BP and CSF pressure are usually elevated in more severe cases in adults. Brown or violin spider bites may cause an immediate burning sensation or little or no immediate pain, although some localized pain develops within 30 to 60 min. The bite area becomes erythematous and ecchymotic and may itch. Generalized pruritus may also be present. Pain can be severe and involve the entire injured area.
Fatal cases are rare.
Every attempt should be made to capture and identify the offending spider. Widow spiders are identified by a red or orange hourglass marking on the ventral abdomen. Brown or violin spiders have a violin-like marking on the cephalothorax. If the patient cannot confirm a spider bite, alternative diagnoses should be considered. Some arthropod bites may give rise to bullous lesions that rupture and ulcerate, resembling those of violin and certain other spiders.