Systemic nickel allergy syndrome: epidemiological data from four Italian allergy units

Area of Science:

• Allergology and Immunology
• Dermatology
• Epidemiology

Background:

• Nickel hypersensitivity is a leading cause of contact dermatitis globally.
• Dietary nickel can trigger eczema and systemic symptoms in sensitive individuals.
• Systemic Nickel Allergy Syndrome (SNAS) is defined by nickel-induced symptoms in patch-test positive patients.

Discussion:

• This study estimates SNAS prevalence at 5.78% in a Sicilian population, suggesting it's an emergent condition.
• Cutaneous and gastrointestinal symptoms were most frequently reported.
• A significant association between SNAS and IgE-mediated food allergy was observed.

Key Insights:

• SNAS prevalence estimated at 5.78% in the studied population.
• Dietary nickel intake can manifest as systemic symptoms beyond skin reactions.
• Co-occurrence of SNAS and IgE-mediated food allergy suggests shared underlying mechanisms.

Outlook:

• Further research on larger populations is needed to confirm these findings.
• Increased clinical suspicion for SNAS is warranted in patients with unexplained cutaneous and extra-cutaneous symptoms.
• Investigating cross-facilitating pathways between nickel allergy and food allergies may reveal new therapeutic targets.