Physician Global Assessment for Vitiligo (PGA)

Clinical Tools

DESCRIPTION:
The Physician Global Assessment for Vitiligo (PGA) is a clinician-reported tool used to rate the severity, disease activity, and improvement in patients with vitiligo. It is scored on a 5-point Likert scale with a baseline score that may range from 0 (clear or no involvement/depigmentation) to 4 (severe disease or very extensive depigmentation).1-3

DISEASE STATES: 
Vitiligo

VALIDATED USES: 
Screening, Treatment Monitoring

ADMINISTRATION METHOD:
Clinician-Reported Outcome

COMMONLY USED IN:
Clinical Trials, Treatment Monitoring

DETAILED DESCRIPTION:
The Physician Global Assessment for Vitiligo is an intuitive, easy-to-use measure that is often used in clinical trials. It is also known as the Investigator Global Assessment (IGA) and sometimes is referred to as the Physician Global Vitiligo Assessment (PhGVA). The 5-point PGA/PhGVA assessment involves a visual evaluation of the skin by a physician, clinician, or an appropriate HCP representative who then assigns a score based on the totality of a subject’s vitiligo lesions (e.g., level of depigmentation and body surface area [BSA] covered).1-3 Similar to a Vitiligo Area Scoring Index (VASI), a clinician often will conduct separate assessments for the body (T-PhGVA) and face (F-PhGVA).3-5

PGA RATING SCALE FOR VITILIGO3,4

Average Scoring Assessment Vitiligo Description*
0 Clear
  • No signs of vitiligo or complete/near complete repigmentation
1 Almost clear
  • Mostly pigmented areas with small depigmented or difficult-to-repigment areas
2 Mild
  • Modest areas of depigmentation with approximately 50% pigmentation within vitiligo areas or significant perifollicular pattern present
3 Moderate
  • Large areas of depigmented vitiligo areas
  • Significant depigmentation within vitiligo areas
4 Severe
  • Extensive areas of vitiligo to complete depigmentation

*Based on PhGVA description, including facial vitiligo (F-PhGVA), in Bibeau et al. Dermatol Ther (Heidelb). 2024.

VALIDITY:
The PGA for Vitiligo scale has been validated across several studies.1-5 It has demonstrated good interrater reliability (ICC ~0.69).2 One study demonstrated correlations between both T-PhGVA and F-PhGVA and T-VASI and F-VASI (r = 0.63 and r = 0.65 respectively; P<0.001).5† The PGA also demonstrated construct validity for capturing meaningful change.3,4

LIMITATIONS:
Findings may lack generalizability due to small, homogenous study populations; one study population lacked diversity, overrepresenting skin types II-III, participants had limited BSA involvement, and cross-cultural validity could not be confirmed.1,3,5

ICC, Intraclass Correlation Coefficient. †Based on Spearman correlation; T-VASI correlated moderately with PhGVA-T (r = 0.63 at baseline and 0.65 at Week 24); F-VASI correlated moderately to strongly with PhGVA-F (r = 0.65 at baseline, 0.71 at Week 24).

This resource is intended for educational purposes only and is intended for US healthcare professionals. Healthcare professionals should use independent medical judgment. All decisions regarding patient care must be handled by a healthcare professional and be made based on the unique needs of each patient.

References: 1. Bibeau K et al. Dermatol Ther (Heidelb). 2024;14(8):2223-2234. 2. van Geel N et al. Pigment Cell Melanoma Res. 2019;32(5):728-733. 3. van Geel N et al. J Clin Med. 2024;13(9):2680.
4. Bibeau K et al. Dermatol Ther (Heidelb). 2024;14(8)(suppl.). 5. Ezzedine K et al. JAMA Dermatol. 2025;161(1):39-46.

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