Patient guide · Terminology
Dermatology terms
in plain English
Make sense of your chart, your diagnosis slip and the articles here. Terms are grouped by "scales / mechanisms / drugs / disease subtypes / investigations", each with a plain-language explanation and a link to the relevant article.
1 · Clinical scales / assessment tools
Scale
SCORAD
Severity Scoring of Atopic Dermatitis
Atopic dermatitis severity score. Combines area + objective signs (erythema, oedema, oozing, excoriation, lichenification, dryness) + subjective symptoms (itch, sleep loss), 0-103. <25 mild, 25-50 moderate, >50 severe.
SCORAD calculator →Scale
PASI
Psoriasis Area and Severity Index
Psoriasis severity. Head/neck, upper limbs, trunk and lower limbs scored for erythema + induration + scaling + area, weighted, 0-72. Taiwan NHI biologic threshold is PASI ≥ 10.
PASI calculator →Scale
DLQI
Dermatology Life Quality Index
Dermatology Life Quality Index, 10 self-rated items, 0-30. A common NHI biologic threshold is DLQI ≥ 10.
DLQI calculator →Scale
UAS7
Urticaria Activity Score over 7 days
Urticaria activity. Daily wheal count and itch, each 0-3, summed over 7 consecutive days, 0-42. Target is ≤ 6.
UAS7 calculator →Scale
UCT
Urticaria Control Test
Urticaria Control Test, 4 quick items. 16 = complete control, 12-15 = partial control, < 12 = poorly controlled.
Urticaria article →Scale
SALT
Severity of Alopecia Tool
Percentage of scalp hair lost in alopecia areata. Vertex (40%) + occiput (24%) + left (18%) + right (18%). SALT ≥ 50 is severe and an indication for JAK inhibitors.
SALT calculator →Scale
GAGS
Global Acne Grading System
Global Acne Grading System. Six sites × lesion-severity weights, 0-44. ≥ 31 is severe and an indication for isotretinoin.
GAGS calculator →Scale
MASI
Melasma Area & Severity Index
Melasma severity. Forehead, both cheeks and chin scored as area × (darkness + homogeneity), weighted, 0-48.
MASI calculator →Scale
Hurley staging
Hurley Staging (HS)
Hidradenitis suppurativa (HS) graded stage I / II / III. Stage II and above is the reference point for adalimumab under Taiwan NHI.
Hurley staging guide →Scale
Norwood-Hamilton / Ludwig
Male / Female Pattern Hair Loss Scale
Androgenetic alopecia graded Norwood I-VII in men, Ludwig I-III in women. The more advanced, the more aggressive the treatment (finasteride, hair transplant).
Grading calculator →Scale
Fitzpatrick skin type
Fitzpatrick Skin Type
Skin phototypes I-VI. Most Asians are type III-IV, prone to post-inflammatory hyperpigmentation after laser or chemical peels, so strict photoprotection matters.
Fitzpatrick calculator →Scale
EASI
Eczema Area & Severity Index
The other widely used AD measure, an alternative to SCORAD. EASI 75 / 90 / 100 mean ≥75% / 90% / 100% improvement.
Atopic dermatitis article →Scale
IGA-PN
Investigator's Global Assessment for Prurigo Nodularis
Investigator Global Assessment for prurigo nodularis, 0-4. 0 = clear, 1 = almost clear (the treatment target).
Prurigo nodularis article →Scale
WI-NRS
Worst Itch Numeric Rating Scale
Worst itch in the past 24 hours, 0-10. A drop of ≥ 4 points is a clinically meaningful response.
Prurigo nodularis article →Scale
VIDA
Vitiligo Disease Activity
Vitiligo disease activity. VIDA ≥ +2 means active disease needing systemic suppression; VIDA ≤ 0 for ≥ 1 year means stable and suitable for surgery.
Vitiligo article →Scale
TNMB staging
TNMB staging (CTCL)
Staging for cutaneous T-cell lymphoma (MF/SS). T (skin) + N (nodes) + M (viscera) + B (blood). B2 ≥ 1000/μL is automatically Sézary syndrome.
