Family medicine
Vulvar Irritation Or Dermatitis
Vulvar irritation or dermatitis is an inflammatory condition of the vulvar skin caused by contact irritants, allergens, or underlying dermatoses, presenting with erythema, pruritus, and discomfort.
Murtagh Diagnostic Strategy
| Category | Diagnosis | Key Discriminator | Cantonese Question / Finding |
|---|---|---|---|
| Probability Diagnosis | Vulvovaginal candidiasis | White curd-like discharge, intense itch, erythema; often post-antibiotics or in DM/pregnancy | 「有冇白色好似豆腐渣噉嘅分泌物？最近有冇食過抗生素？」 |
| Irritant contact dermatitis (ICD) | 80% of contact dermatitis cases [5]; burning > itch; exposure to soap/pads/urine; reaction limited to contact site | 「你平時用乜嘢洗下面？有冇覺得灼痛多過痕？」 | |
| Atopic/endogenous eczema (vulvar) | Personal/FHx atopy; flexural distribution; chronic relapsing itch with lichenification | 「你自己有冇濕疹、鼻敏感、哮喘？」 | |
| Serious Not To Miss | Vulvar intraepithelial neoplasia (VIN) / SCC | Non-healing ulcer/plaque; bleeding; older age; immunosuppression; HPV history | 「有冇嗰度爛咗好耐都唔好？有冇出血？」 |
| Lichen sclerosus | White atrophic patches in "figure-of-8" pattern; postmenopausal; risk of SCC (4–5%) | 「嗰度有冇變白色或者變薄？」Exam: porcelain-white atrophic plaques | |
| Genital herpes (HSV) | Painful grouped vesicles/ulcers; systemic symptoms in primary; sexual contact Hx | 「有冇生過水泡？好痛嗰種？」 | |
| Pitfalls | Allergic contact dermatitis (ACD) | Requires prior sensitisation; crescendo reaction on patch test (vs decrescendo in ICD) [6]; Hx of new product | 「最近有冇轉用新嘅藥膏、清潔劑、或者衛生巾？」 |
| Tinea cruris | Annular advancing border with central clearing; KOH +ve; may be masked by prior steroid (tinea incognito) | 「嗰度有冇一圈圈噉嘅紅？之前有冇搽過類固醇？」 | |
| Vulvar psoriasis | Well-demarcated erythematous plaques, lacks typical silvery scale in flexural areas; Hx of psoriasis elsewhere | 「你身體其他地方有冇類似嘅紅色一嚿嚿？頭皮？指甲？」 | |
| Masquerades | Diabetes mellitus | Recurrent candidiasis; polyuria/polydipsia | 「你有冇糖尿病？有冇口渴、尿多？」 |
| Drug reaction (fixed drug eruption) | Recurring lesion at same site after drug intake | 「每次食某隻藥之後有冇同一個位出事？」 | |
| Depression / stress | Lichen simplex chronicus from habitual scratching driven by anxiety | 「你最近壓力大唔大？心情點？」 | |
| Trying to Tell Me Something? | Fear of STI / relationship concern | New partner; partner infidelity suspected; embarrassment | 「你有冇擔心呢個問題同性病有關？伴侶方面有冇令你擔心嘅嘢？」 |
| Body image / sexual dysfunction | Avoiding intimacy; self-consciousness | 「呢個問題有冇影響到你同伴侶嘅親密關係？」 |
Minute-by-Minute 6-Minute Consultation
| Time | Task | Cantonese Key Phrases | Why It Scores Marks |
|---|---|---|---|
| 0:00–0:30 | Friendly opening, rapport, set agenda | 「你好，我係X醫生。今日想同你傾下你嘅情況，我會問你幾條問題，之後做個總結，係咪可以呢？」(Hello, I'm Dr X. I'd like to chat about your situation today, ask some questions, then summarise — is that OK?) | Permission-seeking + signposting → interpersonal marks |
