Huuuy, grabe yan, 6 months na talaga at di pa tumitigil, na-frustrate ka siguro! Kaya yan mukhang may underlying thing, either infection na hindi agad lumalabas or maybe wet diaper area lang lagi kaya di tumitigil ang moisture, pero since sinundan mo na ng pedia at mupirocin, baka kailangan mo mag-follow up ulit or second opinion para sure, minsan kelangan mas malakas ang antibiotic or may ibang cause na dapat ma-check. In the meantime, make sure talaga na dry agad after the saline wash, maybe use a clean cloth na lightweight lang and let it air dry when you can para hindi laging moist ang area. Definitely worth bringing it up again sa doctor kasi unusual talaga na after 6 months + treatment, parang sugat pa rin!