{"id":83,"date":"2011-07-15T13:56:40","date_gmt":"2011-07-15T13:56:40","guid":{"rendered":"https:\/\/blogs.nature.com\/spoonful\/2011\/07\/medical-experts-grapple-with-an-eight-legged-problem.html"},"modified":"2011-07-15T13:56:40","modified_gmt":"2011-07-15T13:56:40","slug":"medical_experts_grapple_with_a","status":"publish","type":"post","link":"https:\/\/blogs.nature.com\/spoonful\/2011\/07\/medical_experts_grapple_with_a.html","title":{"rendered":"Medical experts grapple with an eight-legged problem"},"content":{"rendered":"

Snake bite treatments have been all the rage of late here at Nature Medicine<\/em>. This month, we have a podcast interview<\/a> with the author of a recent paper<\/a> who found that applying an off-the-shelf ointment can slow the spread of snake venom. Last summer, we reported<\/a> how drug companies aren\u2019t developing new antivenom therapies despite the medical need. And dipping into the archive, five years ago we published a commentary<\/a> on the role that the immune system\u2019s mast cells play in inactivating snake toxins.<\/p>\n

But snakes aren\u2019t the only vermin with a venom-filled bite. Each year hundreds of thousands of people<\/a> around the world are bitten by venomous spiders. Some of these, such as the redback spider<\/a> of Australia, cause neurotoxic effects, leading to cramps, nausea, paralysis and even death. Others, including North America\u2019s brown recluse spider (pictured at right), have cytotoxic venom that kills cells and tissue leading to nasty, ulcerated wounds.<\/p>\n

As such, one might think that spider antivenoms, which have been on the market for over half a century, could go a long way to treating the effects of these eight-legged onslaughts. But in practice, antivenoms are largely ineffective because spider bite victims often don\u2019t know for many hours that they\u2019ve been nipped. This means that bite victims generally fail to seek medical help fast enough for these treatments to make a difference, two spider bite experts argue in a report<\/a> out this week in The Lancet<\/em>.<\/p>\n

\u201cAntivenom is never going to be of any practical value because you can\u2019t administer in a way that\u2019s going to work,\u201d says study coauthor Geoff Isbister<\/a>, a clinical toxicologist at the University of Newcastle in Australia. \u201cIf this was a drug developed in the last 20 years it would never have got through\u201d regulatory scrutiny, he adds.<\/p>\n


\nThree years ago, Isbister and his colleagues published the results of a 126-person randomized trial conducted at 11 Australian hospitals that tested two different routes of antivenom administration to treat redback widow bites. Reporting<\/A> in the journal QJM<\/em>, they found little added benefit of antivenom over placebo.<\/p>\n

Others have had better outcomes. In a smaller, placebo-controlled trial involving an experimental antivenom called Analatro, Richard Dart<\/a>, director of the Rocky Mountain Poison and Drug Center in Denver, and his colleagues showed that the drug, developed by Mexico\u2019s Bioclon Institute, effectively combat black widow bites even though the subjects in the trial only received the treatment 10 hours, on average, after being bitten. \u201cWe didn\u2019t get them that early,\u201d says Dart. Nonetheless, “our results in just 24 patients were quite promising.\u201d They are now conducting a larger phase 3 follow-up<\/a>.<\/p>\n

A tangled web<\/strong><\/p>\n

Medicine\u2019s problem with treating spider bites is not just restricted to effective antivenom. As Isbister and Hui Wen Fan of the Butantan Institute in S\u00e3o Paulo, Brazil note in their new Lancet <\/em>paper, physicians often mistakenly ascribe necrotic skin lesions to the arachnid attackers instead of the true culprits, such as chemical burns, bacterial infections and Lyme disease. \u201c\u2018Spider bite\u2019 is a sexy diagnosis,\u201d says entomologist and brown recluse spider expert Rick Vetter<\/a> of the University of California-Riverside. \u201cIt\u2019s really kind of amazing how sloppy the medical literature is in this area.\u201d<\/p>\n

To explore this problem, Jeffrey Suchard, a professor of clinical emergency medicine at the University of California\u2013Irvine Medical Center, tracked 182 people who came into his hospital over a two-year period complaining of spider bites. Reporting<\/a> in the Journal of Emergency Medicine<\/em>, he found that seven were diagnosed with actual spider bites, nine with bites from other animals and the vast majority with infections, mostly from methicillin-resistant Staphylococcus aureu<\/em>s.<\/p>\n

Suchard allows that many of these seven spider bite diagnoses could be incorrect as spider bites are uncommon in Southern California. But, he notes, since doctors often incorrectly prescribe antibiotics for spider bites, in all likelihood \u201cthey turned out to have done the correct treatment despite themselves.\u201d<\/p>\n

Not all misdiagnoses turn out so well, though. Many people incorrectly identified with spider bites fail to receive proper treatment for their true ailment in a timely fashion. What\u2019s more, these people often unnecessarily receive antivenom drugs, which can cause allergic reactions. Around 20 years ago, one person even died<\/a> of severe lung spasms after receiving antivenom.<\/p>\n

The solution to all these problems, according to Laura James<\/a>, a pediatrician at the University of Arkansas for Medical Sciences in Little Rock, who, in May, reported<\/a> on the complications seen from brown recluse spider bites in children: \u201cWe just need better research to be able to recognize these lesions.\u201d<\/p>\n

Image of brown recluse spider via the CDC \/ Ohio State University<\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

Snake bite treatments have been all the rage of late here at Nature Medicine. This month, we have a podcast interview with the author of a recent paper who found that applying an off-the-shelf ointment can slow the spread of snake venom. Last summer, we reported how drug companies aren\u2019t developing new antivenom therapies despite the medical need. And dipping into the archive, five years ago we published a commentary on the role that the immune system\u2019s mast cells play in inactivating snake toxins.  Read more<\/a> Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":40,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-83","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/posts\/83","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/users\/40"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/comments?post=83"}],"version-history":[{"count":0,"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/posts\/83\/revisions"}],"wp:attachment":[{"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/media?parent=83"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/categories?post=83"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.nature.com\/spoonful\/wp-json\/wp\/v2\/tags?post=83"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}