What is the ranking of topical steroid potency?

Topical Corticosteroid Potency Classification

Topical corticosteroids are classified into 7 classes based on vasoconstrictor potency, with Class 1 being ultra-high potency (strongest) and Classes 6-7 being low potency (weakest). 1

Classification System

The American Academy of Dermatology uses a 7-tier classification system based on skin vasoconstrictive activity: 1

Class 1 (Ultra-High/Super-High Potency)

• Clobetasol propionate 0.05% 1, 2
• Halobetasol propionate 0.05% 1
• Efficacy: 58-92% 1
• Maximum duration: 2-4 weeks continuous use 3, 1
• Maximum weekly dose: ≤50 grams 3

Class 2 (High Potency)

• Betamethasone dipropionate 0.05% 1
• Amcinonide 0.1% 1
• Fluocinonide 0.05% 1
• Efficacy: 68-74% 1

Classes 3-4 (Medium Potency)

• Fluticasone propionate 0.005% 3
• Betamethasone valerate 3
• Efficacy: 68-72% 1
• Duration: Up to 4 weeks for plaque psoriasis 1

Class 5 (Lower-Medium Potency)

• Hydrocortisone 17-butyrate 21-propionate 3
• Efficacy: 41% achieved excellent/good improvement 3

Class 6 (Low Potency)

• Fluocinolone acetonide 0.01% 3
• Desonide 1
• Efficacy: 41-83% 1
• No specified time limit for use 1, 4

Class 7 (Lowest Potency)

• Hydrocortisone 1% and 2.5% 1

Site-Specific Selection Algorithm

Face, Genitals, and Intertriginous Areas

• Use only Classes 5-7 (low potency) due to increased absorption and atrophy risk 3, 1
• Class 6 corticosteroids are specifically recommended for facial dermatoses and intertriginous areas 1

Thick, Chronic Plaques (Body/Extremities)

• Start with Class 1 (ultra-high potency) for severe disease 1
• Potent and very potent topical corticosteroids demonstrate superior efficacy compared to mild or moderate agents 3

Scalp

• All classes can be used for up to 4 weeks 1
• Betamethasone valerate foam (Class 4) showed 72% improvement versus 47% placebo 3

Pediatric Patients

• Prefer Class 6 corticosteroids due to lower systemic absorption risk and minimal HPA axis suppression 1

Efficacy Comparison

Higher potency agents demonstrate significantly greater efficacy than lower potency agents: 3

• Potent vs. mild potency: 70% versus 39% treatment success (OR 3.71) 5
• Moderate vs. mild potency: 52% versus 34% treatment success (OR 2.07) 5
• Potent vs. moderate potency: No significant difference (OR 1.33, CI 0.93-1.89) 5
• Very potent vs. potent: Uncertain evidence (OR 0.53, CI 0.13-2.09) 5

Critical Safety Considerations

Skin Atrophy Risk by Potency

From 2,266 participants across 22 trials, abnormal skin thinning occurred in only 1% overall, but distribution by potency was: 5

• 16 cases with very potent (Class 1)
• 6 cases with potent (Classes 2-3)
• 2 cases with moderate (Class 4)
• 2 cases with mild (Classes 5-7)

Common Pitfalls to Avoid

• Never use Class 1 steroids on face or intertriginous areas - all steroid users developed atrophy with clobetasol after only 8 weeks 3
• Do not exceed 50 grams weekly for Class 1 steroids 3
• Avoid continuous use beyond 2-4 weeks for Class 1 3, 1
• Class 1 steroids used for 4 months caused hypertrichosis and acne 3

Application Frequency

Once daily application is equally effective as twice daily for potent topical corticosteroids (OR 0.97, CI 0.68-1.38), allowing for simplified regimens without loss of efficacy 5