Categorized based on their anti-inflammatory potency, which is determined by vasoconstrictor assay, receptor affinity, formulation, and absorption characteristics
U.S. (7-Class System) – From Super Potent to Least Potent
Class | Potency Level | Example Agents |
Class I | Super potent (Ultra high potency) | Clobetasol propionate 0.05%, Halobetasol propionate 0.05%, Betamethasone dipropionate 0.05% (augmented) |
Class II | High potency | Betamethasone dipropionate 0.05% (non-augmented), Fluocinonide 0.05%, Mometasone furoate 0.1% (ointment) |
Class III | Upper medium potency | Fluticasone propionate 0.005% (ointment), Triamcinolone acetonide 0.5% (ointment/cream) |
Class IV | Medium potency | Triamcinolone acetonide 0.1% (ointment), Mometasone furoate 0.1% (cream) |
Class V | Lower medium potency | Hydrocortisone valerate 0.2%, Betamethasone dipropionate 0.05% (lotion) |
Class VI | Mild potency | Desonide 0.05%, Alclometasone dipropionate 0.05% |
Class VII | Least potent | Hydrocortisone 1–2.5% |
U.K./European (4-Class System)
Group | Potency Level | Example Agents |
Group I | Mild | Hydrocortisone 0.5–2.5%, Prednisolone 0.5% |
Group II | Moderate | Clobetasone butyrate 0.05% |
Group III | Potent | Betamethasone valerate 0.1%, Mometasone furoate 0.1%, Fluocinonide 0.05% |
Group IV | Very potent | Clobetasol propionate 0.05%, Halobetasol propionate 0.05% |
Key Factors Affecting Potency
- Formulation/base: Ointments > creams > lotions/solutions
- Occlusion markedly increases absorption and potency
- Site of application (thin skin absorbs more):
eyelids < face < trunk < palms < soles (least absorption)
- Age (children absorb more than adults)
Clinical Implication
Potency | Appropriate Use | Avoid or Use with Caution |
Mild | Face, intertriginous areas, children | Deep-plaque psoriasis, lichenified lesions |
Moderate | Eczema, dermatitis on body | Prolonged facial or groin application |
Potent | Psoriasis, lichen simplex chronicus, severe eczema | Prolonged use in children/face/genital areas |
Very Potent | Refractory plaques, thick skin areas (soles/palms) | Children, long-term use, face, flexures, genitalia |
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