Ocular filariasis manifesting as an orbital cellulitis and conjunctival nodule: a case report

Filariasis is a parasitic infection that mostly involves the skin and ocular surface, although all layers of the eye and orbit can be affected. We report a case of a 42-year-old woman with Loa loa infection manifesting as a sequential bilateral forehead Calabar swelling, severe orbital cellulitis and thereafter mimicking a conjunctival tumor. Anterior segment optical coherence tomography helped to differentiate between a neoplasm and the filarial worm and show typical features such as longitudinal and cross-sections of the parasite. The worm was surgically removed and microbiologists confirmed the diagnosis of a subconjunctival Loa loa infection. The patient was successfully treated with diethylcarbamazine (DEC) and ivermectin without adverse events. Parasitic orbital cellulitis is rarely reported and this case highlights the importance of considering loiasis in unexplained orbital cellulitis in patients with hypereosinophilia and a history of residence in endemic areas.