CTCL article →2 · Mechanisms / cytokines
Mechanism
IL-4 / IL-13
Interleukin 4/13 (Th2)
The core inflammatory cytokines of atopic dermatitis, allergic asthma and CRSwNP. Dupilumab blocks IL-4Rα, switching off IL-4 and IL-13 signalling together.
Atopic dermatitis article →Mechanism
IL-17 / IL-23
Interleukin 17 / 23 (Th17)
The main drivers of psoriasis, psoriatic arthritis and hidradenitis suppurativa. Secukinumab / bimekizumab target IL-17; risankizumab / guselkumab target IL-23.
Psoriasis article →Mechanism
IL-31
Interleukin 31 (itch cytokine)
The "itch cytokine". Highly active in prurigo nodularis and atopic dermatitis. Blocking IL-31R with nemolizumab improves itch markedly within 1-2 weeks.
Prurigo nodularis article →Mechanism
JAK / STAT pathway
Janus Kinase / STAT pathway
The intracellular signalling pathway downstream of cytokine receptors. JAK1-3 + TYK2. JAK inhibitors (baricitinib, upadacitinib, abrocitinib, ritlecitinib) block it.
Biologics article →Mechanism
TNF-α
Tumor Necrosis Factor-α
A central cytokine of chronic inflammation. Adalimumab, etanercept, infliximab and certolizumab are TNF-α inhibitors, used in psoriasis, HS, PsA and IBD.
Biologics article →Mechanism
PIH / PIE
Post-inflammatory Hyperpigmentation / Erythema
Post-inflammatory hyperpigmentation (PIH, brown-black) or erythema (PIE, red). PIH risk is high in Asian skin and common after laser or acne.
Melasma article →Mechanism
Koebner phenomenon
Koebner phenomenon
New lesions appear at sites of injury, friction or scratching. Typical of vitiligo, psoriasis and lichen planus. Vitiligo must be stable for a year before grafting is appropriate.
Vitiligo article →Mechanism
Th1 / Th2 / Th17
T helper 1/2/17 cells
Helper T-cell subsets: Th1 = cellular immunity (defence against infection), Th2 = allergy / atopic dermatitis, Th17 = psoriasis / HS / PsA.
Biologics article →3 · Key drugs
Drug
Dupilumab (Dupixent)
anti-IL-4Rα mAb
The first broad-spectrum biologic in dermatology. FDA indications: atopic dermatitis from 6 months of age, prurigo nodularis, asthma, CRSwNP, eosinophilic oesophagitis. One injection every 2 weeks.
How it is used →Drug
Nemolizumab(2024 FDA)
anti-IL-31R mAb
The 2024 FDA-approved biologic specifically for prurigo nodularis. One injection every 4 weeks (fewer injections than dupilumab).
How it is used →Drug
Omalizumab (Xolair)
anti-IgE mAb
Second line for chronic spontaneous urticaria (CSU). 300 mg q4w, and if the response is poor it can be escalated to 600 mg q2w (off-label).
How it is used →Drug
Baricitinib (Olumiant)
JAK 1/2 inhibitor
The first FDA/EMA-approved oral JAK inhibitor for alopecia areata (severe disease in adults); also used in atopic dermatitis and rheumatoid arthritis.
How it is used →Drug
Ritlecitinib (Litfulo)
JAK 3 / TEC inhibitor
Indicated for alopecia areata from age 12. 200 mg/day for 4 weeks as loading, then 50 mg/day maintenance.
How it is used →Drug
Risankizumab (Skyrizi)
anti-IL-23 p19 mAb
A biologic for psoriasis, PsA and Crohn's disease. One injection every 12 weeks — the longest dosing interval of the class. Conditionally covered by Taiwan NHI.
How it is used →Drug
Bimekizumab(Bimzelx)
anti-IL-17A/F mAb
Dual IL-17 inhibition (A + F). The biologic with the highest PASI 100 rate in psoriasis (over 60% at 16 weeks).
How it is used →Drug
Deucravacitinib(Sotyktu)
selective TYK2 inhibitor
The first selective TYK2 inhibitor taken orally for psoriasis. A better safety profile than classic JAK1-3 inhibitors, with no ORAL Surveillance warning.
How it is used →Drug
Brentuximab vedotin (Adcetris)
anti-CD30 ADC
For CD30+ cutaneous T-cell lymphoma (MF / pcALCL). ALCANZA trial: ORR4 56% vs 13%.
