Dermatology Calculators
22 calculators & risk scores
Browse 22 Dermatology clinical calculators and risk scores used in everyday UK practice. Every tool runs entirely in your browser — enter the values and get instant scoring, colour-coded interpretation bands and a link to the underlying guideline or publication. ClinCalc Pro is free, needs no sign-up, and is built for working clinicians.
These dermatology tools span Formula, Diagnosis, Prognosis, Melanoma, Urticaria, Scar Assessment and more.
- TBSA — Total Body Surface Area Burned (Rule of Nines)Wallace Rule of Nines (adult proportions) for estimating the total body surface area of partial- and full-thickness burns. In children use a Lund and Browder chart — head and limb proportions change with age. Guides fluid resuscitation and transfer criteria.
- PASI — Psoriasis Area and Severity IndexStandard severity scoring for plaque psoriasis. PASI ≥10 typically indicates moderate-to-severe disease requiring systemic treatment.
- DLQI — Dermatology Life Quality Index10-item patient-reported outcome measure for quality of life in skin conditions. Combined with PASI to assess biologic eligibility.
- Melanoma ABCDE CriteriaABCDE (Asymmetry, Border irregularity, Colour variation, Diameter > 6 mm, Evolving) is a recognition aid for melanoma (Friedman 1985; E added by Abbasi 2004), not a validated score — an evolving lesion is suspicious on its own. In the UK, NICE NG12 refers a suspicious pigmented lesion on a suspected cancer pathway when the weighted 7-point checklist scores 3 or more, or when dermoscopy suggests melanoma.
- EASI — Eczema Area and Severity IndexValidated severity score for atopic dermatitis (eczema) used to assess treatment response and biologic eligibility.
- SCORTEN — Severity Score for TEN/SJSSeverity-of-illness score for toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) to predict mortality.
- Breslow Thickness & Melanoma StagingBreslow thickness is the primary determinant of melanoma T-stage and sentinel lymph node biopsy eligibility. Based on AJCC 8th edition staging.
- Urticaria Activity Score (UAS7)7-day urticaria activity score assessing wheals and pruritus, used to guide antihistamine dosing and omalizumab eligibility in chronic spontaneous urticaria (CSU).
- Vancouver Scar Scale (VSS)4-item clinical scar assessment tool evaluating vascularity, pigmentation, pliability, and height. Total score 0–13; higher score = worse scar. Used to assess burn scars, surgical scars, and response to treatment (silicone gel, pressure garments, laser therapy).
- Melanoma Breslow Thickness and StagingGives the AJCC 8th edition pathological T category of a cutaneous melanoma from Breslow thickness and ulceration (mitotic rate is no longer a T criterion). Guides excision margin and sentinel lymph node biopsy (SLNB) decisions (NICE NG14).
- PASI Score (Psoriasis Area and Severity Index)Quantifies psoriasis severity by assessing extent and intensity across four body regions. PASI >=10 defines moderate-severe psoriasis eligible for systemic therapy.
- DLQI (Dermatology Life Quality Index)Dermatology Life Quality Index (Finlay & Khan 1994): 10 questions about the last week, each scored 0–3, total 0–30. DLQI > 10 = very large effect; with PASI ≥ 10 it defines severe psoriasis for NICE biologic eligibility.
- EASI Score (Eczema Area and Severity Index)Quantifies atopic dermatitis severity across four body regions (0–72; region weights differ under 8 years). Severity strata per Leshem 2015; used to assess treatment response and eligibility for systemic treatment.
- RegiSCAR Score for DRESSValidates a suspected case of drug reaction with eosinophilia and systemic symptoms (DRESS) with the RegiSCAR scoring system (Kardaun 2007): total −4 to 9; < 2 no case, 2–3 possible, 4–5 probable, > 5 definite.
- Acne Severity Classification (IGA Scale)Grades acne vulgaris with the Investigator's Global Assessment (IGA). NICE NG198 grades severity by lesion count: mild to moderate = up to 34 inflammatory lesions and up to 2 nodules; moderate to severe = 35 or more inflammatory lesions or 3 or more nodules.
- VIDA Score (Vitiligo Disease Activity)Assesses disease activity in vitiligo using the Vitiligo Disease Activity (VIDA) score. Guides treatment selection (immunosuppression vs phototherapy vs surgical).
- Lund-Browder Chart — TBSA Burn EstimationAge-adjusted body-surface chart for estimating second- and third-degree burn TBSA. More accurate than Rule of Nines, particularly in children where the head accounts for a disproportionately large surface area. Use the resulting TBSA% with the Parkland formula for fluid resuscitation.
- SCORAD — SCORing Atopic DermatitisEuropean Task Force on Atopic Dermatitis severity index. Total = A/5 + 7B/2 + C, where A = extent (0–100% TBSA), B = sum of 6 intensity items (each 0–3, max 18), C = subjective pruritus + sleep loss VAS (0–20). Pick severity band below — or compute the formula manually.
- POEM — Patient-Oriented Eczema Measure7-item patient/parent-reported atopic eczema symptom score (Charman 2004). Each item 0–4 (days in past week). Total 0–28. Recommended core outcome by HOME initiative.
- Hurley Staging for Hidradenitis SuppurativaThree-stage clinical classification of hidradenitis suppurativa (Hurley 1989). Drives initial therapeutic stratification per BAD 2018 guidelines.
- Sartorius Score for Hidradenitis SuppurativaThe modified Sartorius score (Sartorius 2009) adds points region by region for each involved region, nodules, fistulas, scars and other lesions, the longest distance between two lesions, and Hurley III involvement. It tracks change between visits but has no validated mild / moderate / severe cut-offs.
- MASI — Melasma Area and Severity IndexMelasma Area and Severity Index (Kimbrough-Green 1994): area (0–6), darkness (0–4) and homogeneity (0–4) in four facial regions — forehead 30 %, right malar 30 %, left malar 30 %, chin 10 %. Total 0–48. The modified MASI (Pandya 2011) drops homogeneity (0–24). Used in trials to track response.