When to Seek Immediate Medical Care: Severe symptoms: If the bite area is rapidly worsening, developing a blister or ulcer, or turning black (necrosis). Systemic symptoms: If you experience nausea, vomiting, fever, body aches, or difficulty breathing. Signs of infection: If the bite area becomes increasingly painful, red, swollen, or starts draining pus. Suspected complications: If you develop signs of a systemic reaction like jaundice, kidney failure, or seizures.