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Managing Cancer Care

What are Infusion or Immune Reactions?

Infusion reactions can happen when your body has a strong immune response to a cancer treatment that's given intravenously (IV). The types of drugs used in these cancer treatments can be chemotherapy, targeted therapy, or immunotherapy. The process of giving the treatment might be called an IV infusion, injection, or push.

Most treatments have a low risk for infusion reactions, but for some the risk is higher. And, sometimes the severity of a reaction depends on the dose of the drug and other factors that may be related to the treatment or to other health problems a patient may have. If an infusion reaction happens, it's because your body is reacting very strongly to the treatment which is a foreign substance. Your immune system responds because it's trying to fight off the foreign substance, causing the reaction.

You may hear your cancer care team call these immune reactions or hypersensitivity reactions. Infusion reactions are not true allergic reactions because of how they start in the immune system. But, they can be severe in some people if not recognized and treated quickly. Infusion reactions can happen when the patient is getting that infusion for the first time or at any time during the treatment period, even if the patient has received the infusion once or more times before.

Infusion reactions can be immediate or delayed. Immediate reactions happen within minutes of beginning to receive your infusion. Delayed reactions can happen up to a few days or weeks after receiving your infusion. Infusion reactions can be mild, moderate, or severe.

If an infusion is in your treatment plan, talk to your cancer care team about what you'll be getting, your risk of having an infusion reaction, and what to expect if it happens.

What to watch for during any treatment infusion

  • Itching
  • Rash or hives
  • Swelling of the tongue, lips, or eyelids
  • Redness on the face and neck area, also called flushing
  • Fever or chills
  • Cough
  • Nausea
  • Muscle or joint pain
  • Edema (swelling of any part of your body, but more common in hands, legs, ankles, and feet)
  • Feeling short of breath

If you have any of these symptoms during your infusion, let your infusion nurse know right away. If you have any of these symptoms at home after your infusion, call your cancer team right away.

Reactions or side effects specific to immunotherapy

When receiving immunotherapy, you may have any of the reactions listed above. However, most reactions to immunotherapy don't usually occur during the infusion. Talk to your cancer care team about what to expect and call them or let them know if you have one or more of the following symptoms, as it could mean you are reacting to the immunotherapy drug.

  • Skin rash or blisters, which could be mild or severe.
  • Colitis (inflammation of the colon) that could cause pain, diarrhea, fever, joint pain, and loss of appetite.
  • Hepatitis (inflammation of the liver). Let your doctor know if you notice your skin or the whites of your eyes are yellowish, or if you have nausea and vomiting, pain on the right side of the abdomen, feeling drowsy, urine that is dark (tea-colored), loss of appetite, and bruising or bleeding more easily than usual.
  • Pneumonitis (inflammation of the lung). Let your doctor know if you have fever, shortness of breath or difficulty breathing, chest pain or cough.
  • Changes to how your endocrine (hormone) system works. The endocrine system is responsible for making and produce hormones for different jobs in your body. Let your doctor know if you notice one or more of the following, as it could mean your endocrine system is not working as it should:
    • Changes in your eyesight
    • Headaches that don’t go away
    • Weakness or fatigue that is more than normal
    • Increased heart rate (your heart beats faster than normal)
    • Muscle or joint aches or pain
    • Dizziness or fainting
    • Feeling more hungry than usual
    • Urinating more than usual
    • Changes in mood
    • Feeling cold
    • Voice getting deeper
    • Nausea or vomiting
    • Pain in your belly
    • Constipation
  • Mouth problems such as stomatitis (inflammation of the mouth and lips) and mucositis (inflammation of the digestive lining). Let your doctor know if you notice soreness, blisters, or ulcers in your mouth or lips. If you have mouth sores: Practice good oral hygiene; brush your teeth two or three times daily with a soft toothbrush, and floss; use alcohol-free toothpastes and rinses. Avoid spicy, hard, acidic, and hot foods. Avoid alcohol and tobacco products. Your doctor may be able to prescribe a mouth rinse to help with the pain and irritation.\
  • Arthritis (inflammation of the joints, such as ankles, knees, or hands). Let your doctor know if you notice swelling in your joints, pain, rash around your joints, or feeling stiff after you’ve been inactive for a while such as in the morning.
  • Muscle pain and/or weakness
  • Peripheral neuropathy (numbness and tingling in extremities). Let your doctor know if you have numbness or tingling in your hands or feet, numbness, weakness, less ability to feel hot and cold, or cramps in your feet.
  • Nephritis (inflammation of the kidney). Your doctor is usually able to tell how well your kidney works by doing lab tests throughout your treatment time. Your doctor will eliminate all other causes (not drinking enough water or other health conditions) before confirming that you have nephritis.
  • Frequent headaches, light sensitivity, neck stiffness, confusion, or short-term memory loss. Let your doctor know if you experience any of these symptoms
  • Let your doctor know if you notice chest pain, irregular heartbeat, swelling of your hands and feet, difficulty breathing and feeling very tired.
  • Changes in your hearing or eyesight. Changes in your eyesight may include blurred vision, light sensitivity, pain with eye movement, or swelling in your eyelids.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Brahmer JR, Lacchetti C, Schneider BJ, et al. Management of immune-related adverse events in patients treated with immune checkpoint inhibitor therapy: American Society of Clinical Oncology clinical practice guideline. Journal of Clinical Oncology. 2018; 36(17):1714-1768.

Bonamichi-Santos R, Castells M. Diagnoses and management of drug hypersensitivity and anaphylaxis in cancer and chronic inflammatory diseases: Reactions to taxanes and monoclonal antibodies. Clinic Rev Allerg Immunol. 2018; 54:375-385.

Kroschinsky F, Stölzel F, Bonin S, et al. New drugs, new toxicities: severe side effects of modern targeted and immunotherapy of cancer and their management. Critical Care. 2017; 21: 89.

National Comprehensive Cancer Network (NCCN). Management of immunotherapy-related toxicities. 2019. Version 2.2019. Accessed at on September 20, 2019. 

Vigarios E, Epstein JB, Sibaud V. Oral mucosal changes induced by anticancer targeted therapies and immune checkpoint inhibitors. Support Care Cancer. 2017; 25:1713-1739


Last Revised: February 1, 2020

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