Ten days after the euro was introduced, up to 20 Spaniards have sought treatment in a Barcelona hospital for painful itching and red hands caused by handling €1 and €2 coins.
Alvaro Cadahia, the head of allergies at Barcelona's Valle de Hebron hospital, said: "People have reacted to the nickel in some euro coins, and suffer dermatitis, itching, and reddening of the hands."
Nickel is known to cause numerous skin allergies, Dr Cadahia said. He said that women were more allergic to the element than men, with one in three women susceptible to the reaction.
The Spanish Allergy Society warned last month that supermarket cashiers and bank employees risked a reaction from the prolonged handling of euros. There is no easy solution, Dr Cadahia said."As months go by the symptoms will worsen with continuous contact. What starts as a skin complaint may produce cracks in the skin where fungi can lodge."
The use of nickel in coins has been contested in Europe since 1997, and Nordic countries refuse to use it. British and Swedish scientists say that those who are susceptible can suffer a reaction after holding a coin containing nickel for just five minutes.
€1 and €2 coins contain nickel that has been mixed with copper and tin. Those of 10, 20 and 50 euro cents contain so-called Nordic gold and those of one and two cents are made of copper-covered steel.
The coins have been produced by mints in the participating countries.
A spokesman for the European Central Bank said: "The nickel content of the euro coins is below the average of the nickel in almost all of the national series of coinage, including that of Spain and the UK. Given the excitement and enthusiasm over the euro, there may have been more exposure because of people looking at the coins more than they would with normal coins."Reuse content