Ocular Lesions Produced By Pine Processionary Caterpillar Setae (Thaumetopoea Pityocampa)

Clinical case of a work-related injury of a gardner who entered in contact with a processionary caterpillar in his left eye. The patient was followed over a period of six months.

Ophtalmology Unit, Departement of Medical, Surgerical and Neurosciences of Siena University, Italy

The patient was evalued with BCVA, slit lamp examination with photos and confocal microscopy images.

Initial BCVA was 20/100 with severe hyperemia, corneal haze and numerous setae in the corneal epithelium and stroma. The first day a therapeutical scraping was performed to remover the most superficial setae. Medical therapy with double topical antibiotics, iodopovidone and steroid was started. The patient was evaluated dayly for the first week, then weekly for a month, and other controls were made approximately every 2-3 weeks. After the first three weeks, only an association of tobramicyn/dexamethasone was prescribed. The therapeutical scraping was performed another time. After six month, BCVA was restored at 20/20. A minimal presence of processionary setae is still visible 

Processionary caterpillar can cause severe disease in the eye, in particular due to the ability of the setae to penetrate the cornea. Despite this, no signs of infection were found and, apart from manual removal, most of these setae were slowly degraded from the patient's cornea, thus resulting in a good prognosis. Although it is a rare lesion in humans, it is important to know its clinical aspect and its possible  evolutions to ensure a prompt treatment.