| 0:30–2:00 | Open history: chief complaint + HPI | 「可唔可以話俾我聽，下面痕嗰個情況幾時開始㗎？」「嗰度有咩感覺？痕？痛？紅？」「有冇嘢令到佢嚴重啲或者好啲？」 | Core symptom analysis: onset, site, character, aggravating/relieving factors |
| 2:00–3:00 | Red flags + targeted Hx + sexual/menstrual Hx | 「有冇流嘢落嚟？有冇異味？有冇生粒粒或者損爛？」「最近有冇用過新嘅清潔劑、衛生巾、或者新嘅底褲？」「我想問一啲比較私人嘅嘢，可以嗎？你最近有冇性行為？」 | Detects contact irritant, STI, vulvar malignancy; permission before sensitive questions |
| 3:00–3:45 | PMHx, DHx, Allergy, FHx, Social Hx | 「你有冇乜嘢長期病？」「有冇食緊乜嘢藥？有冇敏感藥物？」「屋企人有冇皮膚敏感、濕疹、哮喘？」「你做邊行㗎？」 | Atopic tendency, drug causes (antibiotics → candidiasis), occupation (wet work → ICD) |
| 3:45–4:30 | ICE — uncover hidden agenda | 「你自己覺得係乜嘢原因呢？」(Ideas) 「你最擔心啲乜嘢？」(Concerns) 「你今日最希望我可以點樣幫到你？」(Expectations) 「點解揀咗今日嚟睇？」(Why today — hidden agenda) | ICE marks are high-yield. "Why today?" exposes trigger: e.g. fear of STI, cancer, relationship stress |
| 4:30–5:15 | Impact on daily life + psychological screening | 「呢個問題有冇影響到你瞓覺、返工、或者同伴侶嘅關係？」「你心情點呀？有冇覺得好煩或者好低落？」 | Biopsychosocial scoring; functional impact = social problem |
| 5:15–5:45 | Summarise back to patient | 「等我同你總結返：你嘅情況係⋯⋯我有冇聽漏咗乜嘢？」 | Checking understanding + summarising = marks |
| 5:45–6:00 | Closing: plan + safety net | 「我想幫你安排檢查同埋處方藥膏。如果情況惡化、發燒、或者有損爛，記住即刻返嚟。」 | Safe close with safety-net advice |
Hidden agenda tip: A patient with vulvar irritation may actually fear an STI (new partner, partner infidelity), cancer (seen a lump), or be embarrassed about hygiene. The question 「點解揀咗今日嚟睇？」 is essential.
| Domain | English Question | Cantonese Question | Why It Matters | If Positive, Think Of |
|---|---|---|---|---|
| Onset/Duration | When did it start? Acute or gradual? | 「幾時開始㗎？突然定係慢慢嚟？」 | Acute → contact/irritant/candida; Chronic → lichen simplex/lichen sclerosus | Acute: ICD, candidiasis; Chronic: lichen sclerosus |
| Site/Distribution | Exactly where? Labia, perineum, perianal? | 「主要邊度？大陰唇、小陰唇、定係周圍都有？」 | Distribution guides diagnosis | Perianal spread → psoriasis, lichen sclerosus |
| Character | Itch, burning, pain, dryness, discharge? | 「痕定痛？有冇乾、紅、或者損爛？有冇嘢流出嚟？」 | Itch → eczema/candida/lichen; Burning → ICD; Pain/ulcer → HSV, VIN | Burning + well-demarcated → contact dermatitis |
| Discharge | Any discharge? Colour, smell, consistency? | 「有冇白色或者其他顏色嘅分泌物？有冇味？」 | White curd → candida; fishy → BV; purulent → STI | Candidiasis, bacterial vaginosis, trichomonas |
| New exposures | New soap, pad, detergent, underwear, condom, lubricant, TTCM? | 「最近有冇轉用新嘅清潔液、衛生巾、底褲、潤滑劑、或者搽過中藥膏？」 | Contact dermatitis is a key DDx — must ask about new exposures [1][2] | Allergic contact dermatitis (ACD), irritant contact dermatitis (ICD) |
