LoSCAT — mLoSSI and LoSDI

Localized Scleroderma Cutaneous Assessment Tool — Arkachaisri et al., 2009 (LoSSI) and 2010 (LoSCAT); severity bands Teske & Jacobe, 2020

Purpose
Physician-scored activity (mLoSSI) and damage (LoSDI) of morphea / localized scleroderma; the recommended skin score in the 2024 EDF/EADV consensus.
Population
Children and adults with any morphea subtype. In each of the 18 sites score the most representative lesion, recording the worst grade for each domain, compared with contralateral or adjacent unaffected skin.
Formula
mLoSSI (0–162) = Σ 18 sites [new lesion / extension 0 or 3 + erythema 0–3 + skin thickness 0–3]. LoSDI (0–162) = Σ 18 sites [dermal atrophy 0–3 + subcutaneous atrophy 0–3 + dyspigmentation 0–3].
Severity thresholds
Teske & Jacobe 2020 (MAC cohort): mLoSSI 0–4 mild · 5–12 moderate · ≥ 13 severe; LoSDI 0–10 mild · 11–15 moderate · ≥ 16 severe. Complete the LoSCAT with the physician global assessments of activity and damage (PGA-A, PGA-D, 0–100).
🔥 mLoSSI — 18 anatomical sites

Erythema is assessed at the lesion border; skin thickness by palpation against unaffected skin.

New lesion / lesion extension (N/E): 0 no · 3 a new lesion appeared or an existing lesion enlarged within the last month
Erythema (ER): 0 none · 1 pink / mild · 2 red / moderate · 3 dark red or violaceous / marked
Skin thickness (ST): 0 normal, freely mobile · 1 mild thickening, mobile · 2 moderate thickening, reduced mobility · 3 marked thickening, immobile (cannot be pinched)
mLoSSI total 0 / 162
🩹 LoSDI — 18 anatomical sites

Damage features of the most representative lesion in each site.

Dermal atrophy (DAT): 0 normal · 1 shiny skin · 2 visible vessels (or minimal "cliff-drop") · 3 obvious "cliff-drop" sign
Subcutaneous atrophy (SAT): 0 normal · 1 flattening (up to ⅓ fat loss) · 2 concave surface (⅓–⅔ fat loss) · 3 marked atrophy (> ⅔ fat loss)
Dyspigmentation (DP): 0 normal · 1 mild · 2 moderate · 3 marked hyper- or hypopigmentation
LoSDI total 0 / 162
📚 References
  1. Arkachaisri T, Vilaiyuk S, Li S, et al. The localized scleroderma skin severity index and physician global assessment of disease activity: a work in progress toward development of localized scleroderma outcome measures. J Rheumatol. 2009;36(12):2819–29.
  2. Arkachaisri T, Vilaiyuk S, Torok KS, Medsger TA Jr. Development and initial validation of the Localized Scleroderma Skin Damage Index and Physician Global Assessment of disease Damage: a proof-of-concept study. Rheumatology (Oxford). 2010;49(2):373–81.
  3. Kelsey CE, Torok KS. The Localized Scleroderma Cutaneous Assessment Tool: responsiveness to change in a pediatric clinical population. J Am Acad Dermatol. 2013;69(2):214–20.
  4. Teske NM, Jacobe HT. Using the Localized Scleroderma Cutaneous Assessment Tool (LoSCAT) to classify morphoea by severity and identify clinically significant change. Br J Dermatol. 2020;182(2):398–404.
  5. Agazzi A, Fadanelli G, Vittadello F, Zulian F, Martini G. Reliability of LoSCAT score for activity and tissue damage assessment in a large cohort of patients with juvenile localized scleroderma. Pediatr Rheumatol Online J. 2018;16(1):37.
  6. Knobler R, Geroldinger-Simić M, Kreuter A, et al. Consensus statement on the diagnosis and treatment of sclerosing diseases of the skin, Part 1: Localized scleroderma, systemic sclerosis and overlap syndromes. J Eur Acad Dermatol Venereol. 2024;38(7):1251–80.
  7. Zulian F, Culpo R, Sperotto F, et al. Consensus-based recommendations for the management of juvenile localised scleroderma. Ann Rheum Dis. 2019;78(8):1019–24.
Clinical decision support only. This tool is intended to assist clinical assessment and does not replace professional judgment. Always interpret results in the context of the individual patient.