SKIN experts have released a warning about the dangers of 'black henna' tattoos after seeing a rise in the number of 'very nasty' reactions.

The British Skin Foundation claim they saw a rise in the number of patients with reactions to black henna tattoos in 2015 and are warning funfair and festival-goers to be wary ahead of the summer season.

According to the BSF the majority of black henna tattoos are not henna based and contain a substance called para-phenylenediamine (PPD).

The substance is allowed for use in hair dye but is banned for skin contact products, such as henna tattoos, by the European Union.

When PPD is used on the skin in this way it can cause blistering, painful skin burns and may even lead to scarring.

It can also leave the person with a lifelong sensitivity to PPD, which increases the risk of a severe allergic reaction when using hair dye in the future.

Dr Anjali Mahto, consultant dermatologist and BSF spokesperson said: “Black henna is well known to cause skin reactions and should be treated with caution, particularly in children.”

The decision to issue this warning is backed by the Cosmetic, Toiletry & Perfumery Association (CTPA).

Dr Christopher Flower, Director-General of the CTPA added: “The message is clear: having a ‘black henna’ temporary tattoo presents a significant risk of a very nasty adverse reaction to the tattoo itself.

"It also increases the risk of either not being able to use most hair dyes in the future or having a bad reaction to them if the warnings are ignored.

"Most importantly, parents will want to safeguard their children this summer by steering clear of so-called ‘black henna’ temporary tattoos.”