| Aggravating/Relieving | Worse with sweat, tight clothes, menstruation? Better with anything? | 「著緊身褲、出汗、或者嚟M嗰陣會唔會差啲？有冇嘢令佢好啲？」 | Heat/occlusion worsens candida & ICD | Candidiasis, intertrigo |
| Sexual Hx | Sexually active? New partner? Condom use? | 「我需要問啲比較私人嘅嘢——你有冇性行為？有冇新伴侶？有冇用安全套？」 | STI screen; genital herpes, condylomata | HSV, HPV/condylomata, syphilis |
| Menstrual/Obstetric | LMP? Menopausal? Pregnant? | 「你最後一次嚟M幾時？有冇停經？有冇可能懷孕？」 | Menopause → vulvovaginal atrophy/lichen sclerosus; pregnancy → candida | Atrophic vulvovaginitis, lichen sclerosus |
| Urinary Sx | Dysuria, frequency? | 「有冇痛尿、尿急、尿頻？」 | UTI co-exists; urine contact worsens ICD | Incontinence-associated dermatitis |
| Treatments tried | Any OTC cream, steroid, antifungal? | 「你之前有冇自己買藥膏搽？用過類固醇？去黴菌藥？」 | Steroid overuse → tinea incognito; treatment failure narrows DDx | Tinea incognito if steroids used |
| Past Hx | DM, immunosuppression, eczema, psoriasis? | 「你有冇糖尿病、濕疹、牛皮癬、或者免疫力低嘅病？」 | DM → recurrent candida; atopy → eczema | Recurrent candidiasis, vulvar psoriasis |
| Drug Hx | Antibiotics recently? Immunosuppressants? | 「最近有冇食過抗生素或者其他藥？」 | Antibiotics → candidiasis | Candidiasis |
| Allergy | Known drug/material allergies? | 「你有冇藥物或者材料敏感？」 | Latex allergy → condom ACD | ACD |
| FHx | Family atopy? Psoriasis? | 「屋企人有冇濕疹、哮喘、鼻敏感、牛皮癬？」 | Atopic tendency is key for atopic dermatitis diagnosis [3] | Atopic dermatitis |
| Occupation | Type of work? Wet-work, chemical exposure? | 「你做邊行㗎？要唔要成日接觸水或者化學品？」 | Wet work and chemicals are RFs for ICD [4] | ICD |
| Functional impact | Sleep disturbance, sex life affected, mood? | 「有冇影響你瞓覺、性生活、或者心情？」 | Biopsychosocial assessment | Depression, relationship strain |
| Red flags | Ulceration, bleeding, non-healing lesion, weight loss? | 「有冇損爛唔埋口、出血、體重輕咗？」 | Vulvar malignancy (VIN/SCC) | Vulvar intraepithelial neoplasia, SCC |
Case Report Form Answer Builder
- CC: Vulvar itch/irritation for [duration]
- HPI high-yield points to capture:
- Onset, duration, course (acute vs chronic/relapsing)
- Exact site (labia majora/minora, perineum, perianal)
- Character: itch, burning, pain, dryness
- Associated discharge (colour, consistency, odour)
- Aggravating factors: soap, pads, tight clothing, sweat, menstruation
- Relieving factors: treatments tried (OTC antifungals, steroids)
- New exposures: products, sexual contacts
- Red flags: ulceration, bleeding, non-healing lesion
- Sexual Hx, LMP/menopausal status, DM/immunosuppression
- Impact on sleep, function, relationships
- Likely RFC examples:
- "Patient presents with persistent vulvar itch not responding to OTC treatment"
- "Patient concerned about possible STI after new sexual contact"
- "Recurrent vulvar itch causing significant sleep disturbance and distress"
- How to phrase: State the patient's reason, not the diagnosis. Use one sentence linking symptom + trigger for attendance.
