It is not every day that a healthy 28-year-old woman presents with a gradually expanding mass in the inside corner of her left eye, prompting clinicians to investigate the root cause. This particular patient had been on a humanitarian mission in the Democratic Republic of Congo and reported the appearance of a lump 2 years ago, which had been increasing in size ever since. Upon further history-taking, it was revealed that she had no history of eye injury, no other accompanying symptoms, and no contact with snakes. However, she did have a regular diet that included crocodile meat. A physical examination unveiled a subconjunctival foreign body in the inner canthus of the eye – a finding that led to a series of investigative procedures.
The team of clinicians proceeded with a conjunctival incision, which led to the extraction of a 10-mm C-shaped larva with several annulations. This larva, identified as Armillifer grandis, was subsequently sent for testing at the National Reference Center of Tropical Pathogens in Germany. The use of polymerase chain reaction (PCR) primers targeting the nuclear 18S RNA gene of the pentastomid confirmed the diagnosis. It is worth noting that pentastomiasis is a rare zoonotic disease caused by the larval stages of pentastomid parasites, which typically affect individuals in tropical and subtropical regions. The treatment of choice for such cases involves surgical removal of the larvae, as the usage of antiparasitic medication may induce a strong immune response due to the release of antigens from dying larvae.
Infections like pentastomiasis, particularly those involving the eye, are rare occurrences that often go undiagnosed due to their asymptomatic nature. However, when symptoms do arise – such as migration, organ perforation, or death of the larvae – they can elicit a robust immune reaction. The consumption of undercooked reptile meat and close contact with parasitized snake hosts are common risk factors associated with Armillifer infections. To prevent such infections, individuals are advised to avoid these risk factors and maintain strict hygiene practices. While there is no serological test currently available for pentastomiasis, diagnostic methods such as PCR targeting specific parasite genes prove to be reliable, albeit challenging to access in rural endemic regions with limited resources.
Ocular pentastomiasis, especially due to Armillifer grandis, is a rare phenomenon that requires careful consideration by clinicians and ophthalmologists alike – particularly in individuals with a history of travel to endemic regions. This case study sheds light on the importance of thorough history-taking, clinical examination, and prompt diagnosis in unveiling rare parasitic infections of the eye. Moving forward, a greater awareness of such conditions, along with preventive measures and accessible diagnostic tools, is essential in managing and preventing cases of ocular pentastomiasis in clinical practice.
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