A set of multienzymes (peptide synthase CepA, CepB, and CepC) are responsible for assembling the heptapeptide. (Figure 2). The organization of CepA, CepB, and Cep C closely resembles other peptide synthases such as those for surfactin (SrfA1, SrfA2, and SrfA3) and gramicidin (GrsA and GrsB).  Each peptide synthase activates codes for various amino acids to activate each domain. CepA codes for modules 1, 2, and 3. CepB codes for modules 4, 5, and 6, and CepC codes for module 7. The three peptide synthases are located at the start of the region of the bacterial genome linked with antibiotic biosynthesis, and span 27 kb. 
Remember that we all think what we have is the same medical condition. It appears to be very common. Myself, I jump to conclusions often and am often wrong, but never in doubt. So I’ll stop using the heat pad and see if it clears up. One real threat is always things like that possibly becoming cancerous, so I’ll be happy with skin blotches as long as they don’t turn into skin cancer. Only a biopsy might really tell if it’s cancerous, so you roll the dice if you decide not to go to a skin cancer specialist. It seems a prolonged irritation of anything in your body might predispose the organs to cancer (smoking and sunburn are cases in point).