CTCL regimen →Drug
Mogamulizumab(Poteligeo)
anti-CCR4 mAb
Sézary syndrome and advanced MF. MAVORIC trial: median PFS 7.7 vs 3.1 months.
CTCL regimen →Drug
Ruxolitinib 1.5% cream(Opzelura)
topical JAK 1/2 inhibitor
The 2022 FDA-approved topical for vitiligo (age ≥ 12, non-segmental, ≤ 10% body surface). Half of patients reached F-VASI 75 by 52 weeks.
Vitiligo regimen →Drug
Clascoterone(Winlevi)
topical androgen receptor antagonist
The 2020 FDA-approved topical antiandrogen for acne — the first topical acne drug with a new mechanism in 40 years.
Acne regimen →Drug
Low-dose oral minoxidil (LDOM)
low-dose oral minoxidil
Doses of ≤ 5 mg/day, below the blood-pressure-lowering range. Women 1.25-2.5 mg, men 2.5-5 mg (Olsen 2025 JAAD consensus).
How it is used →4 · Disease subtypes
Subtype
Mycosis Fungoides(MF)
Mycosis fungoides
The commonest cutaneous T-cell lymphoma, about 75% of cases. Three stages: patch → plaque → tumour.
CTCL article →Subtype
Sézary Syndrome(SS)
Erythrodermic CTCL
MF with erythroderma plus blood involvement by T cells. ≥ 80% BSA erythema + Sézary cells ≥ 1000/μL. Prognosis is poorer.
CTCL article →Subtype
CSU
Chronic Spontaneous Urticaria
Chronic spontaneous urticaria (wheals for ≥ 6 weeks with no external trigger). Half remit spontaneously within a year, 80% within five.
Urticaria article →Subtype
SV / NSV
Segmental / Non-Segmental Vitiligo
Segmental (SV) versus non-segmental (NSV) vitiligo. SV has the better prognosis and suits surgery; NSV responds well to ruxolitinib.
Vitiligo article →Subtype
The four rosacea phenotypes
Rosacea phenotypes (Clanner 2022)
Phenotype-based classification, replacing the old subtypes I-IV: persistent erythema, papules and pustules, telangiectasia, phyma. Ocular rosacea is a comorbidity.
Rosacea article →5 · Investigations / procedures
Procedure
Skin biopsy with immunohistochemistry
Skin biopsy + IHC
For suspected CTCL, bullous disease or lupus erythematosus. Common IHC markers: CD3/CD4/CD8/CD30/CD20.
CTCL article →Procedure
TCR gene rearrangement
T-cell Receptor gene rearrangement
Testing a skin biopsy for T-cell monoclonality. Essential to diagnosing MF early.
CTCL article →Procedure
Wood's lamp / dermoscopy
Wood lamp / Dermoscopy
Wood's lamp: non-invasive illumination; vitiligo appears brighter, tinea versicolor fluoresces yellow-green. Dermoscopy: 10× magnification to help diagnose naevi, melanoma and alopecia areata.
Vitiligo article →Procedure
NB-UVB phototherapy
Narrow-band UVB phototherapy
Narrowband 311-312 nm. The standard phototherapy for psoriasis, vitiligo, prurigo nodularis and widespread atopic dermatitis. Two to three sessions a week.
Psoriasis article →Procedure
308-nm excimer laser
308-nm Excimer laser
Targeted phototherapy for localised vitiligo, psoriasis and stubborn atopic dermatitis. Higher dose than NB-UVB over a shorter course.
Vitiligo article →Procedure
Intralesional corticosteroid injection
Intralesional corticosteroid (ILK)
Usually triamcinolone acetonide (TA) 5-10 mg/mL. The standard procedure for alopecia areata, hypertrophic scars and acne nodules. Every 4-6 weeks.
Alopecia areata article →6 · Common signs and symptoms
Sign
Lichenification
Lichenification
Chronic, repeated scratching thickens the skin, deepening the creases and making skin markings prominent. Typical of atopic dermatitis, prurigo nodularis and neurodermatitis.
Atopic dermatitis article →Sign
Blister
Vesicle / Bulla
A raised, fluid-filled lesion. < 0.5 cm = vesicle, ≥ 0.5 cm = bulla. Seen in dyshidrotic eczema, herpes simplex, chickenpox and autoimmune bullous disease.
