Symptoms that occur after an insect bite or sting are caused by the
injection of venom or other substances into your skin. With minor bites, the
reaction covers a small area. A bump rises on your skin at the site of the
bite, the area may itch for a few hours, and the skin irritation and discomfort
will go away over a few days. It is not uncommon for swelling from a bite or
sting around a hand or foot to be worse during the second 24-hour period. Home
treatment is often all that is needed.
A more serious reaction will cause redness and swelling beyond the
bite site. A major reaction is defined as redness and swelling across two major
joints, such as from below the ankle to above the knee or from below the elbow
to above the shoulder. Moderate to severe swelling requires a visit to a health
professional and often a prescription medication to reduce the swelling.
An allergic reaction can cause swelling elsewhere in the body besides
the bite or sting site, especially on the face, tongue, throat, hands, and feet
(angioedema). An allergic reaction requires emergency
care.
It is often hard to tell the difference between an allergic reaction
and signs of early infection. Both may cause redness and swelling. An infection
often causes tenderness at the site of the infection. The redness and swelling
of an infection often spreads and tends to move toward the body, following the
lymph nodes. An allergic reaction often causes more itching than
tenderness.
