Hypopigmented skin alterations resembling tuberous sclerosis in normal skin.

The significance of hypopigmented skin findings as manifestations of the gene for tuberous sclerosis (TS) in near relatives of TS patients is a difficult problem. We therefore studied the number and kind of whitish skin alterations found in 100 medical students and 100 school children. Ninety three percent of the former and 79% of the latter had some whitish lesions, many of them scars. Twenty percent of the adults and 12% of the children had roundish or oval macules larger than 10 mm in diameter, not known to be scars. In clinical practice with TS patients, our attention has been drawn to whitish raised masses or streaks in their first degree relatives. These were also found in study subjects so the significance of such lesions remains unclear. The role of Wood's light turned out to be questionable, far from pathognomonic for TS; 25% of all the whitish findings and 53% of the hypopigmented macules larger than 10 mm in diameter showed distinct or brilliant fluorescence under Wood's light.