Serum sickness is a type of delayed allergic response, appearing four to 10 days after exposure to some antibiotics or antiserum, the portion of serum that contains antibodies, such as gamma globulin.

The first step in treatment of serum sickness is always to discontinue the drug or other substance which is suspected of causing the reaction. After that, all treatment is symptomatic. Antihistamines, pain relievers, and corticosteroids may be given.

While other types of allergic reactions may produce a rapid response, the serum sickness reaction is delayed because it takes time for the body to produce antibodies to the new protein.

No. Even though the treatment solution for allergy shot is sometimes called "allergy serum", there is no serum in these solutions. Serum sickness occurs when a large dose of an animal serum protein or a large dose of some medications are given and the immune system make high doses of immune antibody against that protein. Small capillaries in the joints, kidneys, skin, etc get plugged up by the clumps formed when the antibody joins with the protein. Allergy shots use very week doses because the person is already allergic to the treatment solution. Large doses are required to develop serum sickness.

Most serum sickness reactions are mild, and disappear on their own after one or two weeks as long as the cause is removed. Sometimes, symptoms.may continue for several weeks. In very rare cases.there can be severe reactions and permanent damage.