As spring approaches and people return to outdoor activities, caution should be taken in areas of the country that are home to Loxosceles reclusa, also called the brown recluse spider. A new study from St. Jude Children's Research Hospital found that when patients present with sudden anemia, but the cause is elusive, the brown recluse spider should be part of the differential diagnosis, at least in parts of the nation where the spider is regularly found.