Table 1: MED values (mean±SD) (mJ/cm2) tested for study groups and calculated for epidermal structures.


Test group Skin phototype

II (n= 10) III (n= 10) IV (n= 10) V (n= 10) Total (n= 40)
Skin models VS 104.1±21.1 116.8±27.3 140.1±32.8 145.6±37.5 124.3±33.8
V 124.8±25.3 140.1±32.8 164.9±39.1 174.5±45.1 150.4±40.2
NS 137±29.3 151.3±39 173±50.6 183.6±60.2 160.1±48
N 154.4±26.8 170.1±36 195.1±50 211.2±60.5 180.1±48.8
Epidermal structures SC† 20.7±4.3 23.3±5.5 24.8±10.9 28.9±7.5 24±7.8
VE‡ 104.1±21.1 116.8±27.3 140.1±32.8 145.6±37.5 121.7±33.8
Melanin* 29.6±8.5 30±6.5 30.2±12.9 36.7±21 33.3±13.2

MED, minimal erythema dose; N, nonlesional; NS, nonlesional stripped; SC, stratum corneum; V, vitiliginous; VE, viable epidermis apart from melanin; VS, vitiliginous stripped. *MED value for each epidermal structure was calculated as illustrated: †V minus VS; ‡VS; *N minus V.