Yes, systemic nickel is probably important!
Möller
H
H
D017449:Dermatitis, Allergic Contact / Q000209:etiology; D004032:Diet; D011146:Eczema, Dyshidrotic / Q000209:etiology*; D006229:Hand Dermatoses / Q000209:etiology; D006801:Humans; D009532:Nickel / Q000008:administration & dosage / Q000009:adverse effects*
D009532:Nickel