Determination of Minimal Erythema Dose of Normal Skin to Ultraviolet Rays / 中华皮肤科杂志

ABSTRACT

Objective To determine the normal range of minimal erythema dose (MED) of normal skin to ultraviolet A (UVA) and B (UVB). Methods The definition of MED is the dose of UVA required to induce a just perceptible erythema on an individual′s skin 24 hours after irradiation. One hundred and eighteen subjects including healthy volunteers and patients with noninflammatory skin disorders were enrolled and studied with SUV1000 type UV simulator in March 2002. Results The average MED value for UVA was 55 J/cm2 (range: 18 - 95 J/cm2) in the males, and 40 J/cm2 (range: 15 - 100 J/cm2) in the females. The average MED value for UVB was 31 mJ/cm2 (range: 12 - 95 mJ/cm2) in the males and 29 mJ/cm2 (range: 8 - 95 mJ/cm2) in the females. The MED value for UVA in the males was significantly higher than that in the females (P 0.05). The MED values for UVA as well as UVB in skin type Ⅲ were significantly lower than those in skin type Ⅳ (UVA-MED: P