diaper irritation...help!

livalil319

DS has been potty trained (day) for 3 months and we have used disposables at night trying to use up the last of a pack leftover from a trip.  I got him back in cloth last weekend for nights and his penis turned bright red overnight and he was crying on the potty saying it hurt.  At first I thought maybe it was irritation from running around with no underpants in his pajamas all day.  So we did powder and vaseline and a disposable again that night and all looked better the next day.  Back to cloth again the next night and now the very tip of his penis is bright red....I put neosporin on it for now.  I can't imagine what else could be causing it but the diapers.  Has anyone else ever had their child have a reaction to going back in cloth after a while out of it?  He always has had sensitive skin but he never had this problem. He was in a blueberry pocket with MF and AFFF.  Diaper didn't leak but was very wet and ammonia-y by morning. Could the ammonia cause the irritation? Would additional hemp help diffuse it?  I want to be able to use our CD's but not at the expense of poor DS' penis.  Suggestions?