Skin Lesions (pigmented)
Pigmented skin lesions are areas of skin with altered coloration due to changes in melanin production, melanocyte proliferation, or vascular abnormalities, ranging from benign nevi and seborrheic keratoses to malignant melanoma.
Murtagh Diagnostic Strategy
| Category | Diagnosis | Key Discriminator | Cantonese Question / Finding |
|---|---|---|---|
| Probability Diagnosis | Seborrheic keratosis | "Stuck-on" waxy appearance, well-circumscribed, can be picked off [3][4] | 「粒嘢表面係咪好似油油噉，好似貼住喺皮膚上面？」(Is it waxy/greasy and stuck-on?) |
| Melanocytic naevus (mole) | Symmetric, uniform colour, smooth border, ≤6mm, stable [5] | 「粒嘢形狀同顏色一直都冇變過？」 | |
| Solar lentigo ("age spot") | Uniform tan/brown, sun-exposed area, flat, sharply demarcated [5] | 「係咪平嘅、啡色、喺成日曬到嘅位？」 | |
| Serious Not To Miss | Malignant melanoma | ABCDE +ve, rapid change, bleeding, satellite lesions; acral lentiginous is most common subtype in HK [1][2] | 「粒嘢有冇一邊大一邊細？顏色有冇深淺唔均勻？最近有冇越嚟越大？」 |
| Basal cell carcinoma (BCC) | Pearly/pigmented nodule, telangiectasia, rolled edge, central ulcer; 80% pigmented in HK [2][6] | 「邊位有冇好似血管嘅紅絲？中間有冇凹落去或者爛咗？」 | |
| Squamous cell carcinoma (SCC) | Everted edges, crusted, contact bleeding, may have keratin horn [2] | 「粒嘢表面有冇硬殼或者容易流血？」 | |
| Pitfalls | Dysplastic naevus | >5mm, variegated, ill-defined border, fried-egg appearance [5] | 「粒痣有冇比其他痣大好多、顏色唔均勻？」(Ugly duckling sign) |
| Dermatofibroma | Firm, hyperpigmented nodule, +ve buttonhole/dimple sign [7] | PE: pinch → dimple sign | |
| Pigmented actinic keratosis | Scaly, on sun-damaged skin; pre-malignant for SCC [5] | 「粒嘢表面係咪粗粗哋、有皮屑？」 | |
| Masquerades | Drug-induced pigmentation | Temporal correlation with medication (amiodarone, minocycline) | 「你最近有冇開始食新藥？」 |
| Post-inflammatory hyperpigmentation | History of prior dermatitis/injury at same site | 「嗰個位以前有冇發過炎或者損傷過？」 | |
| Trying to Tell Me Something? | Cancer anxiety / health anxiety | Triggered by friend/relative diagnosed with skin cancer | 「係咪有人提過你或者身邊有人唔好，所以你先嚟睇？」 |
| Cosmetic/body image concern | Visible lesion on face affecting self-esteem | 「外觀上對你有冇困擾？」 |
| Time | Task | Cantonese Key Phrases | Why It Scores Marks |
|---|---|---|---|
| 0:00–0:30 | Friendly opening, rapport | 「你好，我係XX醫生，今日由我同你傾吓，唔洗緊張㗎。」「我可以點樣稱呼你？」 | Interpersonal marks: greeting, permission, setting agenda |
| 0:30–1:30 | Chief complaint + HPI – onset, site, change over time, ABCDE features | 「你今日嚟主要想睇啲咩呢？」「呢粒嘢幾時開始有㗎？」「最近有冇變大咗、變色、出血或者痕？」「形狀有冇唔規則？」 | Captures CC, HPI systematically; covers red flags for melanoma |
| 1:30–2:30 | ICE + hidden agenda – explore why today, what worries them | 「你自己覺得呢粒嘢可能係咩嚟㗎？」(Idea) 「你最擔心嘅係咩？」(Concern – often cancer fear) 「你希望今日我哋可以幫到你啲咩？」(Expectation) | ICE is marks-bearing; hidden agenda often = cosmetic concern OR cancer anxiety |
| 2:30–3:30 | Targeted Hx – sun exposure, FHx melanoma/skin CA, occupation, mole changes, immunosuppression, meds | 「你份工係咪成日會曬太陽？」「屋企人有冇試過生過皮膚癌？」「你有冇食緊啲咩藥？」 | Risk factors & DDx discriminators |
| 3:30–4:30 | Systems review + PMH + social Hx – other skin lesions, constitutional Sx, DM, psych impact | 「你身體其他地方有冇類似嘅嘢？」「最近有冇瘦咗、冇胃口？」「呢粒嘢有冇影響你嘅心情或者日常生活？」 | Biopsychosocial; pick up masquerade or systemic disease |
| 4:30–5:15 | Signpost → physical exam mention + summarise | 「我想總結吓你講嘅嘢，睇吓有冇漏咗…」「如果可以嘅話，我想檢查吓呢粒嘢同附近嘅淋巴。」 | Signposting & summarising = interpersonal marks |
| 5:15–6:00 | Close: plan, safety-net, check understanding | 「根據你講嘅情況，我建議幫你轉介皮膚科做進一步檢查。」「如果粒嘢突然變大、流血或者痛，要即刻返嚟睇。」「你有冇其他問題想問？」 | Safe close with safety-net and red-flag counselling |
Uncovering the hidden agenda: The patient with a pigmented skin lesion often presents because (a) they noticed a change and fear cancer, (b) cosmetic concern, or (c) it was pointed out by a relative. Ask: 「點解你揀咗今日嚟睇？係咪有啲嘢令你特別擔心？」
| Domain | English Question | Cantonese Question | Why It Matters | If Positive Think Of |
