If you feel feverish or dizzy after eating broad beans, don’t be careless and be alert to “favism”!

Review expert: Mao Xinmei, Chief Physician of Pediatrics, Ningxia Women and Children’s Hospital, Peking University First Hospital

Broad beans are a nutritious bean that is full-bodied and light green when mature. It not only tastes fresh and tender, has a fragrant flavor, but is also rich in protein, vitamins and other nutrients.

Broad bean source | pixabay

But not everyone is suitable to enjoy this delicacy. Some people will suffer from anemia, fever and other symptoms after eating broad beans , and in severe cases, their lives are even in danger. There was once news that a 6-year-old child was admitted to the ICU because of eating broad beans. At this time, broad beans have turned from a delicacy into a deadly "poison".

Source of favism | Tencent

Why is this? Today, let us learn about the past and present of "favism".

1

What is favism?

Favism, medically known as glucose-6-phosphate dehydrogenase deficiency (G-6-PD) , usually develops within 12-24 hours after eating fresh broad beans or broad bean products, or directly touching broad bean pollen, and may also cause discomfort a few days later.

In the early stages of favism, patients will experience fever, dizziness, loss of appetite, fatigue and other symptoms similar to allergies, which will make most people think that the patient is allergic to broad beans and not pay enough attention to it. Afterwards, symptoms such as anemia and hemoglobinuria will appear, the patient's urine will appear "black", the body temperature will gradually rise, and the various early symptoms will become more severe and can last for about 3 days. If it occurs at the same time as hemolytic anemia, it will cause vomiting, diarrhea and increased abdominal pain, liver enlargement, abnormal liver function and other symptoms. Severe cases may also cause coma, acute renal failure , and even death from multiple organ failure.

Favism is a genetic disease caused by a gene mutation that leads to a lack of glucose-6-phosphate dehydrogenase in the human body. The patient's red blood cells become sensitive due to the lack of this enzyme, and their reducing properties are damaged to a certain extent. When they encounter the fava amine in broad beans, they will induce oxidation of the red blood cell membrane and produce a hemolytic reaction . When the red blood cell membrane is damaged, the core part of the red blood cell, hemoglobin, will flow out of it, and the red blood cells will not work normally. Most of the red blood cells are destroyed, leading to hemolytic anemia.

2

How does favism occur?

About 90% of patients with favism, a common clinical disease, are boys under the age of 5. Why is this?

The main cause of favism is G-6-PD deficiency, which is an X-linked incomplete dominant genetic disease . There are significantly more male patients than female patients. Male patients carrying this gene have significantly reduced enzyme activity. Because female patients have two Xs, the symptoms are usually not serious.

The male sex chromosomes are composed of an X chromosome and a Y chromosome. The X chromosome comes from the mother. If the mother happens to carry the disease-causing gene on this chromosome, the boy will suffer from favism. That is to say , boys born to mothers with favism have a 50% chance of being patients and a 50% chance of being healthy. For girls, half are healthy and half are carriers . Carriers rarely get the disease or the symptoms are very mild and are often ignored. This is why most favism patients are concentrated in boys.

3

How to prevent and treat favism

Based on current research on favism, there is currently no special treatment, and only effective prevention can fundamentally eliminate the occurrence of favism.

First of all, we should do a good job of neonatal disease screening . Neonatal disease screening is an effective method for early prevention of G6PD deficiency and avoiding complications such as severe jaundice and hemolysis, and it has been widely recognized internationally. At present, most parts of China are screening newborns for this disease. The specific method is to collect heel blood 48 hours after birth, measure the G-6-PD enzyme activity , confirm suspected positive patients, and prevent them early.

Secondly, children with favism should not be allowed to eat broad beans . It should be noted that there are many ways to ingest broad beans. Eating raw, cooked, dried or fresh broad beans and broad bean products, inhaling broad bean pollen can induce favism. Breast milk after eating broad beans can also cause the baby to become ill. This is the most direct and important way to prevent it, so special attention should be paid.

Blood test source | pixabay

At the same time, be careful to eat less bitter melon, peanuts and some beans , because the red blood cells of people with this disease are damaged, and the intensity of the patient's symptoms is related to the oxidative strength of the stimulus. These foods contain oxidative substances, which can also cause favism, so they should be properly controlled and avoid eating too much.

You should also be especially careful when taking medication. Some Chinese herbal medicines that can cause favism should not be taken , such as the common honeysuckle and bezoar. Some antipyretic analgesics (aspirin, acetaminophen, etc.), antimalarial drugs, and antibacterial drugs (sulfonamides, etc.) should not be used. Camphor balls containing naphthalene should also not be used.

Blood bag source | pixibay

In case of severe hemolysis, timely blood transfusion is the most important relief method . At this time, red blood cells will dissolve and rupture after the disease, and can no longer work normally, leading to severe anemia, so timely blood transfusion is needed; in addition, more water is needed, because after the red blood cells rupture, the hemoglobin will flow out, and the ferrous ions and plasma proteins carried in it will increase the concentration of substances in human body fluids, thereby increasing the osmotic pressure of human body fluids, causing a series of symptoms such as renal failure and potassium poisoning, so timely fluid replacement is also one of the treatment methods.

When it comes to favism, the most important "prevention" method is early screening and prevention. Patients should avoid eating foods related to favism in their daily lives to prevent accidents.