What is the most widely used system for grading acne scarring, how are the grades defined, and what are the recommended treatments for each grade?

Acne Scar Grading and Treatment

The Investigator Global Assessment (IGA) is the most widely used system in the United States for grading active acne, while the Goodman and Baron qualitative grading system (Grades 1-4) is the most established classification for acne scarring, with treatment escalating from topical therapies for Grade 1 to combined surgical and resurfacing approaches for Grade 4 scars. 1, 2, 3

Acne Scar Classification Systems

Goodman and Baron Grading System (Most Widely Used for Scarring)

The Goodman and Baron system provides both qualitative and quantitative assessment of post-acne scarring 2, 4, 5:

• Grade 1: Flat red, white, or brown marks (macular disease) visible primarily to the patient 2
• Grade 2: Mild scarring that is easily covered by makeup or facial hair, primarily visible in the mirror 2, 4
• Grade 3: Moderate scarring visible at conversational distance (50 cm) but distensible when skin is stretched 2, 4
• Grade 4: Severe scarring visible at distances greater than 50 cm, not distensible, and often associated with significant disfigurement 2, 4

Morphological Scar Types

The descriptive classification identifies three primary atrophic scar subtypes 3:

• Ice pick scars: Deep, narrow (< 2mm), sharply marginated scars extending into the deep dermis or subcutaneous tissue 3
• Rolling scars: Broad depressions with sloping edges caused by dermal tethering 3
• Boxcar scars: Round to oval depressions with sharply defined vertical edges, wider than ice pick scars (0.1-0.5mm) 3

IGA Scale for Active Acne (Not Scarring)

While the IGA is most commonly used in the US for active acne assessment, it measures disease severity rather than scarring 1. The consensus 5-point ordinal scale ranges from 0-4: clear, almost clear, mild, moderate, and severe 1.

Treatment Recommendations by Grade

Grade 1 Scars (Macular Changes)

Topical therapies and laser treatments are first-line for flat pigmentary changes 2:

• Topical retinoids, vitamin C, and hydroquinone for pigmentation 2
• Fractionated lasers (non-ablative) 2
• Pigment-specific or vascular-specific lasers depending on color 2
• Pigment transfer techniques for refractory cases 2

Grade 2 Scars (Mild Atrophic Scarring)

Non-ablative fractionated lasers and microneedling are the primary modalities 2, 5:

• Non-ablative fractionated lasers as first-line 2
• Microneedling (dermaroller) with 1.5-2.5mm depth, 4 sessions at 3-week intervals 5
• Skin rolling techniques 2
• All Grade 2 scars in one study improved to Grade 1 or complete resolution with microneedling 5

Grade 3 Scars (Moderate, Distensible)

Combination therapy with subcision plus resurfacing produces superior outcomes 2, 6:

• Subcision to release dermal tethering 6, 3
• Combined with microneedling (alternating sessions) 6
• 15% TCA peels alternated with microneedling every 2 weeks for 6 sessions each 6
• Fractional ablative or non-ablative lasers 2
• In one study, 68.2% of Grade 3 scars improved to Grade 2, with 22.7% achieving complete resolution 6

Grade 4 Scars (Severe, Non-Distensible)

Surgical intervention followed by resurfacing is essential for severe scarring 2, 3:

• Punch excision for deep ice pick scars 3
• Punch elevation for boxcar scars 3
• Subcision for rolling scars and dermal tethering 3
• Followed by laser resurfacing (ablative or fractional) 2
• Combination therapy: subcision + microneedling + TCA peels showed 62.5% of Grade 4 scars improving to Grade 2 6

Advanced Treatment Protocols

Microneedling with PRP/PRF

The American Academy of Dermatology recommends combining microneedling with platelet-rich plasma (PRP) or platelet-rich fibrin (PRF), with PRP/PRF applied before microneedling to allow deeper penetration 7, 8:

• Protocol: 3-4 sessions spaced 4 weeks apart 8
• Needle depth: 1.5mm for most acne scars 7, 8
• PRP preparation: Double-spin technique (1500 rpm for 10 minutes, then 3700 rpm for 10 minutes) 8
• Application timing: Apply PRP/PRF before microneedling, not after 8
• Outcomes: 70.43% mean improvement with 43% achieving excellent response 8
• PRF superiority: PRF shows 3-fold higher therapeutic response than PRP when combined with microneedling, but must be used within 20-40 minutes due to clotting 1, 8

Scar Type-Specific Response

Rolling scars respond best to treatment, followed by boxcar scars, while ice pick scars are most resistant 7:

• Rolling scars: Best response to subcision and combination therapies 7, 3
• Boxcar scars: Good response to punch elevation and resurfacing 3
• Ice pick scars: Often require punch excision before resurfacing 3

Technical Execution Pearls

Pre-Treatment Preparation

• Apply compounded topical anesthesia for minimum 30 minutes, then completely remove before starting 7, 8
• Map deeper scars for stamping technique at greater depth 7
• Ensure adequate skin lubrication to avoid dry tugging 7, 8

Post-Treatment Care

The American Society for Dermatologic Surgery recommends 7, 8:

• Avoid sunlight exposure for 24 hours post-procedure 7, 8
• Avoid heavily scented facial products for 24 hours 7, 8
• Use gentle, non-drying cleansers and non-comedogenic products 7, 8
• Consider maintenance treatments every 6 months after initial series 8

Safety Profile

PDRN and PRP-enhanced microneedling are safe for all skin types with minimal side effects 7, 8:

• Common transient effects: mild erythema, edema, bruising 8
• No immune reactions with PDRN due to absence of active proteins/peptides 7
• Significantly shorter downtime compared to ablative lasers 8

Contraindications

• Active infection at treatment site 7, 9
• Known hypersensitivity to treatment components 7
• Avoid treating over tattoos or permanent makeup 7, 9

Critical Clinical Considerations

Combination therapy consistently outperforms monotherapy across all scar grades 7, 8, 6. The synergistic mechanism involves creating controlled micro-injuries that trigger wound healing cascades while delivering growth factors directly into microchannels to amplify collagen remodeling 8.

Patient selection matters: Younger patients and those with more recent scars show better treatment responses 7. However, even severe Grade 4 scarring can achieve significant improvement with aggressive combination approaches 6.

Common pitfall: Applying PRP/PRF after microneedling rather than before significantly reduces efficacy, as the growth factors cannot penetrate adequately through intact skin 8.