Dermatology Tools for Clinicians

Calculators, severity scales, diagnostic guides and classifications — built for dermatologists worldwide, free for everyone.

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Browse by disease using the A–Z menu on the left (or tap the ☰ button on mobile). Select a disease to see its available tools — calculators, severity scales and clinical guides — each clearly labelled by type.

Available now

Acne3

Isotretinoin Dose Calculator

Plan cumulative dose targets with custom phases and track ongoing treatment progress.

PCOS Diagnostic Guide

Interactive diagnostic algorithm for polycystic ovary syndrome with phenotype classification, based on the 2023 guideline.

GAGS Calculator

Global Acne Grading System — six weighted locations graded by predominant lesion type, total 0–44 with severity bands.

Alopecia Areata1

Scale Alopecia Areata

Severity of Alopecia Tool — weighted scalp hair loss (0–100) with Olsen S bands and SALT ≤20 / SALT50-75-90 response thresholds.

Androgenetic Alopecia1

Guide Androgenetic Alopecia

FPHL Classification

Female pattern hair loss: Ludwig I–III, Sinclair 1–5 and Olsen (Christmas-tree) pattern in one descriptive guide.

Atopic Dermatitis2

Scale Atopic Dermatitis

Severity scoring of atopic dermatitis — extent, intensity and symptoms.

Scale Atopic Dermatitis

EASI Calculator

Eczema Area and Severity Index — four body regions scored for clinical signs and extent.

Bullous Pemphigoid1

Scale Bullous Pemphigoid

Bullous Pemphigoid Disease Area Index — blisters/erosions, urticaria/erythema, mucosa, damage and pruritus VAS with validated cut-offs.

Chronic Urticaria1

Scale Chronic Urticaria

Urticaria Activity Score over 7 days (wheals + itch, 0–42) with activity bands, and the Urticaria Control Test (0–16).

Cutaneous Squamous Cell Carcinoma1

Guide Cutaneous Squamous Cell Carcinoma

cSCC Staging Guide

AJCC 8th edition and Brigham and Women's Hospital T classification of primary cutaneous squamous cell carcinoma.

Dermatomyositis2

Scale Dermatomyositis

Cutaneous Dermatomyositis Disease Area and Severity Index — activity and damage scoring of dermatomyositis skin disease.

Guide Dermatomyositis

EULAR/ACR 2017 Myositis Criteria

Probability-based classification of idiopathic inflammatory myopathies with subclassification into DM, ADM, PM, IBM and JDM.

Drug Reactions / Toxicoderma2

Scale Drug Reactions / Toxicoderma

Naranjo ADR Scale

Adverse drug reaction probability scale: 10 weighted questions classify causality as definite, probable, possible or doubtful.

Scale Drug Reactions / Toxicoderma

RegiSCAR DRESS Score

RegiSCAR validation score for DRESS: classifies a suspected case as no case, possible, probable or definite.

Frontal Fibrosing Alopecia1

Scale Frontal Fibrosing Alopecia

FFASI Calculator

Frontal Fibrosing Alopecia Severity Index — hairline recession, frontal band, non-scalp hair loss and associated lichen planus features (0–100).

Hand Eczema1

Scale Hand Eczema

HECSI Calculator

Hand Eczema Severity Index — six signs and extent in five hand areas (0–360) with Oosterhaven 2020 severity strata.

Hidradenitis Suppurativa4

Scale Hidradenitis Suppurativa

IHS4 Calculator

Dynamic hidradenitis suppurativa severity scoring using weighted lesion counts.

Scale Hidradenitis Suppurativa

Refined Hurley Staging

Interactive 7-stage HS classification guiding medical and surgical treatment decisions.

Scale Hidradenitis Suppurativa

HiSCR Calculator

Hidradenitis Suppurativa Clinical Response — treatment response criterion used in clinical trials.

Scale Hidradenitis Suppurativa

Modified Sartorius Score (mSS)

Region-by-region HS severity score — best suited for tracking change over time.

Hirsutism / PCOS1

Scale Hirsutism / PCOS

Modified Ferriman-Gallwey Score

Hirsutism score over 9 body areas (0–36) with population-specific cut-offs and AE-PCOS severity bands.

Lichen Planopilaris1

Scale Lichen Planopilaris

LPPAI Calculator

Lichen Planopilaris Activity Index — symptoms, signs, anagen pull test and spreading combined into a 0–10 activity score.

Lupus erythematosus2

Scale Lupus erythematosus

Cutaneous Lupus Erythematosus Disease Area and Severity Index — activity and damage scoring of cutaneous lupus.

Guide Lupus erythematosus

EULAR/ACR 2019 SLE Criteria

Weighted classification criteria for systemic lupus erythematosus — ANA entry criterion, 10 domains, ≥ 10 points.

Morphea1

LoSCAT (mLoSSI / LoSDI)

Localized Scleroderma Cutaneous Assessment Tool — morphea activity (mLoSSI) and damage (LoSDI) over 18 sites.

Mucous Membrane Pemphigoid1

Scale Mucous Membrane Pemphigoid

Mucous Membrane Pemphigoid Disease Area Index — ocular, oral and other mucosal, skin and scalp activity plus damage (2015 consensus).

Pemphigus2

Scale Pemphigus

Autoimmune Bullous Skin Disorder Intensity Score — weighted skin extent, oral sites and eating/drinking discomfort.

Scale Pemphigus

Pemphigus Disease Area Index — skin, scalp and mucosal activity plus damage, with published severity cut-offs.

Psoriasis2

Scale Psoriasis

Nail Psoriasis Severity Index — matrix and nail bed signs by quadrant for each nail (0–80 or 0–160).

Scale Psoriasis

Quality of life1

Scale Quality of life

DLQI Calculator

Dermatology Life Quality Index: 10-item patient questionnaire scored 0–30 with severity bands.

Systemic sclerosis1

Scale Systemic sclerosis

Modified Rodnan Skin Score

Skin thickness in systemic sclerosis — 17 sites scored 0–3 by palpation (max 51), standardised technique.

Vitiligo2

VASI Calculator

Vitiligo Area Scoring Index — hand units × residual depigmentation per region; total and facial (F-VASI) scores.

Vitiligo Disease Activity score: six-point grading of activity (+4 to −1) from the time since last progression.