Cases/Dermatology

Itchy, Darkened Skin Patches — Free SCA Practice Case

Man with itchy, darkened skin patches

Station Timer

12:00

Golden Minute

Initial Introduction

•Introduce yourself

•Ask an open question — "How can I help you today?"

•Listen — don't interrupt

•Catch early cues

Data Gathering

History, ICE & Diagnosis

Clinical Management

Diagnosis, Plan & Decisions

Safety Net

Follow-up & Close

12:00

Golden Minute

Materials for Candidate

Please review before starting the consultation

Patient Profile

Full Name

Marcus Okonjo

Age

32 years

Consultation Type

Telephone

Age

32 (DOB: 12/08/1993)

Situation

Telephone Consultation.

Reason for Encounter

"My skin is driving me mad. It's so itchy, and now it's turning black and rough. I look terrible."

Medical Records

●PMH: Asthma (childhood, now resolved), Allergic Rhinitis (Hay fever).
●Medications: Cetirizine 10mg PRN.
●Allergies: NKDA.

Examination (Visuals provided during consult)

●Photograph: The patient uploads some photos of the antecubital fossae (inside elbows) and neck. The skin is extremely dry and thickened (lichenified) with exaggerated skin markings. The affected areas are significantly darker (hyperpigmented) than the surrounding skin. There is no bright redness, but the skin looks greyish/violet in tone.

Eczema patches in antecubital fossae

Eczema patches on neck

Patient Script

For the friend playing the patient role

Character Overview: You are Marcus. You are frustrated and self-conscious. You work in sales, and you feel like clients are staring at your neck and arms. You are worried that the dark, rough patches are permanent or "fungal". You have been scratching intensely, especially at night.

Opening Sentence: "Hi Doctor. I need something strong for my skin. It's been itchy for months, but now look at it—it's gone all thick and dark. It looks like elephant skin. I'm embarrassed to wear short sleeves."

History if Asked (Data Gathering Phase)

●The Itch: "It's 10/10. I scratch until I bleed, especially when I'm stressed or hot. The scratching feels good for a second, but then it burns."
●The Appearance (Skin of Colour context): "It never really went 'red' like they say on Google. It just got dry, bumpy, and now this dark brown/black colour. Is that dirt? Is it scarring?"
●Current Management: "I've been using Cocoa Butter and some E45, but they just disappear. I tried a chemist's cream (Hydrocortisone) for a few days, but it did absolutely nothing."
●Triggers: "Sweat makes it worse. Wool jumpers make it worse."
●Impact: "I'm waking up 3 or 4 times a night scratching. My wife is annoyed because I'm restless."

ICE — Ideas, Concerns, Expectations

The patient does not volunteer this information unprompted. These responses surface only when the candidate directly explores the patient's perspective.

●Ideas: Marcus thinks the dark patches might be a fungal infection or some kind of permanent skin damage. He has never considered eczema — he associates it with children and with redness, neither of which fits his experience. "I thought it might be a fungus or something — the way it's gone dark and rough like that. It doesn't look like anything I've seen on the internet for eczema."
●Concerns: His biggest worry is that the dark discolouration is permanent. He is also deeply self-conscious about how it looks at work — he feels it affects how clients perceive him. "Honestly, the itching I can deal with, but the colour — I hate it. I feel like people think I'm dirty or not looking after myself. I work face-to-face with clients every day and I can't hide it."
●Expectations: He wants something strong that will actually work — the over-the-counter approaches have failed and he feels dismissed. He also wants a clear answer about whether the dark marks will fade. "I just want something that actually works this time. And I need to know — will the dark bits go back to normal? Because that's the bit that's really getting to me."

If Asked — Medical History and Medications

The patient confirms these details only when directly asked by the candidate.

●Childhood asthma: "I had asthma as a kid — used to have inhalers and everything. But I grew out of it, probably by about 14 or 15. I haven't needed anything for it since."
●Hay fever / allergic rhinitis: "Yeah, I get hay fever every summer — sneezing, itchy eyes, the usual. It's been like that since I was a teenager. I just take an antihistamine when it flares up."
●Cetirizine 10mg: "I take cetirizine when my hay fever's bad, but I've been taking it more regularly lately hoping it would help the itching. It takes the edge off the sneezing but honestly hasn't done much for the skin."
●Family history of atopy (if asked): "My mum has asthma and my younger sister had eczema when she was little — she grew out of it though."
●Allergies: "No, no allergies to any medicines that I know of."

