Most common metal causing contact dermatitis

Nickel allergy is one of the most common causes of contact allergic dermatitis. The most common sites for nickel dermatitis are the earlobes (from earrings), the wrists (from a watch strap) and the lower abdomen (from a jeans stud); the affected areas become intensely itchy and may become red and blistered (acute dermatitis) or dry, thickened and pigmented (chronic dermatitis). Ref Harrison 20th edition pg 1234