A system for fluorescence-based imaging of a target includes at least one excitation light source configured to emit a homogeneous field of excitation light and positioned to uniformly illuminate a target surface with the homogeneous field of excitation light during fluorescent imaging, a power source, and a portable housing configured to be held in a user's hand during imaging. The housing contains a lens, a filter, an image sensor, and a processor. The filter is configured to permit optical signals responsive to illumination of the target surface and having a wavelength corresponding to at least one of bacterial autofluorescence and tissue autofluorescence to pass through the filter to the image sensor. The at least one excitation light is adjacent to the housing so as to be positioned between the target surface and the image sensor during fluorescent imaging.