![]() ![]() 8ĭirect stings to the ocular surface, including the cornea or conjunctiva, occur less commonly, but are far more serious. In such cases, not only is a venomous reaction possible, but also the disembodied stinger may damage the corneal surface. The area may be indurated (e.g., firm and nodular) around the site of inoculation, and the retained stinger may be visible.ĭirect injuries to the lid may involve penetration of the tarsus. ![]() Redness, edema and lacrimation are the hallmarks of this type of injury. The lids and adnexa are most commonly involved, and patients typically present with an acutely painful, swollen eye. Sting injuries can affect a variety of ocular structures. Kabat at Review of Optometry’s annual continuing education meeting in Maui!) Honeybees can pose a significant risk to ocular health in cases of sting injuries to the eye or adnexa. 6,7 Anaphylaxis due to insect venom is exceedingly rare, occurring in less than one in 15,000,000 cases annually. According to the literature, only about 1% to 9% of adults experience systemic reactions to bee stings children are even less likely to manifest these responses. ![]() Systemic allergic reactions can also be seen in hypersensitive individuals, although the prevalence of these allergies is actually quite low. 2,4 With prolonged exposure to the retained stinger, chronic inflammation-as well as secondary local tissue degradation-may ensue. Components of the venom induce an acute response at the inoculation site that involves vasodilation, tissue edema and leukocyte chemotaxis. The mechanical trauma and toxic effects of insect venom combine to initiate an inflammatory cascade in the victim of a sting injury. 2,3 Enzymes, including phospholipase A, hyaluronidase and phosphodiesterase, further exacerbate local damage by perpetuating the immune response. Major peptides, such as apamin, bradykinin and melittin, cause cellular damage and disruption of normal metabolic processes, and can serve as potent neurotoxins. Amines (e.g., histamine and dopamine) cause an immediate pain response, presumably to deter further invasion or insult to the insects’ territory. The venom of stinging insects is composed primarily of biogenic amines, polypeptides and enzymes. In the act of stinging, a highly toxic, species-specific venom is injected and actively pumped into the tissue of the adversary. The aculeus is attached to a venom sac that is located at the base of the insect’s abdomen. So, sting injuries to the ocular structures often result in a puncture wound and a foreign body insult. While wasps, hornets and bumblebees do not possess a barbed stinger, portions of this structure may occasionally break off and remain in the tissue. Thus, this structure (and the associated venom sac) is forfeited, resulting in the insect’s death. The honeybee’s aculeus is barbed and cannot be withdrawn after an attack. The stinger is composed of chitin-a tough, keratin-like substance that is the principle component of arthropod exoskeletons. Therefore, only female insects are capable of producing sting injuries. The aculeus or “stinger” of bees and wasps (order: Hymenoptera) is a modified ovipositor. In general, injuries from bee stings may be categorized as mechanical, toxic and/or immunologic. Sting injuries have long been recognized as a significant source of ocular trauma.1 Bee and wasp stings can directly initiate a variety of ocular manifestations, as well as yield secondary systemic repercussions. This month’s column deals with the unusual, but very real, dilemma of managing ocular sting injuries from bees, wasps and other flying insects. Recently, the following post came to our attention: “Help! What do you do for a bee sting in the eye? I was just now mowing the lawn when I was dive-bombed by a bee that stung me right on the upper eyelid.” Although it may seem unthinkable to many of us in healthcare, patients sometimes seek medical advice from online communities, such as Facebook or Yahoo!, before contacting their doctors. ![]()
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