics (Kawasaki, meningococcaemia, SJS), public-health actions for measles, and supportive care with red-flag escalation.
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Study tools
Target exams
NEET-PGINICETUSMLEPLABMRCP
Prompt
An 8-minute OSCE station on distinguishing measles, rubella, roseola, erythema infectiosum and hand-foot-mouth disease, identifying dangerous mimics (Kawasaki, meningococcaemia, SJS), public-health actions for measles, and supportive care with red-flag escalation.
Brief (to candidate)
A 3-year-old presents with 4 days of fever, cough, coryza and conjunctivitis; today a cephalocaudal morbilliform rash appeared. Immunisation status is incomplete. A second vignette card shows alternatives (defervescence then rash; slapped cheek; oral–hand–foot vesicles). You have 8 minutes to identify the likely exanthem, exclude dangerous mimics, and plan isolation, supportive care and public-health steps.
[9]Candidate instructions
- Use prodrome + day of rash + distribution + enanthem to pattern-match classic viral exanthems.
- State the measles triad (3 Cs + Koplik) and notification/PEP actions.
- Differentiate roseola, fifth disease, rubella, HFMD.
- List dangerous mimics that must not be missed.
- Outline supportive care and specific red-flag escalations (vitamin A, pregnancy risk, aplastic crisis).
Examiner checklist (mark each domain / 10)
| Domain | Key actions expected |
|---|---|
| Measles pattern | Prodrome of cough, coryza, conjunctivitis; Koplik spots; rash day 3–4 spreading cephalocaudal; incomplete MMR → high suspicion; notifiable[1] |
| Key differentials | Roseola (HHV-6): high fever in relatively well infant, rash as fever defervesces; rubella: postauricular lymphadenopathy, milder illness, congenital risk; erythema infectiosum (B19): slapped cheek then lacy limbs; HFMD: oral ulcers + hand/foot vesicles (enterovirus)[2][3][5][7] |
| Dangerous mimics | Meningococcaemia, Kawasaki disease, drug morbilliform eruption / SJS, toxic shock, scarlet fever — toxicity, non-blanching purpura, prolonged fever, mucosal necrosis |
| Public health / measles Rx | Isolate airborne precautions; vitamin A for measles per age dosing in guideline settings; MMR within 72 h for susceptible contacts when indicated; notify public health[1] |
| Special risks | Parvovirus B19: pregnancy (fetal hydrops) and aplastic crisis in haemolytic disorders; varicella in pregnancy/neonate/immunocompromised (not primary vignette but if asked); HFMD neurological red flags |
| Supportive care | Hydration, antipyretics (avoid aspirin in viral illness with Reye risk discussion if relevant), return precautions for respiratory distress, encephalitis, poor feeding |
| Communication | Explain expected course of benign exanthems vs when to re-attend; vaccine catch-up counselling without blame |
Model key actions
- Identify classic measles from 3 Cs + Koplik + cephalocaudal timing and initiate isolation/notification ± vitamin A.[1]
- Rapidly distinguish roseola / fifth disease / rubella / HFMD by timing and morphology.[2][3][5][7]
- Explicitly exclude life-threatening non-viral mimics before discharging a “simple viral rash”.
Common errors
- Calling every morbilliform rash “measles” without prodrome/enanthem analysis.
- Discharging incomplete-immunisation measles without public-health notification.
- Missing pregnancy counselling for rubella/parvovirus exposures.
- Overlooking Kawasaki / meningococcal toxicity cues.
- Unnecessary antibiotics for classic self-limited viral exanthems.
References7ShowHide
- [1]Hübschen JM, Gouandjika-Vasilache I, Dina J. Measles. Lancet, 2022.PMID 35093206
- [2]Winter AK, Moss WJ. Rubella. Lancet, 2022.PMID 35367004
- [3]Leung AKC, Lam JM, Barankin B, et al. Erythema Infectiosum: A Narrative Review. Current Pediatric Reviews, 2024.PMID 37132144
- [5]Leung AK, Lam JM, Barankin B, et al. Roseola Infantum: An Updated Review. Current Pediatric Reviews, 2024.PMID 36411550
- [7]Leung AKC, Lam JM, Barankin B, et al. Hand, Foot, and Mouth Disease: A Narrative Review. Recent Advances in Inflammation & Allergy Drug Discovery, 2022.PMID 36284392
- [8]Lievano F, Galea SA, Thornton M, et al. Measles, mumps, and rubella virus vaccine (M-M-R II): a review of 32 years of clinical and postmarketing experience Vaccine, 2012.PMID 22959986
- [9]Su SB, Chang HL, Chen AK. Current Status of Mumps Virus Infection: Epidemiology, Pathogenesis, and Vaccine Int J Environ Res Public Health, 2020.PMID 32150969