ULTRAVIOLET ERYTHEMA SENSITIVITY IN ANAMNESTIC (I-IV) AND PHOTOTESTED(1-4) CAUCASIAN SKIN PHOTOTYPES - THE NEED FOR A NEW CLASSIFICATION-SYSTEM

The anamnestic skin phototypes (ASP) I-IV1,2 of 21 Caucasian volunteer s were compared with their phototested skin phototypes (PSP) using sol ar simulating, broadband UV radiation. The Commission Internationale d e l'Eclairage (CIE)-weighted (i.e. erythemally effective) minimal eryt hema doses (MED) for solar simulating radiation varied from 20 mJ/cm(2 ) (PSP type 1) to 57 mJ/cm(2) (PSP type 4). In only 11 of 21 volunteer s did the ASP (I-IV) and PSP (1-4) classifications coincide, and the M ED values of the volunteers within the different ASP groups (I-IV) ove rlapped considerably. To compare the reactivity to erythematogenic rad iation of different wavelengths, narrowband monochromator irradiations were performed at 298 nm, 310 nm and 330 nm. The CIE-weighted MED val ues at these wavelengths (20-80 mJ/cm(2)) corresponded well with those obtained in the broadband testing. Our results indicate that, with cl assification by interrogation, Caucasian skin can reliably be classifi ed into only two subtypes, corresponding to Fitzpatrick phototypes I-I II and phototype IV, respectively. A classification into four sensitiv ity types can be achieved by phototesting, only. We propose that the c oncept of ASP should be used with caution. The concept of PSP 1-4 shou ld be favored.