Shingles article →Sign
Pustule
Pustule
A raised lesion containing pus (white or yellow). Seen in papulopustular rosacea, acne and folliculitis.
Rosacea article →Sign
Butterfly sign
Butterfly sign
A spared triangle in the upper mid-back, where the hands cannot reach. Characteristic of prurigo nodularis and chronic prurigo.
Prurigo nodularis article →Sign
Angioedema
Angioedema
Deep subcutaneous swelling, typically of the eyelids, lips, hands and feet. Around 40% of chronic urticaria patients have it. Laryngeal oedema is an emergency.
Urticaria article →Sign
Leonine facies
Leonine facies
Widespread infiltrative erythema and thickening of the face, giving a "lion-like" appearance. Seen in tumour-stage MF, leprosy and lymphoma.
CTCL article →Sign
Trichrome / confetti
Trichrome / Confetti
Markers of vitiligo activity. Trichrome: white centre → intermediate shade → normal skin; confetti: coalescing small white macules. Both predict rapid progression.
Vitiligo article →How to read this:本字典為衛教輔助工具。詞彙解釋以本站常用程度與病人實際遇到的情境設計、完整定義請參考各文章 / 學會共識。發現錯誤或希望新增詞彙、請email us。
Scale
PASI 75 / 90 / 100
PASI improvement endpoints
Psoriasis outcome measures. PASI 75 = at least 75% skin improvement at 16 weeks, PASI 90 ≥ 90%, PASI 100 = complete clearance. The old target was PASI 50-75; modern biologics have raised it to PASI 90/100.
Systemic psoriasis therapy →Scale
EASI / IGA
Eczema Area and Severity Index / Investigator Global Assessment
Atopic dermatitis severity (EASI 0-72; IGA 0-4). EASI 75/90 = ≥ 75%/90% improvement. Taiwan NHI threshold for dupilumab: EASI ≥ 24 and IGA ≥ 4.
Systemic AD therapy →Drug
Dupilumab (Dupixent®)
anti-IL-4Rα monoclonal antibody
The first FDA-approved biologic for atopic dermatitis, approved in 2017, blocking IL-4 and IL-13 signalling. Subcutaneous injection every 2 weeks, licensed from 6 months of age. Covered by Taiwan NHI at EASI ≥ 24 and IGA ≥ 4.
About dupilumab →Drug
JAK inhibitors
Janus kinase inhibitors
Oral targeted drugs blocking JAK1/2/3 signalling. For AD: abrocitinib and upadacitinib, reaching EASI 75 in 60-78%. FDA boxed warning: MACE, venous thromboembolism and malignancy; avoid from age 65.
JAK inhibitors →Drug
IL-23 inhibitors
IL-23 inhibitors
The newest generation of psoriasis biologics: risankizumab, guselkumab, tildrakizumab. Subcutaneous every 8-12 weeks, the lowest infection risk of the classes, and usable alongside IBD.
IL-23 inhibitors →Drug
IL-17 inhibitors
IL-17 inhibitors
The second generation of psoriasis biologics: secukinumab, ixekizumab, bimekizumab. Strong on nails, scalp and PsA. Contraindicated with IBD.
IL-17 inhibitors →Procedure
Skin biopsy
skin biopsy (shave / punch / incisional / excisional)
The key diagnostic tool in dermatology. Four techniques: shave (superficial), punch (4 mm, full thickness), incisional (part of a large lesion) and excisional (the whole lesion with a margin).
The four biopsy techniques →Procedure
Fusiform excision
fusiform / elliptical excision
The standard operation for excising a skin tumour. A 3:1 length-to-width ratio, apical angles ≤ 30°, long axis parallel to Langer's lines, so the scar sits under less tension.
The fusiform excision procedure →Disease
Psoriatic arthritis (PsA)
Psoriatic arthritis
Affects 15-30% of psoriasis patients, with skin disease usually preceding it by 5-10 years. Five red flags: morning stiffness > 30 minutes, dactylitis, enthesitis, inflammatory back pain, DIP arthritis. If positive → rheumatology, and biologics directly.
PsA comorbidity →