Washington – As Pamela Meredith sank onto her sofa to watch a movie with her visiting grandson, she felt relieved that their busy day was over. The day’s heat, combined with the pace required to keep up with an active 12-year-old, had sapped her energy, which had flagged in recent weeks.
As she put her feet up, Meredith was alarmed to see that her normally slim ankles were swollen, obscured by bands of puffy flesh. The retired nurse gingerly pressed her finger into one ankle. The pressure left a visible dent in her skin, a telltale indication of a condition called pitting oedema, caused by an accumulation of fluid in body tissues.
As Meredith mentally scrolled back through the events of August 1, 2013, for a possible cause, she suddenly worried that her worsening fatigue might portend something ominous. She had dismissed recent sporadic heart palpitations as a mere nuisance, the recurrence of a harmless condition that had first appeared in her thirties. But the combination of oedema, worsening fatigue and palpitations seemed to point in one direction: a heart attack.
A few hours later, tests at a hospital quickly ruled out Meredith’s biggest fear. She had not had a heart attack. But her level of potassium, critically important in regulating blood flow and kidney function, was perilously low and her normally low blood pressure was dangerously high.
Meredith was admitted to the intensive care unit, where doctors spent the next four days figuring out what had caused her problem – and how best to treat it.
The answer proved to be both simple and surprising, revealing a malady with which Meredith was unfamiliar.
“This is definitely an under-recognised problem,” said Dr Hesham Omar, a hospital-based internist who was not involved in her case. “I think these cases get admitted and treated, but the cause is never figured out. Luckily, it’s not very common.”
The fatigue began in July soon after Meredith, then 70, returned from her family’s annual reunion, an event that drew relatives from as far afield as Chile.
She began having difficulty completing her daily walk, and noticed brief palpitations. They didn’t alarm her. In her thirties, she had experienced similar irregular heartbeats when she was stressed; testing at the time had ruled out a serious problem.
“I’d always associated them with anxiety,” Meredith said. Although she did not feel anxious, she had just come back from a trip, and it was 37°C out.
Her grandson was staying with her for a week, and they relaxed by watching movies in the evening as Meredith snacked on some Dutch salt liquorice coins she had first tasted at the reunion.
On the afternoon of August 1, Meredith had a physical therapy appointment designed to treat a shoulder problem.
At the start of her appointment, a student took her blood pressure. The reading was unusually high: about 168/90; Meredith’s reading is usually about 100/60. Meredith said she assumed the elevated reading reflected the student’s inexperience.
“I asked her: ‘Are you sure your monitor’s working okay?’”
Meredith recalled that blood pressure reading as she considered what to do about her swollen ankles. She chewed an aspirin tablet, something a person suspected of having a heart attack should do to prevent platelets from clumping and blocking an artery. Then she called her daughter, who lives nearby, and told her to pick up her son.
“I knew I had to get to the hospital as soon as possible,” she said.
There she told a nurse in the ER: “I think I’m having a cardiac event.”
She was whisked by wheelchair to an examining bay.
Several hours later, after tests ruled out a heart attack, she began to relax. “I was surprised – and delighted,” she said.
She figured that a few intravenous bags of potassium would restore her count and that her blood pressure could be lowered with medication.
But Meredith’s doctors were concerned. Her systolic blood pressure, which measures pressure in the arteries when the heart beats, had risen to nearly 200 at one point, increasing her risk of a stroke. And her potassium level hovered at about 2.6, a condition called hypokalaemia, considered a medical emergency because it can trigger ventricular fibrillation, a wildly irregular heartbeat that can be fatal.
Doctors were perplexed by the cause of her sky-high blood pressure and hypokalaemia. Hypokalaemia has many causes, among them the use of diuretics (medicines used to treat high blood pressure); other causes include tumours, metabolic disorders, kidney disease and vomiting or diarrhoea that leads to dehydration.
Blood tests of Meredith’s levels of plasma renin, an enzyme that regulates blood pressure and kidney function, and aldosterone, a hormone produced in the adrenal gland, were abnormally low.
“People can die from low potassium,” said Dr Irmindra S Rana, a kidney specialist who was among the doctors who treated Meredith.
Meredith said she was repeatedly asked by her doctors and nurses whether she had taken diuretics or had suffered a recent bout of vomiting or diarrhoea; the answer to those questions was no.
On the second or third day of her hospitalisation, a second kidney specialist asked her a new question, one that commanded her attention.
“Have you eaten liquorice lately?” he asked.
Meredith said: “I sat up in bed and said ‘Yes! What does that have to do with it?’” Everything, it turned out.
Meredith told her doctors she had not just eaten a few black liquorice coins. A lifelong liquorice lover, she enjoyed the the sweets so much that after the reunion she had ordered two 1kg bags. And in the space of about a week after she returned home, she had eaten one of those bags herself. “My practice with forbidden goodies,” she said, “is to eat them as fast as possible” so they’re not around to tempt her.
The type Meredith had eaten is called salt liquorice and is popular in northern Europe. It contains glycyrrhizin, which causes it to taste sweet. The ingredient is made from liquorice root, consumption of which can prompt the kidneys to release too much potassium, disrupting cardiac function and sometimes causing palpitations. Glycyrrhizin is not present in red liquorice or in some liquorice-flavoured sweets that uses a sweetener other than liquorice root.
“We were looking for a unifying hypothesis” to explain her symptoms, said Rana, who made the diagnosis in conjunction with the other nephrologist and the hospital internist.
In the absence of other findings, patients with very high blood pressure, fatigue and very low potassium and who have consumed large quantities of liquorice are presumed to be suffering from liquorice poisoning. And eating a 1kg bag of liquorice in a short time is clearly enough to cause it.
“The key is to take a good history from patients,” said Rana, who said he had seen one other case of liquorice toxicity in his career.
In the US, the Food and Drug Administration in 2011 cautioned consumers to avoid overconsumption of black liquorice. The agency warned that people older than 40 who consumed too much black liquorice in a concentrated period could risk heart rhythm disturbances or muscle weakness. Sensitivity to glycyrrhizin varies and may be affected by genetic factors as well as sex and age.
The link between liquorice and metabolic problems goes back decades, said Omar, who has written two papers on liquorice poisoning.
Omar, who graduated from an Egyptian medical school, said the problem was not uncommon among Muslims during Ramadaan, when people are forbidden to eat or drink for 12 hours or more each day.
Some consumed enormous amounts of liquid liquorice – sometimes in the form of tea – to blunt thirst, he said, only to wind up in hospital. Patients who also take diuretics are particularly susceptible to accidental poisoning as are those who binge on liquorice.
After four days in the ICU, Meredith was discharged from the hospital; by then, her potassium level had returned to normal. Her blood pressure declined slowly but steadily, though it remained elevated for several months, as is common in cases of excess liquorice ingestion.
“I was dumbfounded by this,” Meredith said. “I certainly had never heard of it.”
Meredith, who saw Rana several times after discharge to monitor her blood pressure and kidney function, has recovered completely with no ill effects, as do most patients. She has not touched liquorice since.
The Washington Post