Ocular complications of oak processionary caterpillar setae in the Netherlands; case series, literature overview, national survey and treatment advice

Exploring oak processionary caterpillar induced lepidopterism (part 2): ex vivo bio-assays unmask the role of TRPV1

As human skin comes into contact with the tiny hairs or setae of the oak processionary caterpillar, Thaumetopoea processionea, a silent yet intense chemical confrontation occurs. The result is a mix of issues: skin rashes and an intense itching that typically lasts days and weeks after the contact. This discomfort poses a significant health threat not only to humans but also to animals. In Western Europe, the alarming increase in outbreaks extends beyond areas near infested trees due to the dispersion of the setae. Predictions indicate a sustained rise in outbreaks, fueled by global changes favoring the caterpillar's survival and distribution. Currently, the absence of an efficient treatment persists due to significant gaps in our comprehension of the pathophysiology associated with this envenomation. Here, we explored the interaction between the venom extract derived from the setae of T. processionea and voltage- and ligand-gated ion channels and receptors. By conducting electrophysiological analyses, we discovered ex vivo evidence highlighting the significant role of TPTX1-Tp1, a peptide toxin from T. processionea, in modulating TRPV1. TPTX1-Tp1 is a secapin-like peptide and demonstrates a unique ability to modulate TRPV1 channels in the presence of capsaicin, leading to cell depolarization, itch and inflammatory responses. This discovery opens new avenues for developing a topical medication, suggesting the incorporation of a TRPV1 blocker as a potential solution for the local effects caused by T. processionea.

Ocular Injuries Due to Insect Spines (Ophthalmia Nodosa): Potential Hazard to Motorcyclists

Ocular injury remains a potential hazard to motorcyclists. While the incidence of traumatic penetrating or blunt ocular injury is widely known in the literature, ocular injuries due to insect hair or spine (ophthalmia nodosa) among motorcyclists are scarce or unheard of. Here, we report four cases of ocular injuries caused by insect hair spines among motorcyclists. Patients consist of three males and one female with ages ranging from 18 to 24 years. All patients presented with unilateral ocular irritation after a history of insect entry into the eye while riding a motorcycle. Visual acuity upon presentation ranged from 6/6 to 6/60. Penetration of setae into the cornea and anterior chamber reaction was found in all patients. Complete removal of cornea setae was not possible in all patients. Immediate treatment with topical antibiotics and corticosteroids was administered and continued for one to three months. All patients recovered well attaining a vision of 6/6 to 6/9. In conclusion, ophthalmia nodosa among motorcyclists is a preventable ocular hazard with the appropriate use of a visor or protective eyewear. Immediate treatment may prevent severe ocular complications.