Cerebrospinal fluid analysis in these patients has shown elevated protein without pleocytosis. 109 Centrally, magnetic resonance imaging shows hyperintense T2 lesions in the subcortical white matter, and autopsy has documented white matter necrosis and demyelination in multiple areas of the brain, spinal cord, and optic nerves. Antimyelin antibodies have been isolated. When peripheral nerves are affected, nerve conduction studies reveal increased latencies and absent F waves. 108 Clinically, patients may present with quickly progressive motor weakness and areflexia, paresthesias, encephalopathy, or vision changes associated with optic neuritis. 107 Multiple reports are available describing acute demyelinating syndromes affecting both the CNS and the peripheral nervous system. Interestingly, many reports are available describing pure neurological dysfunction that appears days to weeks following a single envenomation, leading to the suggestion that there may be a delayed immunological response or hypersensitivity reaction component to the illness. 150, 106 Typically, these symptoms are immediate and often in the context of IgE-mediated reactions. Repetitive stimulation showed decremental response, and in one case the patient was treated with an acetylcholinesterase inhibitor. 91, 103, 104 Others have reported bilateral ptosis and a clinical picture similar to myasthenia gravis following wasp sting. Reported neurological symptoms include local paresthesias, headache, dizziness, nausea and vomiting, muscle aches, and rarely, cerebrovascular infarcts. Honeybee colonies typically reach up to 40,000 workers, which can inflict thousands of stings, and systemic toxic reactions are more likely to occur following envenomation by only 50 or more wasp stings. Mass envenomations pose a greater threat for systemic reactions from increased venom load. The most common lethal reaction to a single hymenopteran sting involves IgE-mediated anaphylaxis and resultant pulmonary edema, intravascular hemolysis, renal failure, and shock. ![]() Honeybees sting only once before the stinger falls off, but wasps may sting multiple times. Postma, in Clinical Neurotoxicology, 2009 Clinical Presentation The external sclerotised parts are structured for stinging through muscular action while the unsclerotised structures secrete the venom. The stinging apparatus comprises several interconnected sclerotised (hard) external parts including the sting and several interconnected unsclerotised (soft) internal parts containing the poisons sac, the acid glands, and the alkaline gland. ![]() The sting is used for offence and defence. The male wasps and bees do not possess stings but have mandibles that can bite. The sting is a modified ovipositor (egg-laying tube) and is therefore only found in the female. The bee sting always includes the sting and venom gland in the wound unless brushed off, while the hornet sting leaves only a puncture mark, which is usually larger than that made by the bee sting. Therefore, they are able to sting their victims repeatedly without having to lose their stings and die. ![]() Wasps, on the other hand, have unbarbed stings. The bee sting is barbed at the end like a fish hook, thus it is always left behind in the wound resulting in the subsequent death of the bee. Gopalakrishnakone, in Human Toxicology, 1996 Stings The risk of a serious reaction is low, and most patients successfully complete the course.P.
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