I truly believe there is a metaphysical cause / manifested distortion that causes nearly all bodily issues.
However, in my own experiences, finding the undealt with catalyst that is now manifesting as a bodily distortion is similar to dreams. Some dream symbols are in the collective unconcious and fairly easy to decipher (water/ocean = subconcious), but other dream symbols are different to interpret. I've found that some bodily distortions usually translate easily based on the common/google-found chakra-body connections (most allegies, diabetes, etc), but others seem to be individualized symbols, not unlike individualized dream symbols. I think it's a good idea to start with the common links between skin and certain chakras (haven't done my own research regarding rashes so won't comment), but I think it's very useful to expand the possible symbolic feedback the bodily distortion is giving you. Your mileage may vary of course; this is definitely an area I'm still exploring.
Good luck my man.
However, in my own experiences, finding the undealt with catalyst that is now manifesting as a bodily distortion is similar to dreams. Some dream symbols are in the collective unconcious and fairly easy to decipher (water/ocean = subconcious), but other dream symbols are different to interpret. I've found that some bodily distortions usually translate easily based on the common/google-found chakra-body connections (most allegies, diabetes, etc), but others seem to be individualized symbols, not unlike individualized dream symbols. I think it's a good idea to start with the common links between skin and certain chakras (haven't done my own research regarding rashes so won't comment), but I think it's very useful to expand the possible symbolic feedback the bodily distortion is giving you. Your mileage may vary of course; this is definitely an area I'm still exploring.
Good luck my man.