After acne, Cameron Diaz now battling psoriasis

After battling acne for years, Cameron Diaz has yet another skin condition to deal with.

The movie beauty has a nasty case of psoriasis just below her right elbow - and the itch is known as 'heartbreak' by skin doctors, because it doesn't clear easily and can come back.

Psoriasis is a pesky form of non-contagious inflammation.

Diaz dared to bare her arms as she unveiled her star on the Hollywood Walk of Fame on Monday and onlookers could clearly make out the mark on the actress' sleeve.

Celebrity skin expert Dr. Vail Reese has been scrutinising the actress' scabs and pimples for years and he insists the ringworm on her arm is just the latest in a long line of pigment problems for the actress.

"After battling acne for years, yet another skin condition to deal with! She has also suffered with facial pigmentation issues and sun overexposure," Contactmusic quoted Reese as saying.

"Though she is not my patient, it looks she has a form of psoriasis, that's showing some clearance in the center portion.

"Treatment for small areas involves prescription topical cortisone creams and vitamin D creams. Extensive psoriasis can be treated with injectable anti-inflammatory medicines called biologics. Since they suppress the immune system and can increase the risk of infections, those tend to be reserved for wider areas," he added.