Social History and Lifestyle Impact

Marcus works as a sales consultant for a technology firm. He is client-facing most days, often in meetings where he is presenting or shaking hands. He lives with his wife in a flat.

●Work impact: "I'm in sales — I'm meeting clients all day. I used to wear shirts with the sleeves rolled up, but now I can't. Even with long sleeves, people can see my neck. I had a big presentation last week and I couldn't stop thinking about whether they were staring at it. I'm losing confidence, honestly."
●Sleep impact: "I'm shattered. I'm waking up three or four times a night tearing at my skin. My wife has started sleeping in the spare room because I'm keeping her up. It's putting a strain on things."
●Daily life: "Even simple stuff — going to the gym, I feel like everyone's looking. I've stopped going. I used to swim but there's no way I'm getting in a pool looking like this."

If Asked — Associated Symptoms

The patient answers these only when directly asked by the candidate.

●If asked about symptoms elsewhere on the body: "It's mainly the insides of my elbows and my neck. My hands get a bit dry and cracked sometimes too, but nothing as bad as these patches."
●If asked about weeping or oozing from the skin: "No, it's not weepy or wet — it's bone dry. Just thick and rough."
●If asked about any blistering: "No blisters, no."
●If asked about fever or feeling unwell: "No, I feel fine in myself — it's just the skin."
●If asked about joint pain or swelling: "No, nothing like that."
●If asked about eye symptoms (itchy, watery, or dry eyes): "My eyes get a bit itchy sometimes, especially in hay fever season, but nothing major."
●If asked about recent skin infections or crusting: "No, nothing like that — no yellow crusting or anything oozy."
●If asked about dietary changes or new products: "No, nothing new. Same shower gel, same washing powder. I haven't changed anything."
●If asked about stress: "Yeah, work has been really stressful the last few months — big targets, long hours. That's probably when it got worse, now I think about it."
●If asked about contact with irritants at work: "No, it's all office-based. Just a laptop and a phone, really."
●If asked about recent foreign travel: "No, haven't been abroad in about a year."
●If asked about weight loss or appetite changes: "No, eating fine, weight's the same."

Responses to Management (The Negotiation Phase)

●If the Doctor diagnoses Eczema: "Eczema? I thought that was a kid's thing. And isn't eczema supposed to be red? This looks black."
●If the Doctor prescribes a 'Grease' (Ointment): "I can't go to work looking greasy. Can't I have a cream that sinks in?" (Doctor needs to explain why ointments are better for dry/thick skin).
●If the Doctor discusses the Pigmentation: "Will the dark marks go away? That's the bit I hate most."
●If the Doctor suggests stopping scratching: "Easier said than done, Doc. It's uncontrollable."

Mark Scheme

Domain 1: Data Gathering and Diagnosis

0 / 16 indicators checked+0−0

Positive (0/8)

Negative (0/8)

Domain 2: Clinical Management and Medical Complexity

0 / 28 indicators checked+0−0

Positive (0/14)

Negative (0/14)

Domain 3: Relating to Others

0 / 20 indicators checked+0−0

Positive (0/10)

Negative (0/10)

Clinical Learning Points

Eczema in Skin of Colour

●Erythema is often absent or non-prominent in pigmented skin. Inflammation presents as violet, grey, or dark brown discolouration rather than the classical bright red seen in lighter skin tones — and this discrepancy is a major reason patients (and clinicians) fail to recognise eczema in this group.
●Post-inflammatory hyperpigmentation (PIH) is caused by melanin deposition into the dermis during chronic inflammation. It is one of the most distressing features for patients with darker skin tones and should be explicitly acknowledged and explained.
●Key message for patients: Treating the underlying inflammation is the only evidence-based route to fading the dark marks. Skin-lightening or bleaching products are not appropriate first-line management and should not be prescribed.
●Follicular eczema: A common morphological variant in pigmented skin where inflammation centres around hair follicles, giving a rough, goosebump-like texture. This may be the predominant pattern rather than confluent plaques.
●PIH typically fades over weeks to months once inflammation is controlled — provide realistic, honest reassurance rather than promising rapid resolution.

