What is the classification and usage of topical steroids based on potency?

Topical Corticosteroid Potency Classification

Topical corticosteroids are classified into 7 classes based on their vasoconstrictor potency, ranging from Class 1 (ultra-high/superpotent) to Class 7 (lowest potency), with selection based on disease severity, anatomical location, patient age, and treatment duration. 1

Classification System

Class 1: Ultra-High Potency (Superpotent)

• Clobetasol propionate 0.05% (cream, ointment, gel, foam, solution, shampoo) 1
• Halobetasol propionate 0.05% (cream, ointment) 1
• Betamethasone dipropionate 0.05% (optimized ointment) 1
• Diflorasone diacetate 0.05% (ointment) 1

Class 2: High Potency

• Amcinonide 0.1% (cream, ointment) 1
• Betamethasone dipropionate 0.05% (cream, ointment) 1
• Desoximetasone 0.25% (cream, ointment) 1
• Fluocinonide 0.05% (cream, gel, ointment, solution) 1
• Halcinonide 0.1% (cream, ointment) 1

Class 3: Upper Mid-Strength Potency

• Betamethasone valerate 0.1% (ointment) 1
• Desoximetasone 0.05% (cream) 1
• Fluticasone propionate 0.005% (ointment) 1
• Triamcinolone acetonide 0.5% (cream, ointment) 1

Class 4: Mid-Strength Potency

• Mometasone furoate 0.1% (cream, ointment) 1
• Triamcinolone acetonide 0.1% (ointment) 1
• Fluocinolone acetonide 0.025% (ointment) 1

Class 5: Lower Mid-Strength Potency

• Betamethasone valerate 0.1% (cream, lotion) 1
• Fluticasone propionate 0.05% (cream) 1
• Hydrocortisone butyrate 0.1% (cream, ointment) 1
• Hydrocortisone valerate 0.2% (cream, ointment) 1
• Prednicarbate 0.1% (cream) 1

Class 6: Mild Potency

• Alclometasone dipropionate 0.05% (cream, ointment) 1
• Desonide 0.05% (cream, ointment, lotion) 1

Class 7: Lowest Potency

• Hydrocortisone 1.0%, 2.5% (cream, ointment, lotion) 1
• Dexamethasone 0.1% (cream) 1

Clinical Application Guidelines

Anatomical Site Selection

Lower potency corticosteroids (Class 6-7) must be used on the face, intertriginous areas (groin, axillae), and areas susceptible to atrophy such as forearms. 1, 2

Moderate to high potency corticosteroids (Class 2-5) are recommended for trunk and extremities in adults with inflammatory conditions. 1, 2

Class 1 ultra-high potency corticosteroids are reserved for thick, chronic plaques on non-sensitive areas and should not exceed 2-4 weeks of continuous use. 1

Duration of Treatment by Potency Class

• Class 1 (Ultra-high potency): Maximum 2-4 weeks continuous use 1
• Class 2-5 (High to moderate potency): Up to 12 weeks 3
• Class 6-7 (Low potency): No specified time limit 3

Efficacy Rates by Class

Class 1 corticosteroids demonstrate 58-92% efficacy rates in treating moderate to severe psoriasis within 2-4 weeks. 1

Class 2 corticosteroids show 68-74% efficacy rates. 1

Class 3-4 corticosteroids demonstrate 68-72% efficacy rates. 1

Class 5-7 corticosteroids show 41-83% efficacy rates, with wider variability. 1

Disease-Specific Recommendations

Psoriasis

For localized plaque psoriasis, Class 2-5 corticosteroids are recommended as initial therapy for up to 4 weeks. 1, 2

Very potent topical steroids (clobetasol propionate) applied to lesional skin alone carry strength of recommendation A for localized disease. 1

Vitiligo

Potent or very potent topical steroids (clobetasol, betamethasone, fluticasone) should be considered for recent-onset vitiligo for a trial period of no more than 2 months due to high risk of skin atrophy. 1

Clobetasol (Class 1) caused skin atrophy in all users after 8 weeks, while betamethasone caused hypertrichosis and acne after 4 months. 1

Atopic Dermatitis

Moderate potency topical corticosteroids are indicated for moderate atopic dermatitis cases. 2

Critical Safety Considerations

Common Pitfalls to Avoid

Never use high-potency corticosteroids on facial skin, genitals, or intertriginous areas due to increased risk of atrophy, striae, telangiectasias, and systemic absorption. 3

Avoid occlusion with high-potency steroids as this dramatically increases systemic absorption and adverse effects. 3

Do not exceed 2-4 weeks of continuous Class 1 corticosteroid use to prevent both cutaneous side effects and systemic absorption. 1

Adverse Effects by Risk Level

Risk of adverse effects increases with: prolonged use, large application area, higher potency, occlusion, and application to thin-skinned areas. 3

Local adverse effects include skin atrophy, striae, rosacea, telangiectasias, purpura, hypertrichosis, and acne. 4, 3

Systemic adverse effects from excessive use include hypothalamic-pituitary-adrenal suppression and Cushing's syndrome. 5

Steroid-induced hypopigmentation resolution is unpredictable and may take months to years. 4

Practical Application Method

Fingertip Unit Dosing

One fingertip unit (from fingertip to distal interphalangeal joint crease) covers approximately 2% body surface area in adults. 3

Approximately 400g of topical agent is required to cover the entire body surface of an average adult when used twice daily for 1 week. 1

Application Frequency

Topical corticosteroids are typically applied once or twice daily. 3

For maintenance therapy after initial control, intermittent use (2 times/week) of moderate potency corticosteroids reduces disease flares and relapse. 2

Reassessment Timeline

Reassess after 2-4 weeks to determine if continued treatment is necessary and to monitor for adverse effects. 2