Methods and apparatus are described for detecting acne, particularly in its earliest stages before any humanly visible or palpable manifestations thereof have emerged. An arrangement is described in which a green fluorescence image of an area of skin illuminated with blue light is captured and processed to detect the presence of microcomedones. The captured green fluorescence image is corrected for the non-uniform distribution of excitation light on the surface of the illuminated area of skin. Fluorescent spots are then detected in the corrected image. The subset of fluorescent spots having an intensity lower than an intensity threshold and an area smaller than an area threshold are selected as representative of candidate microcomedones. The subset can be further refined by eliminating fluorescent spots that have irregular shapes, are associated with inflammation, or exhibit comedone features. Additional filtering can be applied by selecting those spots whose locations correspond to those of pores. A dermatoscope with a blue illumination source and a green-filtered viewer allows live imaging of skin spots indicative of acne, including microcomedones not otherwise visible with the naked eye.
