Serum SicknessSymptoms, Doctors, Treatments, Advances & More
Learn About Serum Sickness
Serum sickness is a reaction that is similar to an allergy. The immune system reacts to medicines that contain proteins used to treat immune conditions. It can also react to antiserum, the liquid part of blood that contains antibodies given to a person to help protect them against germs or poisonous substances.
Drug allergy - serum sickness; Allergic reaction - serum sickness; Allergy - serum sickness
Plasma is the clear fluid portion of blood. It does not contain blood cells. But it does contain many proteins, including antibodies, which are formed as part of the immune response to protect against infection.
Antiserum is produced from the plasma of a person or animal that has immunity against an infection or poisonous substance. Antiserum may be used to protect a person who has been exposed to a germ or toxin. For example, you may receive a certain type of antiserum injection:
- If you have been exposed to tetanus or rabies and have never been vaccinated against these germs. This is called passive immunization.
- If you have been bitten by a snake that produces a dangerous toxin.
During serum sickness, the immune system falsely identifies a protein in antiserum as a harmful substance (antigen). The result is an immune system response that attacks the antiserum. Immune system elements and the antiserum combine to form immune complexes, which cause the symptoms of serum sickness.
Certain medicines (such as penicillin, cefaclor, and sulfa medicines) can cause a similar reaction.
Injected proteins such as antithymocyte globulin (used to treat organ transplant rejection) and rituximab (used to treat immune disorders and cancers) can cause serum sickness reactions.
Blood products may also cause serum sickness.
Unlike other medicine allergies, which occur very soon after receiving the medicine, serum sickness develops 7 to 21 days after the first exposure to a medicine. Some people develop symptoms in 1 to 3 days if they have already been exposed to the medicine.
Symptoms of serum sickness can include:
- Fever
- General ill feeling
- Hives
- Itching
- Joint pain and swelling
- Rash
- Swollen lymph nodes
Medicines, such as corticosteroids, applied to the skin may relieve discomfort from itching and a rash.
Antihistamines may help ease a rash and itching.
Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen or naproxen, may relieve joint pain. Corticosteroids taken by mouth may be prescribed for severe cases.
The medicine that caused the problem should be stopped. Avoid using that medicine or antiserum in the future.
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Marie Scully practices practicing medicine in London, United Kingdom. Ms. Scully is rated as an Elite expert by MediFind in the treatment of Serum Sickness. She is also highly rated in 16 other conditions, according to our data. Her clinical expertise encompasses Purpura, Thrombocytopenia, Blood Clots, Adult Immune Thrombocytopenia, and Splenectomy.
The Allergy, Asthma & Sinus Center
. Dr. Jones is rated as an Advanced provider by MediFind in the treatment of Serum Sickness. He is also highly rated in 22 other conditions, according to our data. His clinical expertise encompasses Ozena, Nonallergic Rhinopathy, Empyema, and Sinusitis. Dr. Jones is board certified in American Board Of Allergy And Immunology and American Board Of Internal Medicine.
OSF Medical Group - Allergy & Immunology
Sylwia Nowak is a Pediatrics specialist and an Allergy and Immunologist practicing medicine in Peoria, Illinois. She has been practicing medicine for over 10 years. Dr. Nowak is rated as an Experienced provider by MediFind in the treatment of Serum Sickness. Her clinical expertise encompasses Ozena, Nonallergic Rhinopathy, Childhood Iron Deficiency Anemia, and Allergic Rhinitis. Dr. Nowak is board certified in American Board Of Allergy And Immunology and American Board Of Pediatrics.
The symptoms usually go away within a few days once the underlying cause is removed.
If you use the medicine or antiserum that caused serum sickness again in the future, your risk of having another similar reaction is high.
Complications include:
- Inflammation of the blood vessels
- Swelling of the face, arms, and legs (angioedema)
Contact your provider if you received medicine or antiserum in the last 4 weeks and have symptoms of serum sickness.
There is no known way to prevent the development of serum sickness.
People who have had serum sickness or medicine allergy should avoid future use of the antiserum or medicine that caused the reaction.
Published Date: January 20, 2026
Published By: Deborah Pedersen, MD, MS, Allergy & Asthma Care, PC, Taunton, MA. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
Frank MM, Hester CG. Immune complexes and allergic disease. In: Burks AW, Holgate ST, O'Hehir RE, et al, eds. Middleton's Allergy: Principles and Practice. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 37.
Nadeau KC. Approach to the patient with allergic or immunologic disease. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 230.
Nowak-Wegrzyn A, Sicherer SH. Serum sickness. In: Kliegman RM, St. Geme JW, Blum NJ, et al, eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia, PA: Elsevier; 2025:chap 191.