Subjects with Nickel sensitization proved by patch test may suffer of contact 
eczema, but also of a Sistemic Nickel Allergy Syndrome (SNAS) consisting of 
urticaria-like troubles, itch, erythema, cutaneous rush, headache, intestinal 
symptoms, recurrent vesicular palmar dermatitis. 160 subjects (130 F, 30 M) were 
classified into three groups and underwent dosage of Nickel in urines (U-Ni) and 
blood (B-Ni). The two groups with SNAS showed an higher indicators of Nickel 
absorption, while the only-eczema group did not. 95 subjects with SNAS were 
enrolled for a Nickel-scanty diet: most of them improved. 24 ones again 
symptomatic were admitted to an experimental treatment, by a schedule of oral 
increasing microdose (nanograms) of Nickel sulphate: all of them improved. In 
conclusion Nickel pathology is changing, allergy seems to be due to different 
mechanism, dietary intake is important, an immune-tolerance can be induced.