BACKGROUND AND OBJECTIVES: The etiology of favism remains unclear and the fate 
of favic patients has not previously been studied. Therefore, individuals who 
had experienced an episode of favism were studied regarding subsequent fava bean 
ingestion, including the reason for fava bean ingestion after the initial favic 
attack and any adverse reactions. In addition, a new hypothesis for the etiology 
of favism is proposed.
PATIENTS AND METHODS: From June 2005 to June 2012, a total of 38 patients with a 
history of favism were included in this study. Circumstances regarding the 
initial favic attack were obtained from medical records and patient interviews, 
and subsequent fava bean ingestion and recurrence of symptoms were investigated.
RESULTS: Three of the 38 patients (7.9%) were female, and 35 (92.1%) were male. 
The mean age was 27.9 years (14-63 years). The first attack of favism occurred 
before 10 years of age for 31 patients (81.6%) and in the springtime for 35 
patients (92.1%). Thirty-three patients (86.7%) regularly ate fava beans before 
the attack, and 35 (92.1%) resumed eating fava beans within 1-17 years after the 
attack without symptoms. Two patients (5.2%) experienced a single recurrence of 
symptoms. No evidence of hemolysis was found in the four patients checked after 
fava bean re-ingestion.
CONCLUSIONS: Patients resumed eating fava bean for various reasons, and the 
recurrence of symptoms was uncommon. An infectious agent such as a virus may 
play a role in the development of favism.