|---|---|---|---|---|
| Onset/Duration | When did you first notice this lesion? | 「呢粒嘢你幾時第一次留意到㗎？」 | New vs long-standing; rapid growth = red flag | Melanoma, BCC, keratoacanthoma |
| Change (ABCDE) | Has it changed in size, shape, colour, or border? | 「佢有冇變大、變形、變色、邊界變得唔規則？」 | ABCDE rule is the core screening tool for melanoma [1][2] | Melanoma |
| Symptoms | Does it itch, bleed, hurt, or ooze? | 「有冇痕、流血、痛或者出水？」 | Bleeding/ulceration = malignancy red flag | Melanoma, SCC, BCC |
| Number | Is this the only one or are there others? | 「淨係得呢一粒定仲有其他？」 | Multiple = seborrheic keratosis; sudden multiple = Leser-Trélat sign [3] | Seborrheic keratosis, internal malignancy |
| Sun exposure | Do you get a lot of sun? Any sunburn history? | 「你平時會唔會成日曬太陽？以前有冇試過曬傷？」 | Major RF for all skin cancers | Melanoma, BCC, SCC, solar lentigo |
| Occupation | What is your job? Outdoor work? | 「你做咩工㗎？係咪喺室外做嘢？」 | Chronic UV exposure | SCC, actinic keratosis |
| FHx | Any family history of skin cancer or melanoma? | 「屋企人有冇人試過有皮膚癌或者黑色素瘤？」 | FHx melanoma ↑risk significantly | Melanoma, dysplastic naevus syndrome |
| PMH | Any history of immunosuppression or organ transplant? | 「你有冇長期食抑制免疫力嘅藥？做過器官移植？」 | Immunosuppression ↑skin CA risk | SCC, BCC, Kaposi sarcoma |
| Drug Hx | Are you on any medications? | 「你有冇食緊啲咩藥？」 | Drug-induced pigmentation (e.g. amiodarone, minocycline, hydroxychloroquine) | Drug-related hyperpigmentation |
| Cosmetic concern | Does the appearance bother you? | 「外觀上你會唔會介意？」 | Psychological/social impact; may be the real RFC | Cosmetic concern as hidden agenda |
| Psych impact | Has this affected your mood or daily life? | 「呢件事有冇影響到你心情或者日常生活？」 | Biopsychosocial | Anxiety, body image distress |
| Constitutional Sx | Any weight loss, fatigue, or loss of appetite? | 「最近有冇瘦咗、攰咗、冇胃口？」 | Screen for metastatic disease or systemic malignancy | Metastatic melanoma, Leser-Trélat (internal CA) |
Case Report Form Answer Builder
- "Pigmented skin lesion on [site] for [duration]"
- Include: onset, site, size, colour, change over time (ABCDE features), symptoms (itch/bleed/pain), sun exposure history, FHx skin cancer, previous Tx
- Examples: "Concerned about recent change in a mole" / "Worried the lesion might be cancer" / "Cosmetic concern about a facial pigmented lesion"
- Pick the ONE that best matches what triggered the visit today
| Likely Wording | |
|---|---|
| Idea | "I think it might be a mole / skin cancer / age spot" |
| Concern | "I am worried it could be cancer because it has been growing / my relative had melanoma" |
| Expectation | "I would like you to check if it is dangerous / I want it removed / I want reassurance" |
- Seborrheic keratosis (if elderly, "stuck-on", stable, waxy) – most common pigmented lesion in primary care
- Melanocytic naevus (if younger, symmetric, stable)
- Choose based on stem: age, lesion description, stability vs change
- Minimum evidence: well-circumscribed, "stuck-on" waxy plaque, stable, no ABCDE features
| DDx | One Discriminator |
|---|---|
| Malignant melanoma | ABCDE +ve, rapid change, variegated colour |
| BCC | Pearly/pigmented nodule, telangiectasia, rolled edge (80% pigmented in HK) |
| Solar lentigo | Flat, uniform brown, sun-exposed, stable |
| Domain | Problem |
|---|---|
| Biological | Risk of malignant transformation / undiagnosed skin cancer |
| Psychological | Anxiety about cancer / body image concern |
| Social | Cosmetic impact on social interactions / occupational UV exposure |
| Diagnosis/DDx | Best Supporting Physical Sign | How to Elicit | Why It Supports |
|---|---|---|---|
| Seborrheic keratosis | "Stuck-on" appearance with rough/waxy surface | Visual inspection; lesion appears to sit on top of skin surface | Pathognomonic for SK; can be picked off with blunt forceps [3][4] |
