You might try using antibiotic cream or ointment like Bacitracin in your bike shorts. It works just like Chamois Buttr but prevents infection. It washes out well too. Cortizone cream is Okay as a short term antiinflamatory, but if you use it for a prolonged period, it weakens and breaks down the skin. A general rule of thumb for any skin condition is "if it's wet, dry it; if it's dry, wet it". This is from my old RN days (prior career, but you never forget that stuff). You just might want to use some antibiotic cream all the time until the condition goes away. There's also the old "sitz bath" thing: sitting in a tub of warm water a couple of times a day.