With winter slowly receding, the first signs of spring are emerging from the frost. For many people, this means more time spent outside in a t-shirt and shorts. However, this increased activity outdoors comes with some concerns.

Now experts are recommending that people be on the lookout for the brown recluse spider because of its bite, which can lead to sudden and inexplicable anemia. The native range of the brown recluse spider is from southeastern Nebraska through Iowa and Indiana, and into southwestern Ohio. It is also common in Texas, western Georgia, and into northern Virginia.

Recently doctors reported that healthy adolescents were admitted to the hospital with symptoms of anemia, which were linked to red blood cell destruction, or hemolytic anemia. The cases were traced back to bites from the brown recluse spiders. All of the patients made full recoveries, but three had to be admitted to the intensive care unit, and four of them needed blood transfusions.

One of the problems with these spider bites is that they are painless and often go unnoticed. In the current study, in three of the six cases, the bites were only discovered after full-body skin checks were conducted. It is important to keep in mind that medical attention may be necessary in about 30% of children bitten by the brown recluse. In rare instances, kidney failure and clotting problems can result.

Doctors stress that most people should not be overly worried about brown recluse spiders, but that the purpose of the information is more as a reference for doctors in order to determine the cause of acute anemia in their patients. The reasoning: Different causes of anemia call for different methods of treatment. So while some forms of anemia will respond to steroid therapy, that is not necessarily the case for spider bites, where standard care includes supportive treatment and attending to the wound. Currently, the efficacy of steroid therapy for spider bites is unproven.

Brown recluse spiders can be identified by the violin-shaped mark on its head and a penchant for seclusion under rocks or in dark corners. The spider keeps to itself and has no interest in mingling with humans. Any bites it inflicts are purely accidental and results when it feels threatened or through accidental contact.

If you have questions or concerns about anemia, or if you suspect that your child has been bitten by a spider, contact your pediatrician. For more information about brown recluse spiders, visit the website for brownreclusespider.org.