PUBLICATION EXCLUSIVE: Chemotherapy can suppress inflammatory signs of periocular filariasis

Dirofilariarepens is an endemic parasite in Mediterranean countries that mostly affects animals. Dirofilaria is a genus of the family Onchocercidae of the super family Filarioidea, order Spirurida in the subphylum Nematoda. Rarely, it can infect humans, causing inflammatory subcutaneous swelling. Human ocular dirofilariasis is sporadically reported in different parts of the world. The species affecting humans are D. immitis, D. repens, D. striata, D. tenuis, D. ursi and D. spectans. The most common presentation is an inflammatory swelling of the ocular adnexa. We report a non-inflammatory presentation of dirofilariasis in the lid mimicking as lipoma in a patient on cancer chemotherapy.A 67-year-old man presented with complaints of painless swelling in the lower lid of the right eye, with the swelling gradually increasing in size. Best corrected visual acuity was 6/9 in the right eye and 6/6 in the left eye. Other ocular findings were within normal limits, except for a history of cataract surgery. He was a known case of carcinoma bladder treated with chemotherapy. There was no history of pain, tenderness or fever. There was no history suggestive of moving worms feeling. Ocular examination showed a swelling size of 2 cm × 2 cm (Figure 1). On palpation, the swelling was non-tender, well-defined, soft to firm in consistency and freely mobile in all directions. The differential diagnosis considered was a lipoma, and excision biopsy was undertaken.