OSCE — assessment of moderate-to-severe atopic dermatitis with infection risk · MBBS OSCE

Brief (to candidate)

A 9-year-old boy has chronic itchy flexural rash since infancy, worse at night, with recent weeping and fever after a cluster of monomorphic punched-out erosions around the neck. His mother reports asthma and dry skin. You have 8 minutes to assess severity, exclude emergency infection, and outline stepwise management. ^[1]

Candidate instructions

Take a focused history (onset, distribution, triggers, atopy, sleep, school impact, prior treatments). ^[1]
Examine skin morphology and distribution; state when you would examine eyes/lymph nodes.
Grade severity and name validated scores (EASI / SCORAD / IGA / DLQI).
Identify red flags (eczema herpeticum, erythroderma, secondary bacterial infection).
Outline stepwise management (emollients → topicals → phototherapy/systemic/biologic) with safety checks.
Give safety-net and follow-up advice.

Examiner checklist (mark each domain / 10)

Domain	Key actions expected
Recognition	Poorly demarcated erythematous, lichenified flexural patches; itch–scratch cycle; age-dependent distribution (infant face/extensors → childhood flexures)^[1]
History & atopy	Personal/family atopy (asthma, rhinitis, food allergy); filaggrin/barrier concept; triggers (irritants, infection, climate)^[4]
Severity	Names EASI / SCORAD / IGA and impact (sleep, school); distinguishes mild vs moderate-to-severe needing systemic step-up
Red flags	Eczema herpeticum (monomorphic punched-out erosions + fever) — urgent antivirals/admission; also erythroderma, severe secondary infection
Stepwise Rx	Daily emollients + soap substitute; topical corticosteroid (appropriate potency by site) ± calcineurin inhibitor for face/folds; wet wraps for flares; antibiotic only if infected^[2]
Systemic / biologic	For refractory moderate–severe disease: phototherapy or systemic (e.g. cyclosporine short course) / dupilumab (IL-4Rα); pre-treatment infection screen and vaccination planning as appropriate^[3]
Communication	Explains chronic relapsing course; steroid phobia counselling; return if fever, punched-out erosions, or rapid worsening

Model key actions

Recognise chronic flexural eczema with barrier/type-2 inflammation framing.^[1]
Exclude eczema herpeticum in this febrile, monomorphic-erosion presentation — treat as emergency (systemic aciclovir/admission pathway). ^[1]
Ladder: emollient foundation → topical anti-inflammatory → phototherapy/systemic → dupilumab for refractory disease.^[2]^[3]
Address sleep, school, and parental steroid concerns; plan review after flare control.

Common errors

Missing eczema herpeticum and treating as bacterial impetigo alone. ^[1]
Systemic corticosteroids as long-term control (rebound/side effects).^[12]
Antibiotic or topical steroid without emollient foundation.
Using potent steroids long-term on face/folds without TCI option.
Failing to assess quality of life / sleep before escalating therapy.

References5Show

[1]Langan SM, Irvine AD, Weidinger S. Atopic dermatitis. Lancet, 2020.PMID 32738956
[2]Sidbury R, Davis DMR, Cohen DE, et al. Guidelines of care for the management of atopic dermatitis in adults with topical therapies. Journal of the American Academy of Dermatology, 2023.PMID 36641009
[3]Simpson EL, Bieber T, Guttman-Yassky E, et al. Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis. New England Journal of Medicine, 2016.PMID 27690741
[12]Davis DMR, Drucker AM, Alikhan A, et al. Guidelines of care for the management of atopic dermatitis in adults with phototherapy and systemic therapies. J Am Acad Dermatol, 2024.PMID 37943240
[4]Drislane C, Irvine AD. The role of filaggrin in atopic dermatitis and allergic disease. Annals of Allergy, Asthma & Immunology, 2020.PMID 31622670

Brief (to candidate)

Candidate instructions

Take a focused history (onset, distribution, triggers, atopy, sleep, school impact, prior treatments). ^[1]

Examine skin morphology and distribution; state when you would examine eyes/lymph nodes.

Grade severity and name validated scores (EASI / SCORAD / IGA / DLQI).

Identify red flags (eczema herpeticum, erythroderma, secondary bacterial infection).

Outline stepwise management (emollients → topicals → phototherapy/systemic/biologic) with safety checks.

Give safety-net and follow-up advice.

Examiner checklist (mark each domain / 10)

Domain	Key actions expected
Recognition	Poorly demarcated erythematous, lichenified flexural patches; itch–scratch cycle; age-dependent distribution (infant face/extensors → childhood flexures)^[1]
History & atopy	Personal/family atopy (asthma, rhinitis, food allergy); filaggrin/barrier concept; triggers (irritants, infection, climate)^[4]
Severity	Names EASI / SCORAD / IGA and impact (sleep, school); distinguishes mild vs moderate-to-severe needing systemic step-up
Red flags	Eczema herpeticum (monomorphic punched-out erosions + fever) — urgent antivirals/admission; also erythroderma, severe secondary infection
Stepwise Rx	Daily emollients + soap substitute; topical corticosteroid (appropriate potency by site) ± calcineurin inhibitor for face/folds; wet wraps for flares; antibiotic only if infected^[2]
Systemic / biologic	For refractory moderate–severe disease: phototherapy or systemic (e.g. cyclosporine short course) / dupilumab (IL-4Rα); pre-treatment infection screen and vaccination planning as appropriate^[3]
Communication	Explains chronic relapsing course; steroid phobia counselling; return if fever, punched-out erosions, or rapid worsening

Model key actions

Recognise chronic flexural eczema with barrier/type-2 inflammation framing.^[1]

Exclude eczema herpeticum in this febrile, monomorphic-erosion presentation — treat as emergency (systemic aciclovir/admission pathway). ^[1]

Ladder: emollient foundation → topical anti-inflammatory → phototherapy/systemic → dupilumab for refractory disease.^[2]^[3]

Address sleep, school, and parental steroid concerns; plan review after flare control.

Common errors

Missing eczema herpeticum and treating as bacterial impetigo alone. ^[1]

Systemic corticosteroids as long-term control (rebound/side effects).^[12]

Antibiotic or topical steroid without emollient foundation.

Using potent steroids long-term on face/folds without TCI option.

Failing to assess quality of life / sleep before escalating therapy.

References5Show

[1]Langan SM, Irvine AD, Weidinger S. Atopic dermatitis. Lancet, 2020.PMID 32738956
[2]Sidbury R, Davis DMR, Cohen DE, et al. Guidelines of care for the management of atopic dermatitis in adults with topical therapies. Journal of the American Academy of Dermatology, 2023.PMID 36641009
[3]Simpson EL, Bieber T, Guttman-Yassky E, et al. Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis. New England Journal of Medicine, 2016.PMID 27690741
[12]Davis DMR, Drucker AM, Alikhan A, et al. Guidelines of care for the management of atopic dermatitis in adults with phototherapy and systemic therapies. J Am Acad Dermatol, 2024.PMID 37943240
[4]Drislane C, Irvine AD. The role of filaggrin in atopic dermatitis and allergic disease. Annals of Allergy, Asthma & Immunology, 2020.PMID 31622670