Mike Waites Health Correspondent A WARNING is issued today that hair dyes could be leaving increasing numbers of people at risk of serious allergic reactions.

More than two-thirds of hair dyes currently contain the chemical compound para-phenylenediamine and other related substances, which can cause swelling and skin complaints.

The substance has been banned in Germany, France and Sweden.

In today’s British Medical Journal, John McFadden, of the St John’s Institute of Dermatology, and Ian White, a consultant dermatologist, warn of the dangers and call for a wider debate on the safety and composition of dyes.

They say increased use of dyes through the “culture of youth” and fashion put people at greater risk.