A 9-year-old boy got the temporary tattoos he wanted while on vacation in Turkey, but when the black dye faded, he was left with permanent scarring and severe allergies, London’s Daily Mail reported.

Thomas Collins convinced his mother, Katie, to pay the 13 dollars for two black henna tattoos – one on each shoulder.

“It seemed like fun, and the tattoos only cost five Euros each,” said Katie, who lives in Lancashire, England. “Plus, the man doing the tattoos was based in the hotel complex, so I assumed it would be safe.”

When their family returned home, the black dye had faded, but Thomas’ arms began to itch and hurt. He also developed a high temperature.

“When I looked at his arms, I saw the outlines of the tattoos had been replaced by angry red blisters,” Katie said. “It looked awful – the blisters were raised and even looked a greeny-yellow color in some places. His arm was weeping and fluid was seeping out where the tattoos had been.”

Thomas suffered a severe allergic reaction to the paraphenylenediamine, a chemical sometimes added to henna to make it black, in his Bart Simpson and skull tattoos.

Henna tattoos are usually harmless when they have their natural brown or reddish color, but when the black dye is added they have been known to cause severe allergic reactions and even require plastic surgery.

Although Thomas’ reaction went away after two months, it triggered new allergies to certain medications and everyday products, such as printer ink, rubber, lawnmowers and sun lotion, which Katie said has been upsetting for Thomas.

“I’m just glad Thomas didn’t have the tattoos all over his body,” Katie said. “The doctor said that he had one of the worst reactions he had ever seen.”

Click here to read more from the Daily Mail.