Halzoun syndrome in Lebanon: Clinical and genetic insights into Dicrocoelium dendriticum

Halzoun syndrome is a rare parasitic infection associated with the consumption of raw liver, predominantly reported in the Eastern Mediterranean. The condition presents significant diagnostic challenges due to its symptom overlap with other parasitic and allergic disorders. We identified four cases of Halzoun syndrome in a family from the North Bekaa region of Lebanon. A detailed examination of the goat liver was conducted, followed by molecular characterisation using the ITS-2 region and phylogenetic analysis to establish the relationship of the local isolates with other Dicrocoelium species. Gross examination of the infected goat liver revealed small, pale nodules indicative of inflammation caused by flukes or their eggs. Molecular analysis confirmed D. dendriticum as the causative agent, with phylogenetic analysis placing the local isolates within the D. dendriticum clade, showing notable genetic divergence. Clinically, the patients experienced severe pharyngitis, nasal congestion, and allergic-like reactions typical of Halzoun syndrome, with one case requiring intensive treatment with corticosteroids and oxygen therapy. This study confirms D. dendriticum as the etiological agent of Halzoun syndrome in these cases, highlighting the potential presence of a distinct genetic lineage in Lebanon. The findings underscore the importance of accurate diagnosis and tailored treatment strategies in regions where raw liver consumption is common.