A large skin reaction involves swelling and redness that spreads away from the site of the bite or sting. It may involve an entire limb or a broad area of the body. A large skin reaction is defined as swelling across two major joints, such as from the elbow to the shoulder.

Signs of a large skin reaction include the following:

• The reaction is usually at its worst after 48 hours.
• The reaction may last as long as 7 days.
• Fatigue and nausea may be present.