Dissecting the Arthropod Assault 

Introduction: Spider bites are a reality of living in the Midwest. It is important to differentiate between those with bites, and other disease processes. In this abstract, we will follow a patient diagnosed with a brown recluse bite and learn how to differentiate between a bite and another disease process.   Methods: Bites are presented initially as an area that is open or closed, often with a dusky hue. These lesions will evolve over the next few days. 1% of these will cause hemolytic anemia, angioedema, and death.  Utilizing the mnemonic “NOT RECLUSE” may assist providers with differentiation between a true bite and another diagnosis- numerous, occurrence, timing, red center, elevated, chronic, large, ulcerates too early, swollen, exudative.  This mnemonic is useful; however, it is not always a steadfast companion in some cases.  This is a study following a 69-year-old gentleman bitten by a brown recluse, in Oklahoma.  ER-3/7/23- ER where he noticed a quarter sized area on his thigh that was tender to touch.    3/23- Patient presents to PCP. Loxoscelism present. cephalexin 500mg TID x 5d. Silvadene to bite.   3/17- Initial wound care visit. collagenase, and sharp debridement. L: 3.80 cm x W: 4.50 cm x D: 0.1 cm x area: 17.10 cm   5/8- Gentian violet and methylene blue dressing.   6/16- Gentian violet and methylene blue dressing, epibole resolved.   7/14- healed. L: 0.00 cm x W: 0.00 cm x D: 0 cm x area: 0.00 cm  Results:Patient managed using collagenase, gentian violet and methylene blue dressing, and sharp debridement. Total healing in roughly 4 months. Significant decrease in scarring noted at 6 months.  Discussion: Bites are typically more uncommon than believed to be. Approximately 10-20% of bites become necrotic. Recluse spiders will usually bite as a last defense, usually when crushed or rolled over on. The mnemonic NOT RECLUSE can assist with differentiation. Patients can only be definitively diagnosed with a spider bite if they have a consistent skin lesion AS WELL AS either a spider being observed, or the spider was collected. If both are not met, then other diagnoses such as vasculitis, pyoderma, infection must be ruled out.  There are several different approaches that can be used when evaluating and treating a spider bite.  References:Goddard, J. & Stewart, P. (2023). Insect and other arthropod bites. UpToDate. Insect and other arthropod bites - UpToDate Vetter, R. & Swanson, D. (2024). Bites of recluse spiders. UpToDate. Bites of recluse spiders - UpToDate Vetter, R. & Swanson, D. (2023). Diagnostic approach to the patient with a suspected spider bite: An overview. UpToDate. Diagnostic approach to the patient with a suspected spider bite: An overview - UpToDate