RELATIONSHIP BETWEEN MINIMAL PHOTOTOXIC DOSE AND SKIN COLOR PLUS SUN EXPOSURE HISTORY - A NEURAL-NETWORK APPROACH

Before beginning PUVA-therapy it is important to accurately gauge an i ndividual's degree of psoralen photosensitivity. This determination is usually based on an individual's skin phototype or minimal phototoxic dose. Since minimal phototoxic dose is technically complex and time c onsuming to measure, sun reactivity skin phototype is often used inste ad; however, it has recently been shown that skin phototype lacks spec ificity as a predictor of an individual's minimal phototoxic dose. In this study, an artificial neural network was developed to attempt to p redict the minimal phototoxic dose from skin colour measurements combi ned with skin phototype. Our results showed that minimal phototoxic do se was predicted with an error less than 1 J/cm(2) in only about half the subjects. In conclusion, minimal phototoxic dose probably cannot b e predicted with sufficient accuracy on the basis of skin colour and s kin phototype alone.