food allergy due to sensitisation to nickel containing foods: hyposentisation is feasible and efficacious

FOOD ALLERGY DUE TO SENSITIZATION TO NICKEL CONTAINING FOODS: HYPOSENSITIZATION IS FEASIBLE AND EFFICACIOUS Luisa RICCIARDI,EleonoraARENA, Anna D’ANGELO, IsidoraPAFFUMI, FrancescaSINAGRA, GiuseppeLOSCHIAVO, SalvatoreSAITTA Allergy and Clinical Immunology Division. University of Messina, Messina, Italy Background The prevalence of nickel hyper-sensitivity varies widely in different countries and it is the leading cause of contact dermatitis in the general population. In some sensitized subjects, nickel is able to elicit cutaneous symptoms irrespective of the direct skin contact, causing systemic contact dermatitis. Although nickel is largely diffuse in objects and cosmetics, the major source of exposure for the general population is given by its presence in the diet (mainly food plant), which in some nickel-sensitive subjects can provoke/aggravate eczema and systemic contact dermatitis, but that has also been associated to the occurrence of extra-cutaneous symptoms (gastrointestinal, neurological), as well as to other systemic reactions (urticaria, angioedema, or other aspecific systemic clinical manifestations). The presence of these symptoms, correlated to the ingestion of foods and beverages containing high amount of nickel, in sensitized individuals, defines the so called "Systemic Nickel Allergy Syndrome"(SNAS). Method In the period between June 2006 and December 2012, 250 (240 f- 10 m; mean age, 31+ 26 + 13.04 years; range, 18-64 years) because of a clinical suspicion of SNAS, underwent a nickel patch-test according to the International Contact Dermatitis Research Group Guidelines. Therefore, after confirming cutaneous sensitization to nickel, a low nickel diet was prescribed with food which are generally tolerated by patients with SNAS while food which usually cause exacerbation of SNAS had to be avoided. The low nickel diet caused clinical improvement of symptoms correlated to SNAS in 221 patients, who underwent an oral nickel provocation test in our allergy outpatient Unit. The test was positive in 198 patients and negative in 13. Nickel Oral Hyposensitizing Treatment (NOHT) was started in 189 patients, following an up-dosing schedule from 0.1 ng to 500 ng. The maintenance treatment consisted in the administration of 500 ng capsules 3 times a week. Visual analogue score (VAS) was assessed at each visit. Results NOHT overall improved patient’s quality of life, reducing drug consumption, inducing recovery from symptoms and tolerance to nickel containing foods. Conclusions SNAS being an allergic disease due to nickel contained in foods and requiring the need for a special diet should be taken into account by health professionals and dieticians when evaluating food related problems in order to reach a correct diagnosis and treatment withNHOT. The above reported experience is in “real life” but similar inclusion criteria were used in a recent multicentre double-blind placebo controlled study which also showed the efficacy ofNickel Oral Hyposensitizing Treatment.