Diagnosing Atopic Eczema — The Atopic Triad

●Atopic eczema, asthma, and allergic rhinitis form the atopic triad. The presence of two or three elements significantly supports an atopic diagnosis.
●A positive personal or family history of atopy substantially raises the pre-test probability of atopic eczema — always ask.
●Classic adult distribution: flexural surfaces (antecubital and popliteal fossae), neck, wrists, and ankles. This contrasts with the childhood pattern of facial and extensor involvement.
●Lichenification — skin thickening with exaggerated surface markings from chronic rubbing — is a hallmark of longstanding, inadequately treated disease, not a separate diagnosis. It forms through the itch-scratch cycle and indicates significant chronicity.
●Adult-onset or adult-persistent eczema is common and frequently misattributed. Correcting the misconception that eczema is a childhood condition is an important part of patient education.

Investigations

●Atopic eczema is a clinical diagnosis — no routine investigations are required in a straightforward presentation with clear atopic history and typical distribution.
●Consider swabs for bacterial culture only if secondary infection is suspected (weeping, crusting, pustules, fever, or failure to respond to topical treatment) — not as a routine step.
●Patch testing is indicated when allergic contact dermatitis (ACD) is suspected as a trigger or co-diagnosis — particularly in atypical distributions or where identified triggers do not fit the atopic pattern. This requires dermatology referral.
●Serum IgE and RAST/specific IgE testing are not routinely recommended in primary care for straightforward atopic eczema diagnosis (NICE CKS).

Topical Corticosteroid Prescribing — Potency, Formulation, and Technique

●Match potency to severity and site. Lichenified skin requires a potent topical corticosteroid (e.g., betamethasone valerate 0.1% or mometasone furoate 0.1%) as first-line — mild steroids (hydrocortisone 1%) and moderate steroids (clobetasone butyrate 0.05%) are inadequate for established lichenification.
●A very potent steroid (e.g., clobetasol propionate 0.05%) may be appropriate for the most resistant lichenified plaques under specialist guidance or in primary care with short-course, clearly defined safety advice.
●Formulation: Ointments are preferred over creams for dry, lichenified skin — they provide superior occlusion, deeper penetration through thickened skin, contain fewer preservatives, and cause less stinging on broken skin. Creams are acceptable for acutely weeping lesions or where ointment adherence is a genuine barrier to treatment.
●Prescribing detail matters: Provide clear instructions — once or twice daily application, course duration (typically 7–14 days for a flare), fingertip unit (FTU) guidance for quantity, and specific body sites. Vague prescribing leads to under-treatment or inappropriate prolonged use.
●Step-down approach: Potent steroid for the active flare, then step down to a lower-potency agent or stop once controlled. Do not continue potent steroids indefinitely on the same site.
●Occlusion: Applying ointment under a cotton bandage or cotton gloves at night (wet or dry wrapping) can significantly enhance absorption through lichenified plaques and reduces nocturnal scratching — a particularly useful strategy when sleep disruption is prominent.
●Body site restrictions: Avoid potent or very potent steroids on the face, flexures (long-term), and genitalia without specialist input due to risk of skin atrophy.

Emollient Strategy

●Emollients are the cornerstone of long-term eczema management and should be used continuously — not just during flares. Liberal and frequent application (at least twice daily) is recommended.
●For dry, lichenified skin, heavy ointment-based emollients (e.g., Diprobase ointment, Epaderm ointment, 50:50 white soft paraffin/liquid paraffin) provide superior barrier support compared to lighter creams or lotions.
●Aqueous cream must not be used as a leave-on emollient. It contains sodium lauryl sulphate (SLS), a detergent that damages the skin barrier and worsens eczema. It may be used as a wash-off soap substitute only, though dedicated SLS-free emollients (e.g., Zerobase, Cetraben, Epaderm) are preferable even for this purpose.
●Prescribe a soap substitute for all washing — standard soaps and many shower gels strip the skin barrier and should be avoided.
●Apply emollient first; allow it to absorb for 30 minutes before applying topical corticosteroid to the same area (reduces dilution of the steroid).

