METAL ALLERGY IN NORTH NORWEGIAN SCHOOLCHILDREN AND ITS RELATIONSHIP WITH EAR PIERCING AND ATOPY

In 424 schoolchildren (223 boys and 201 girls) aged 7-12 years undergo ing routine patch tests, 21.0% (89 children), 38.8% (78/201) of girls and 4.9% (11/223) of boys, had had their ears pierced. 18.6% (79 child ren, 55 girls and 24 boys) gave a history of cutaneous reactions to me tallic jewellery, and in 17.2% (73 children, 49 girls and 24 boys), se nsitivity to one or more metals was confirmed. Metal allergy was confi rmed by patch testing in only 34.2% of the children with a history of metal dermatitis, and 13.3% of those without a history of metal reacti ons had, in fact, positive patch tests to 1 or more metals. The low se nsitivity (37.0%) and low positive predictive value (34.2%), together with high specificity (85.2%) and high negative predictive value (86.7 %), seem to justify dermatological examination of individuals with a p ositive symptom-based diagnosis only. Nickel sensitivity was found in 14.9% (63 children, 44 girls and 19 boys). There is clearly a relation ship between ear piercing and induction of nickel allergy in girls, as nickel sensitivity in girls with pierced ears was 2 x (30.8%) that fo und in those without (16.3%) pierced ears. In boys, nickel sensitivity was much less frequent and few cases were related to ear piercing, At opy appeared to influence the propensity for developing metal sensitiv ity in girls, as atopic girls showed positive metal tests 2 x as frequ ently (30.8%) as non-atopic (17.0%). No such differences were found in boys. Girls with a combination of atopy and ear piercing showed the h ighest frequency of positive metal tests (45.5%). The frequency of met al allergy increased with increasing number of holes in the ear lobes. Symptoms of nickel allergy were reported in 30.2% (19/63) of mothers whose children had nickel allergy, compared to 16.3% (59/361) of mothe rs whose children had negative nickel tests. Only 4 children reported symptoms of nickel allergy in their father. The high frequency of nick el sensitivity in all children tested may indicate an influence of sou rces other than ear piercing.