Pull up That Does Not Irritate Skin

Try cloth training pants with covers over them, so much better for his sensitive skin. I used them with my guy and had no problems.

He wasnt allergic to diapers but IS allergic to pull-ups?
Not sure what to tell ya. He may have started an allergy to "plastics"?
Try some cloth training pants with rubber pants over the top... do they still make those? They must since a lot of moms use cloth diapers.

We never had an issue...are they too big or too small? Is it the pullup itself or when he soils it?

Just like with diapers change when wet or poops don't let him stay in a dirty pull up that can cause an irriated reaction the weather is hot sweating in the creases can also cause irriation.Buy a size bigger than what he is in,put under wears on as often as possible ya pull ups are nice but under wears are to they get the same concept they get wet or pooped in still icky but they are washable maybe they are getting too small.You don't mention why he is irriated so i'm just assuming and giving advice off that.When washing undies since he is sensitive use a hypoallergenic fragrance free detergent and no fabric softner.

Check out www.onestepahead.com
I've seen some in their catalog that look easy to deal with. (Not disposable, they are cloth)

You might consider cloth training pants. If you've tried every brand, the he's going to be sensitive to everything. Cloth might be your only option.

I prefer cheap diapers over pull-ups. Have you tried any store brand diapers?

My daughter had a problem with the name brand pullups. Target pullups worked for her.

You may want to research cloth training pants. As for my sensitive DS, Target brand pull ups were the least irritating.

If you are potty training, cloth trainers will work better for you in the long run.

If you are using them otherwise, have you tried the Seventh Generation ones?
I'm personally a big fan of using diapers until they are ready for underpants.