Breaking the Itch-Scratch Cycle

●Scratching causes lichenification, which causes further itch, which drives further scratching — a self-perpetuating cycle. Breaking it requires a multimodal approach.
●Practical strategies: Keep fingernails short; wear cotton gloves at night; use cool compresses or a cool fan to the affected area; distraction techniques during the day.
●Sedating antihistamines (e.g., chlorphenamine or hydroxyzine) at night do not directly treat the itch of eczema (which is not histamine-mediated) but the sedating effect helps patients sleep through the itch, reducing nocturnal scratching and improving sleep quality. Non-sedating antihistamines (e.g., cetirizine) have limited evidence for eczema itch and should not be the primary antihistamine recommendation for this purpose.
●Acknowledge explicitly that the itch is severe and largely involuntary — advising patients to 'just stop scratching' without offering practical strategies is unhelpful and damages the therapeutic relationship.

Trigger Avoidance

●Identified triggers in this case: sweat (heat), wool clothing, and psychological stress.
●Advise cotton clothing and breathable fabrics; avoid wool and synthetic fibres directly against the skin.
●Temperature regulation: keep cool, particularly at night — overheating is a common and underappreciated trigger. Lightweight bedding and cool sleeping environments reduce nocturnal itch.
●Stress: acknowledge the bidirectional relationship between psychological stress and eczema flares. Stress management strategies (exercise, sleep hygiene, mindfulness) are clinically relevant, not just supportive.
●Avoid over-investigation for food triggers in adult atopic eczema without a clear clinical history suggesting food-driven exacerbation — this is rarely the cause in adults and elimination diets can cause nutritional harm.

Referral Criteria

●
Refer to dermatology if:
- ●Eczema fails to respond to a 4–8 week course of potent topical corticosteroid with optimised emollient use
- ●Diagnostic uncertainty (e.g., suspicion of ACD, psoriasis, or other differential)
- ●Severity warrants consideration of second-line systemic treatment: phototherapy (narrowband UVB), dupilumab (licensed for moderate-to-severe atopic eczema in adults), ciclosporin, methotrexate, or azathioprine
- ●Frequent infective flares requiring systemic antibiotics
- ●Significant psychological morbidity that warrants specialist input
●Dupilumab (an IL-4/IL-13 receptor antagonist) is available on the NHS for adults with moderate-to-severe atopic eczema that has failed conventional systemic immunosuppression.

Safety Netting and Follow-up

●Review in 2–4 weeks to assess treatment response, check emollient adherence, step down or adjust steroid potency, and review the need for ongoing management.
●Discuss the chronic relapsing nature of atopic eczema — long-term emollient use is recommended even during clear periods to maintain the skin barrier and reduce relapse frequency.
●Signs of secondary bacterial infection to act on promptly: increased pain or tenderness, weeping, yellow crusting, pustules, fever, or rapid deterioration despite treatment. These warrant prompt reassessment and may require topical (fusidic acid) or systemic antibiotics (flucloxacillin first-line).
●Advise the patient to return if: the skin does not improve after 2 weeks of treatment; new symptoms develop; or there is any concern about infection.
●National Eczema Society (eczema.org) provides high-quality patient resources — signposting is valuable for patients managing a chronic condition.

Common Candidate Mistakes in This Case

●Prescribing too weak a steroid: Reaching for hydrocortisone 1% or clobetasone 0.05% in the face of established lichenification is the single most common prescribing error in this presentation. The skin is too thick for these agents to penetrate effectively.
●Missing the atopic triad: Failing to connect childhood asthma and hay fever to the current presentation misses the diagnostic framework and the opportunity to explain eczema as part of a broader atopic tendency.
●Not addressing the pigmentation: Marcus's primary concern is the dark discolouration, not the itch. Candidates who focus entirely on the itch and ignore the hyperpigmentation fail to respond to the patient's actual priority — a pattern that will be penalised in Domain 3 as well as Domain 2.
●Dismissing or ignoring skin of colour considerations: Asking repeatedly whether the skin is red, or failing to acknowledge that eczema looks different in darker skin tones, demonstrates a significant gap in clinical awareness and will be reflected in negative indicators across multiple domains.
●Prescribing cream without discussion: Defaulting to cream because the patient expresses reluctance about ointment, without negotiating a practical compromise, represents a missed opportunity for shared decision-making and results in a suboptimal treatment plan.

Free MRCGP SCA practice case for GP registrars covering Itchy, Darkened Skin Patches — Dermatology. Includes candidate brief, patient script, marking scheme mapped to the RCGP SCA marking domains, and learning points. Built directly from the RCGP curriculum topic stations listed under "How this might be tested in the MRCGP SCA," part of a free library of 79 SCA practice cases for simulated consultation assessment preparation.

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