Ozzy Osbourne fears he'll have to scale down his annual summer Ozzfest shows - because they're playing havoc with his allergies.

The former Black Sabbath rocker admits he struggles with open-air shows every year and wants to play fewer dates and make up for lost gigs by playing arena concerts.

He says, "It would be kinda cool to do a few shows in a few arenas as well because I haven't done an arena for years.

"(With the open-air shows), you're out in the elements and my allergies go wild. I'm allergic to everything. I've been bitten by every poisonous thing on the planet."