| Likely Content | Exact Wording to Write | |
|---|---|---|
| Ideas | "I think it might be a fungal infection" / "Maybe I'm allergic to something" / "Could it be an STI?" | "Patient thinks it may be a yeast infection / allergy to new sanitary pads" |
| Concerns | Fear of STI, cancer, infertility, embarrassment | "Patient is worried it could be sexually transmitted / something serious like cancer" |
| Expectations | Wants cream/treatment, wants STI test, wants referral to gynae | "Patient hopes to receive effective treatment and be reassured it is not serious" |
- Irritant contact dermatitis (if Hx of new product exposure + burning + well-demarcated reaction at contact site)
- Vulvovaginal candidiasis (if white curd discharge + itch + risk factors)
- Atopic dermatitis of vulva (if atopic tendency + chronic relapsing itch + lichenification)
- How to choose: Match symptom pattern to Hx. In an FM station, candidiasis or irritant contact dermatitis are the most common setups.
- Minimum supporting evidence: CC + characteristic features + risk factors + absence of red flags
| DDx | One Key Discriminator |
|---|---|
| 1. Allergic contact dermatitis | Crescendo patch-test reaction; requires prior sensitisation [6]; improvement on allergen avoidance |
| 2. Vulvar psoriasis | Well-demarcated erythematous plaques; Hx of psoriasis elsewhere; nail pitting |
| 3. Lichen sclerosus | White atrophic "figure-of-8" patches; postmenopausal; dyspareunia; risk of malignant change |
| Domain | Problem |
|---|---|
| Biological | Chronic vulvar dermatitis causing skin damage, secondary infection risk, and sleep disruption from itch |
| Psychological | Anxiety/embarrassment about genital symptoms; fear of STI or cancer; possible low mood from chronic itch |
| Social/Functional | Impact on sexual relationship / intimacy; avoidance of exercise/swimming; work absenteeism if severe |
| Diagnosis/DDx | Best Supporting Physical Sign | How to Elicit | Why It Supports This Diagnosis |
|---|---|---|---|
| Irritant contact dermatitis (most likely) | Erythematous, dry, fissured skin localised to area of irritant contact (e.g., pad area) with sharp demarcation [4][5] | Visual inspection of vulva; note distribution matches contact area; ask patient to show product used | Reaction limited to contact site = hallmark of exogenous dermatitis |
| Vulvovaginal candidiasis | Vulvar erythema + white curd-like ("cottage cheese") discharge adherent to vaginal walls; pseudohyphae on wet mount (KOH prep) [7] | Speculum exam; take vaginal swab for KOH prep / wet mount | Pathognomonic discharge pattern + microscopy finding |
| Allergic contact dermatitis | Erythematous indurated plaque that may extend beyond contact site; positive patch test (crescendo reaction at D4) [6] | Inspect vulva; arrange patch testing with suspected allergens | Spread beyond contact area + crescendo on patch test distinguishes from ICD |
| Vulvar psoriasis | Well-demarcated, erythematous, non-scaly plaques (inverse psoriasis pattern); check extensor surfaces, scalp, nails for psoriatic changes elsewhere | Inspect vulva + full skin exam including nails, elbows, knees, scalp | Inverse (flexural) psoriasis lacks silvery scale; finding psoriasis elsewhere clinches diagnosis |
| Lichen sclerosus | Porcelain-white atrophic patches in "figure-of-8" distribution (vulva + perianal) ± purpura, fissures, labial fusion | Visual inspection under good light | Pathognomonic appearance; important because of SCC risk (4–5%) |
| Genital herpes (HSV) | Grouped vesicles on erythematous base → shallow painful ulcers; inguinal lymphadenopathy | Visual inspection; swab for HSV PCR | Grouped vesicles + pain is classic; no reliable bedside physical sign in healed phase — need viral PCR |
