This infected area can enlarge to the size of a silver dollar. It will become ulcerated and sunken. In rare instances, the reaction could become systemic after 12 hours. A systemic reaction is characterized by fever, nausea, and vomiting. Children are most prone to systemic reactions.
First aid is generally the same as with black widow bites.
The person who was bitten should be taken to a medical care facility as soon as possible. If the spider can be found, it should be collected and taken with the patient to the doctor. Doctors may prescribe corticosteroids, such as prednizone, along with antibiotics to prevent bacterial infections in the lesion. Lesions may take months to heal. Control of the brown recluse spider is critical.