GAGS (Global Acne Grading System)

The Global Acne Grading System (GAGS; Doshi and colleagues 1997).

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

Forehead
3
Right cheek
3
Left cheek
2
Nose
1
Chin
2
Chest and upper back
1

Result: GAGS 22 of 44: moderate.

The tool opens with these values already filled in. Replace them with your own.

What the result means

Grade
The MOST SEVERE lesion in the region: 1 comedone, 2 papule, 3 pustule, 4 nodule. Never a sum of lesion types.
Regions
Forehead 2, each cheek 2, nose 1, chin 1, and chest with upper back 3 as ONE combined region.
0
None.
1 to 18
Mild.
19 to 30
Moderate.
31 to 38
Severe.
Above 39
Very severe. NOTE: the published table leaves exactly 39 in no band, and 39 is reachable.
Scope
Severity only. Does not diagnose acne, and misses scarring and psychological burden.

What you enter

  • Forehead.
  • Right cheek.
  • Left cheek.
  • Nose.
  • Chin.
  • Chest and upper back (ONE combined region, not two).
Full field descriptions
  • Forehead. Regional factor 2. Grade by the MOST SEVERE lesion present, not by summing lesion types [0 = No lesions; 1 = At least one comedone; 2 = At least one papule; 3 = At least one pustule; 4 = At least one nodule]
  • Right cheek. Regional factor 2. Grade by the MOST SEVERE lesion present, not by summing lesion types [0 = No lesions; 1 = At least one comedone; 2 = At least one papule; 3 = At least one pustule; 4 = At least one nodule]
  • Left cheek. Regional factor 2. Grade by the MOST SEVERE lesion present, not by summing lesion types [0 = No lesions; 1 = At least one comedone; 2 = At least one papule; 3 = At least one pustule; 4 = At least one nodule]
  • Nose. Regional factor 1. Grade by the MOST SEVERE lesion present, not by summing lesion types [0 = No lesions; 1 = At least one comedone; 2 = At least one papule; 3 = At least one pustule; 4 = At least one nodule]
  • Chin. Regional factor 1. Grade by the MOST SEVERE lesion present, not by summing lesion types [0 = No lesions; 1 = At least one comedone; 2 = At least one papule; 3 = At least one pustule; 4 = At least one nodule]
  • Chest and upper back (ONE combined region, not two). Regional factor 3. Grade by the MOST SEVERE lesion present, not by summing lesion types [0 = No lesions; 1 = At least one comedone; 2 = At least one papule; 3 = At least one pustule; 4 = At least one nodule]
How this is calculated
Method
Six regions, each factor times grade 0-4, summed. Factors total 11, so the score runs 0 to 44.

Doshi A, Zaheer A, Stiller MJ. A comparison of current acne grading systems and proposal of a novel system. Int J Dermatol. 1997;36(6):416-418. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

Browse all tools

Built by Clay Good. Source on GitHub.