| Melanoma | Asymmetric shape + variegated colour (ABCDE) | Visual inspection with good lighting ± dermoscopy | ABCDE criteria differentiate melanoma from benign naevi [1][2] |
| BCC | Pearly/pigmented nodule with telangiectasia and rolled edge | Visual inspection; look for surface blood vessels and central ulcer | Classic BCC morphology; pigmented in 80% HK patients [2][6] |
| Dermatofibroma | Dimple/buttonhole sign | Pinch the lesion laterally → central dimple appears | Pathognomonic for dermatofibroma [7] |
| Melanocytic naevus | Symmetric, uniform colour, ≤6mm, smooth border, stable | Visual inspection | Negative ABCDE features = benign naevus [5] |
Must-Not-Miss Red Flags – Refer Urgently
- ABCDE positive: Asymmetry, Border irregular, Colour variegated, Diameter > 6mm, Evolving [1][2]
- Bleeding, ulceration, or satellite lesions
- New pigmented lesion in an immunosuppressed patient
- Subungual pigmented streak with Hutchinson's sign (pigment extending onto nail fold) → acral lentiginous melanoma (most common melanoma subtype in HK – 52%) [2]
- Sudden eruption of multiple seborrheic keratoses → Leser-Trélat sign → screen for internal malignancy [3][4]
Top Traps That Lose Marks:
- Forgetting to ask about CHANGE – a stable mole vs an evolving lesion is the key discriminator
- Not asking ICE – the hidden concern is almost always cancer fear; if you miss this you lose interpersonal AND case report marks
- Writing "mole" as diagnosis when ABCDE features are present – must consider melanoma
- Ignoring BCC because it's "not pigmented" – in HK, 80% of BCCs are pigmented [2][6]; don't default to Caucasian presentation
- Forgetting acral sites – always ask about palms, soles, nail beds for acral lentiginous melanoma in Asian patients [2]
- Not examining regional lymph nodes – any pigmented lesion suspicious for malignancy needs LN palpation [1]
Safety-Net Closing Line: 「如果粒嘢突然變大、變色、流血或者痛，要即刻返嚟或者去急症室。」("If the lesion suddenly grows, changes colour, bleeds, or hurts, come back immediately or go to A&E.")
High Yield Summary
What to ASK: ABCDE features, duration/change, bleeding, sun exposure, FHx, occupation, ICE (cancer fear), psych impact
What to WRITE: CC with site + duration; RFC = concern about change/cancer; ICE verbatim; Dx = seborrheic keratosis (if stable/stuck-on) or melanocytic naevus; DDx = melanoma, BCC, solar lentigo; Biopsychosocial = malignancy risk + cancer anxiety + cosmetic/social impact; Sign = "stuck-on" appearance (SK) or ABCDE features (melanoma)
What NOT to MISS: ABCDE +ve → melanoma; pigmented nodule with telangiectasia → BCC (80% pigmented in HK); acral lentiginous melanoma (most common in HK); Leser-Trélat sign; Hutchinson's sign; always palpate regional LN
Active Recall - Family Medicine Clinical Test
[1] GC 201. Skin ulcers skin and subcutaneous lesions; skin cancer.pdf (Melanoma slide, skin lesion overview) [2] Maksim Surgery Notes.pdf (Skin cancers section – BCC, SCC, melanoma subtypes, ABCDE rule) [3] MBBS Final MB (Surgery) (Felix PY Lai).pdf (Seborrheic keratosis, Leser-Trélat sign) [4] Ryan Ho Rheumatology.pdf (Seborrheic keratosis – stuck-on appearance; neoplastic lesion table) [5] Ryan Ho Rheumatology.pdf (Freckles, lentigo, naevus comparison table; dysplastic naevus; lentigo maligna; melanoma examination) [6] Ryan Ho Rheumatology.pdf (BCC – 80% pigmented in HK, examination and DDx) [7] Ryan Ho Rheumatology.pdf (Dermatofibroma – buttonhole/dimple sign)
Skin Itch (pruritus)
Pruritus is an unpleasant cutaneous sensation that provokes the desire to scratch, arising from dermatological, systemic, neurogenic, or psychogenic causes.
Skin Rash
A skin rash is a visible change in the color, texture, or appearance of the skin, often manifesting as redness, bumps, or lesions, resulting from inflammatory, infectious, allergic, or systemic causes.