Favism - Causes, Symptoms, and Treatment

Introduction

Favism is also known as acute hemolytic anemia. Anemia is when blood is insufficient to meet the body's oxygen requirement. Hemolytic anemia refers to the premature destruction of red blood cells (RBC), causing a short life span for RBC. The function of RBC is to carry oxygen to meet the body's requirements. The short life span of RBC results in insufficient blood supply to the body resulting in acute hemolytic anemia. Glucose-6-phosphate dehydrogenase (G6PD) is the predisposing factor for favism. Favism occurs commonly where the frequency of glucose-6-phosphate dehydrogenase (G6PD) deficiency is relatively high. The incidence of favism is high in West Africa. Although the incidence of favism is not known precisely, favism has been recorded in 35 nations, and over 3000 cases are reported. Favism is a life-threatening condition mostly affecting children. A full recovery from favism is expected with proper management, which often must include blood transfusion and prompt diagnosis.

What Is Favism?

Favism is also known as acute hemolytic anemia, as fava beans trigger hemolytic anemia. Fava beans are also known as broad beans, grown in Northern Germany. Fava beans are popular food items. Acute hemolytic anemia is referred to as premature destruction of the RBC, resulting in insufficiency to meet the body’s oxygen requirement. Acute hemolytic anemia is a genetic disorder caused due to glucose-6-phosphate dehydrogenase (G6PD) deficiency. The commonest trigger factor for acute hemolytic anemia (AHA) is fava bean ingestion causing favism. Glucose-6-phosphate dehydrogenase (G6PD) is an enzyme that protects against oxidative damage of RBC. Oxygen is one of the most reactive oxygen species. The oxidative damage to red cells causes both intravascular (inside the blood vessel) and extravascular (outside the blood vessel) hemolysis. Favism can be a life-threatening condition if not promptly diagnosed.

What Are the Causes of Favism?

Favism is known as acute hemolytic anemia. Acute hemolytic anemia is caused due to mutation (alternation in the original structure of the genetic material) in the gene and glucose-6-phosphate dehydrogenase deficiency. Several studies suggested that glucose-6-phosphate dehydrogenase deficiency occurs due to a gene mutation triggered by drugs and ingesting fava beans. The following are the causes of favism:

• Genetic factors cause glucose-6-phosphate dehydrogenase deficiency resulting in acute hemolytic anemia. For example, gene mutation in the G6PD gene causes glucose-6-phosphate dehydrogenase deficiency.

• Glucose-6-phosphate dehydrogenase enzyme deficiency.

• Hemolytic anemia is observed in primaquine-taking patients (persons referred to as "primaquine sensitive").

• Full-blown favism can occur in breastfeeding newborns baby whose mother has a history of ingestion of fava beans.

• The anti-malarial drug (Dapsone-containing anti-malarial drug Lapdap) can cause G6PD deficiency. However, there is a common belief that drug-induced acute hemolytic anemia is the predominant cause of glucose-6-phosphate dehydrogenase deficiency.

• The ingestion of fava beans (broad beans) is the cause of glucose-6-phosphate dehydrogenase deficiency. The commonest triggering factor of glucose-6-phosphate acute hemolytic anemia is fava beans.

What Are the Signs and Symptoms of Favism?

Generally, the patient of favism is children around two years to ten years. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is asymptomatic until it is severe.

The acute hemolytic anemia symptoms that can be noted in favism are as follows:

• Patients appear blue in appearance, also known as a favism attack. The blue appearance is due to a lack of red blood cells in the body (anemia).

• Pale skin or face.

• Yellowing of skin, nails, and eyes (jaundice).

• Abdominal pain.

• High fever.

• Severe anemia.

• Weight loss.

• Weakness.

• Confusion.

• Increase heart rate (tachycardia).

• Fatigue.

• Inability to do any physical task.

Signs

• Dark urine.

• Splenomegaly (enlargement of the spleen).

• Hemoglobinuria (presence of hemoglobin in the urine).

• Tachycardia.

• Alteration in the sound of heartbeat (heart murmur).

How Is Favism Diagnosed?

Favism is a life-threatening condition that occurs in children. Urgent hospital admission is required in the case of favism. The diagnosis of favism is based on three factors, usually present in all cases. The three findings in patients with favism are anemia, jaundice, and a history of fava bean ingestion. The following are the sequelae to diagnose favism:

• History - The history of patients with favism reveals the ingestion of fava beans.

• Physical Examination - On physical examination, signs, and symptoms of favism are confirmed, such as abdominal pain. On palpation, doctors can observe an enlarged spleen and suggests further examinations. In addition, the patient with favism shows a low oxygen saturation level on examination.

• Blood Tests - The total blood count can detect a low count of RBC, indicating anemia. On further blood examination, Heinz bodies (large aggregates of denatured hemoglobin) can be found. The bilirubin level is always elevated in patients with favism, indicating jaundice.

• Urine Test - The urine is often dark in patients with favism. Urine tests are positive for the presence of hemoglobin in the urine (hemoglobinuria).

• Biochemical Test - The patient with favism are detected with glucose-6-phosphate dehydrogenase deficiency on biochemical tests.

How Is Favism Treated?

The management of favism is not challenging once a prompt diagnosis is made. However, favism is a life-threatening condition if it is not promptly diagnosed. In mild cases, quick hydration and symptomatic care are sufficient. Hospitalization is necessary for more severe cases of acute hemolytic anemia. Severe cases of favism in children or adults require immediate medical attention, with blood transfusions as the cornerstone.

The following are the treatment options for favism:

• The children with AHA admitted with low hemoglobin (below 8 g/dl) require blood transfusions, according to the protocol of the hospitals. In all cases, the need for blood transfusions is reassessed even after recovery.

• For severe cases of favism in which patients suffer from kidney failure, hemodialysis may be necessary.

• The symptomatic treatment of jaundice is advised.

• Iron supplements and improvement in dietary supplements are recommended.

Conclusion

Favism can be prevented in children with glucose-6-phosphate dehydrogenase deficiency. Children with G6PD deficiency should be refrained from eating fava beans. Without screening, affected children or adults cannot be diagnosed with low G6PD. Hence, screening, intervention, and proper education of the people and cultivators of fava beans are required to prevent favism. The concept of newborn screening and health education lowered the incidence of favism. In addition, the full recovery of favism is expected with proper medical intervention and prompt diagnosis.