Robyn Green's ear swelled up so badly the stud became almost embedded in her skin.
The 14-year-old now says she has contracted impetigo – a highly contagious skin infection – after the piercing went wrong.
The Highfield High pupil is off school recovering – but has vowed to warn her classmates of the dangers of going under the needle when she returns.
Robyn, of Horncliffe Road, South Shore, said: "I went out with my mates and got the top of my ear done in one place and my nose in another.
"My mum didn't know I was going to do it and no one asked me how old I was.
"I was actually 13 at the time because it was just before my birthday.
"Things were alright at first but then my ear got more and more painful.
"It swelled up around the hole and I had blisters all over my ear. It was awful.
"I don't regret having piercings, but I regret not planning it properly or telling my mum."
Robyn was put on antibiotics by doctors and has had the earring changed by another piercer because the original one was too short, which is why she was in pain when the ear swelled.
There is no requirement in law for piercers to get parental permission for children.
But Blackpool Council, which regulates businesses, advises shops to get permission for under 16s.
Robyn's mum Amanda wants the law tightened.
She said: "The rules really should be stricter.
"I made her take the nose stud out but thought the ear one was OK, but after a few days it started to get worse. It all blistered and it was weeping. I have reported the place she went to to Environmental Health."
A spokesman for Blackpool Council confirmed a complaint had been received and that it would be investigated.
James Woods, who runs the Body Piercing Clinic on Talbot Road, saw Robyn's ear after it swelled up.
He said: "I did not do the original piercing but she came to see me with her mum when she started to have problems.
"I would never pierce under 16s without their parents' permission. Just a few weeks ago I had a 12-year-old girl brought in by her mum to get a piercing taken out of her tongue.
"Her mum found her crying with her tongue swollen and bleeding heavily from her mouth and rushed her to me. She could have choked on the blood if her mum hadn't found her."
Collegiate High School pupil Stacey Bradley, 13, was banned from school after having her nose pierced in July 2004.
rebecca.smith2@blackpoolgazette.co.uk