Charlotte Gilmour, 23, spent a month in Palmerston North Hospital being treated for Stevens-Johnson syndrome, which affects fewer than one in a million people worldwide.
She had been dealing with a respiratory infection for a month when she woke up one morning with a strange rash and what she thought was conjunctivitis.
“I looked in the mirror and burst into tears. I think subconsciously I knew it was something very serious.”
Her doctor immediately diagnosed her with Stevens-Johnson syndrome – an extremely rare allergic reaction to medications.
The culprit in this case was lamotrigine, which Charlotte was taking to treat depression.
Once at Palmerston North Hospital, some Filipino nurses recognized Stevens-Johnson syndrome from cases in their home country, but no one had much information on how to treat it because it was so rare.
“It was scary, I think, to hear… 'Okay, no one really knows much about this.'”
Charlotte's skin developed huge blisters, as if she had been boiled. She needed a feeding tube because her mouth and esophagus were burned.
'The scariest thing about it is that it burned me from the inside out.
“So all the burns on the outside were because my insides were so burned that it started to manifest on the outside of my skin.”
Steroids initially made no difference.
'So they stopped them, [saying] “There's no point” and then it just got worse and worse, until one night it got so bad that I virtually lost my sight.
“I said, 'Can you please try some steroids again?', and that definitely helped in the end.”
After 30 days in hospital, she was discharged in November and, despite some setbacks, she has recovered well.
“I still get blisters in my eyes and the rash flares up, always in the same spot where the worst burn was.”
In the five years to the end of December, Medsafe received 710 reports of side effects from lamotrigine, including six deaths.
The government's medicines safety agency said around one in a thousand adults treated with lamotrigine would develop a serious skin rash which could – in very rare cases – progress to Stevens-Johnson syndrome.
These risks were greater in children taking lamotrigine for epilepsy.
Derek Fitzgerald, Medsafe's acting group manager, said adverse event reports were “broadly proportionate” to levels of use in New Zealand.
Last year, more than 17,000 people were prescribed the drug for various conditions.
“Effective medicines, which allow people with life-threatening conditions to live normal lives, can also often cause serious side effects in some people,” he said.
“Rare, but potentially life-threatening skin reactions such as Stevens-Johnson syndrome, linked to lamotrigine, are related to the drug itself and not the brand.
“Anyone who starts treatment with lamotrigine, or increases the dose of the medicine, and develops a rash should consult their doctor immediately.”
More than 200 drugs are known to cause Stevens-Johnson syndrome.