Approach and management of spider bites for the primary care physician

The class Arachnida of the phylum Arthropoda comprises an estimated 100,000 species worldwide. However, only a handful of these species can cause clinical effects in humans because many are unable to penetrate the skin, whereas others only inject prey-specific venom. The bite from a widow spider will produce local symptoms that include muscle spasm and systemic symptoms that resemble acute abdomen. The bite from a brown recluse locally will resemble a target lesion but will develop into an ulcerative, necrotic lesion over time. Spider bites can be prevented by several simple measures including home cleanliness and wearing the proper attire while working outdoors. Although most spider bites cause only local tissue swelling, early species identification coupled with species-specific management may decrease the rate of morbidity associated with bites.