Summary about Disease
Favism is a genetic condition, specifically an enzyme deficiency of glucose-6-phosphate dehydrogenase (G6PD), that leads to hemolytic anemia after ingestion of fava beans (broad beans), certain other beans, or exposure to certain drugs or chemicals. Hemolytic anemia occurs when red blood cells are destroyed faster than they can be produced. The severity of favism varies widely depending on the specific G6PD variant and the amount of trigger consumed or encountered.
Symptoms
Symptoms of favism typically arise 24-48 hours after exposure to the trigger and can include:
Fatigue
Pale skin
Jaundice (yellowing of the skin and eyes)
Dark urine (tea-colored)
Dizziness
Shortness of breath
Rapid heart rate
Enlarged spleen
Abdominal pain In severe cases, favism can lead to kidney failure, shock, and even death.
Causes
Favism is caused by a deficiency in the enzyme glucose-6-phosphate dehydrogenase (G6PD). This deficiency is inherited, meaning it is passed down through families via genes. G6PD is crucial for protecting red blood cells from oxidative damage. Without enough G6PD, red blood cells become vulnerable and can be destroyed when exposed to certain substances, most notably compounds in fava beans (vicine and convicine), some medications (like certain antibiotics and antimalarials), and certain chemicals (like naphthalene in mothballs). It's more common in males as the G6PD gene is on the X chromosome. Females can be carriers or affected depending on which X chromosomes are affected.
Medicine Used
There is no specific "cure" for favism itself, as it's a genetic condition. Treatment focuses on managing the hemolytic anemia crisis:
Supportive Care: The primary approach is to manage the symptoms. This includes providing oxygen if needed, monitoring vital signs, and ensuring adequate hydration.
Blood Transfusion: In severe cases of anemia, a blood transfusion may be necessary to replenish red blood cells.
Medication Review: Identifying and discontinuing any medications that could be triggering the hemolytic reaction is crucial.
Rarely, Splenectomy: In very rare and recurrent severe cases, the spleen might be removed. There is no medication to increase G6PD levels.
Is Communicable
Favism is NOT communicable. It is a genetic condition, not an infectious disease. It cannot be spread from person to person through any means.
Precautions
The most important precaution for individuals with G6PD deficiency is strict avoidance of known triggers:
Dietary: Avoid fava beans (broad beans) and products containing them. Be aware of potential cross-contamination in food preparation.
Medications: Consult with a doctor or pharmacist before taking any medication, including over-the-counter drugs, to ensure they are safe for people with G6PD deficiency.
Chemicals: Avoid exposure to naphthalene (mothballs), certain dyes, and other chemicals known to trigger hemolysis in G6PD deficient individuals.
Inform Healthcare Providers: Always inform healthcare providers about the G6PD deficiency to prevent the administration of harmful medications.
Genetic Counseling: Consider genetic counseling if you have a family history of G6PD deficiency, especially if you are planning to have children.
How long does an outbreak last?
The duration of a favism outbreak (hemolytic crisis) varies depending on the severity of the G6PD deficiency, the amount of trigger exposure, and how quickly treatment is initiated.
Mild Cases: Mild reactions may resolve within a few days with supportive care and avoidance of the trigger.
Moderate to Severe Cases: More severe reactions can last for several days to weeks, requiring hospitalization, blood transfusions, and close monitoring. The body needs time to regenerate red blood cells. Full recovery, including the restoration of red blood cell count to normal levels, can take several weeks to a few months.
How is it diagnosed?
Favism (G6PD deficiency) is diagnosed through blood tests:
G6PD Enzyme Activity Test: This test measures the level of G6PD enzyme activity in red blood cells. Low levels indicate G6PD deficiency. The test may need to be repeated a few weeks after a hemolytic episode as enzyme levels can be falsely elevated during acute hemolysis due to the presence of younger red blood cells with higher G6PD activity.
Complete Blood Count (CBC): This test can detect anemia (low red blood cell count) and other abnormalities associated with hemolysis.
Reticulocyte Count: This test measures the number of immature red blood cells, which increases during hemolytic crises as the body attempts to compensate for the loss of red blood cells.
Bilirubin Levels: Increased bilirubin in blood can suggest red blood cell breakdown.
Urine Analysis: Detects hemoglobinuria (hemoglobin in the urine), indicating red blood cell breakdown.
Genetic Testing: While less common for initial diagnosis, genetic testing can identify the specific G6PD gene mutation.
Timeline of Symptoms
Exposure: Trigger exposure occurs (e.g., eating fava beans, taking an offending medication).
12-48 Hours: Symptoms may begin as early as 12 hours or as late as 48 hours after exposure.
24-72 Hours: Symptoms typically peak within 24-72 hours. Key symptoms like dark urine, jaundice, fatigue, and shortness of breath become more pronounced.
Several Days: Symptoms persist for several days. The severity depends on the exposure amount, and G6PD variant.
Weeks to Months: Recovery takes weeks to months for red blood cell levels to return to normal.
Important Considerations
Variability: The severity of G6PD deficiency varies greatly depending on the specific genetic mutation and the individual's overall health.
Carrier Status: Females can be carriers of the G6PD deficiency gene without showing symptoms, but they can still pass the gene on to their children. They might also experience mild symptoms in some cases.
Neonatal Jaundice: G6PD deficiency can cause severe jaundice in newborns, potentially leading to brain damage (kernicterus) if left untreated. Newborn screening for G6PD deficiency is crucial in areas where the condition is prevalent.
Drug Interactions: It is crucial to consult with a healthcare professional before taking any medication to ensure it is safe for people with G6PD deficiency. Many medications can trigger hemolysis.
Lifelong Management: G6PD deficiency is a lifelong condition that requires ongoing vigilance in avoiding triggers. Regular check-ups with a doctor are important for monitoring overall health and managing any potential complications.