| VIN/SCC | Persistent raised plaque/ulcer, irregular border, may be pigmented or leukoplakic; non-tender | Visual inspection; any suspicious lesion requires biopsy | Non-healing vulvar lesion in older/immunosuppressed patient → must biopsy to rule out malignancy |
Exam Discriminators and Traps
Top Traps That Lose Marks
- Forgetting to ask about new product exposures — contact dermatitis (ICD/ACD) is a top DDx and examiners expect it
- Not asking sexual history — you WILL lose marks; always seek permission first, then ask directly
- Assuming all vulvar itch = candida — lichen sclerosus, psoriasis, dermatitis, and VIN are commonly missed
- Not asking about menopausal status — vulvovaginal atrophy and lichen sclerosus are postmenopausal diagnoses
- Writing "vaginal discharge" as CC when the patient says "itch/irritation" — use the patient's own words
- Forgetting to explore ICE — the hidden concern (STI? cancer?) is often the real reason for consultation
- Missing the red flag of a non-healing vulvar ulcer — must refer urgently for biopsy to exclude VIN/SCC
| Red Flag | Think Of | Action |
|---|---|---|
| Non-healing vulvar ulcer or plaque > 2 weeks | VIN / vulvar SCC | Urgent gynaecology/dermatology referral for biopsy |
| Painful vesicles/ulcers + systemic symptoms | Primary genital herpes | Confirm with HSV PCR; start aciclovir ASAP |
| Progressive white atrophic change with labial fusion | Lichen sclerosus | Referral for biopsy + potent topical steroid; long-term follow-up (SCC risk) |
| Recurrent candidiasis (≥ 4/year) | Undiagnosed DM, immunodeficiency | Check fasting glucose/HbA1c, HIV test |
「如果我哋考慮係刺激性皮炎，最緊要先停用嗰啲刺激嘅嘢，用溫和嘅清潔劑，搽潤膚膏。我會開支弱效類固醇藥膏俾你。如果兩個禮拜都冇好轉，或者有損爛、出血、發燒，一定要返嚟覆診。」
(If we think this is irritant dermatitis: stop the irritant, use gentle cleanser, apply emollient. I'll prescribe a mild topical steroid. If no improvement in 2 weeks, or if ulceration/bleeding/fever develops, come back immediately.)
High Yield Summary
What to ASK: Onset/duration, exact site, itch vs burning, discharge, new product exposure, sexual Hx (with permission), LMP/menopause, DM, atopic Hx, treatments tried, red flags (ulcer/bleeding), ICE + "why today?"
What to WRITE: CC in patient's words → structured HPI → RFC as ONE sentence linking symptom + trigger → ICE verbatim → Most likely Dx with evidence → 3 DDx with discriminators → 3 biopsychosocial problems → 1 physical sign with how/why
What NOT TO MISS: Non-healing vulvar ulcer (VIN/SCC); lichen sclerosus (white atrophy, SCC risk); recurrent candida (screen DM); contact dermatitis history (product change); hidden STI fear; sexual Hx
Active Recall - Family Medicine Clinical Test
[1] GC 065. I have an itchy rash.pdf (slide on Management of dermatitis: History - duration, site, occ, atopic tendency, FH) [2] Block A - I have an itchy rash (eczema, urticaria, tinea infection and psoriasis).pdf (Case 3-4: exogenous dermatitis, contact dermatitis from TTCM) [3] Adrian Lui Pediatrics Notes.pdf (p402: atopic dermatitis RFs — FHx of atopic disease 70%) [4] Ryan Ho Rheumatology.pdf (p118: Irritant contact dermatitis — RFs including wet work, chemical irritants) [5] Derm General Clerkship 2026 Part1.pdf (p20: ICD 80% of cases, ACD 20%) [6] Immunology- Fundamentals of allergology.pdf (p52: patch test crescendo vs decrescendo reactions) [7] Block C - Vaginal discharge_ obstetric and gynaecological infections.pdf (p12: Candida wet mount — pseudohyphae)
Visual Loss (gradual)
Gradual visual loss is a progressive decline in visual acuity or visual field occurring over weeks to years, commonly caused by conditions such as cataracts, glaucoma, age-related macular degeneration, diabetic retinopathy, or refractive errors.
Weight Gain
An increase in body weight over time, resulting from excess caloric intake, fluid retention, increased muscle mass, or underlying medical conditions such as hypothyroidism or Cushing syndrome.