Clinical and laboratory characteristics of hospitalized patients with spider bites in Hangzhou, Southeast China

Introduction Spider bites are relatively common arthropod injuries in China, but systematic clinical investigations remain limited. This study aims to describe the clinical manifestations and laboratory profiles of hospitalized patients with a definite history of spider exposure in Hangzhou, southeast China.Methods We retrospectively reviewed the medical records of 60 hospitalized patients with a definite history of spider exposure. Demographic information, clinical presentations, laboratory findings, and in-hospital management data were collected for descriptive analysis.Results A total of 60 patients were included, with a median age of 50 years (IQR 39.8–64.5 years). Females accounted for 36 cases (60%) and males for 24 (40%). The bites occurred mainly on the lower limbs (46.7%) and upper limbs (30%), followed by the trunk (15%) and the head and neck (8.3%). Most bites occurred between May and August. Pain and erythema were observed in all patients, followed by swelling (98.3%), induration (66.7%), necrosis (60%), and itching (50%). Bruising occurred in nine patients (15.0%), lymphangitis in eight (13.3%). Laboratory tests revealed elevated inflammatory markers, with C-reactive protein concentration greater than 10 mg/L in 20% and white blood cell count greater than 9.5 × 109/L in 78.3%. Mild elevations were also noted in alanine aminotransferase activity (18.3%), aspartate aminotransferase activity (13.3%), gamma-glutamyl transpeptidase activity (28.3%), and lactate dehydrogenase activity (13.3%), while coagulation and renal parameters remained largely normal. The median hospital stay was seven days (interquartile range 5–8 days). All patients received structured inpatient wound management and medical therapy, with surgical wound interventions required in five cases (8.3%).Discussion The clinical presentation was predominantly localized, consistent with previous findings on non-lethal spider bites. Seasonal clustering from May to August reflected increased spider activity and human exposure during warmer months. Most cases were characterized by localized manifestations without severe systemic toxicity, although structured wound management remained essential.Conclusion Spider bites in Hangzhou were mainly localized with minimal systemic effects. Raising public awareness and strengthening prevention during high-incidence months may help reduce cases.