Montreal ? A Canadian coroner confirmed Thursday that a teenager – once believed to have died from a peanut allergy after kissing her boyfriend – died from an asthma attack.

Coroner Michael Miron said Christina Desforges, 15, died from cerebral anoxia, or lack of oxygen to the brain, triggered by a severe asthma attack.

In a preliminary report in March, Miron rejected a peanut allergy as the cause of death, saying he suspected cerebral anoxia. But he provided no further details.

The 15-year-old girl stopped breathing on Nov. 20 after kissing her boyfriend, who had eaten a peanut butter snack. Official findings at the time linked the death to a peanut allergy, drawing widespread media attention.

But Miron said the initial report that lingering peanut allergens from that kiss triggered an allergic reaction was wrong.

He said she had spent hours at a party with smokers when her breathing problems began. About 3 a.m., Desforges said she was having trouble breathing and collapsed shortly after.

She was taken to the hospital, but the coroner estimates her brain was deprived of oxygen for 25 to 30 minutes. She was taken off life support nine days later.