Some people have an allergic reaction to chemotherapy. Allergic reactions can range from mild skin irritation to life threatening anaphylaxis. To avoid this, your care team will monitor you during and after chemotherapy administration.
Chemotherapy is one of the most common cancer treatments, and it plays an essential role in destroying cancer cells. Although it can be lifesaving, it usually damages healthy cells and causes some side effects.
All medications, including chemotherapy drugs, have the potential to trigger allergic reactions. An allergic reaction occurs when your immune system sees the medication as threatening and overreacts.
The most severe type of allergic reaction is called anaphylaxis, which can cause throat swelling and potentially life threatening breathing problems. It often develops within minutes of treatment or many cycles into the treatment.
Keep reading to learn more about allergic reactions to chemotherapy.
An allergy to chemotherapy medications can cause symptoms that can range from mild to life threatening. About
Allergy signs and symptoms
Potential signs and symptoms of a chemotherapy allergy can include:
- head and neck symptoms, such as:
- swelling around your eyes
- nasal itching
- nasal congestion
- itching, tingling, or swelling in the lips, tongue, or mouth
- a metallic taste in your mouth
- hoarseness
- trouble swallowing
- respiratory symptoms, such as:
- cardiovascular and torso symptoms, such as:
- fainting and faintness
- dizziness
- heart palpitations
- gastrointestinal symptoms, such as:
- gynecological and urinary symptoms, such as:
- vaginal itching
- uterus cramps
- bleeding
- incontinence
- neurological symptoms, such as:
Chemotherapy and anaphylaxis
Chemotherapy is the
In a 2021 study from Japan, researchers investigated the lifetime incidence of severe anaphylaxis in people who received at least one dose of chemotherapy into a vein. Of the 5,584 people in the study,
The three drugs that caused severe anaphylaxis most often were:
| Medication | Number of people it affected | Percentage of people it affected |
|---|---|---|
| carboplatin | 14 out of 1,037 | 1.4% |
| paclitaxel | 9 out of 1,034 | 0.87% |
| trastuzumab | 1 out of 166 | 0.60% |
The researchers reported the highest risk situations as repeated carboplatin administration and the first few administrations of paclitaxel.
The incidence of severe anaphylaxis among people who received 10 doses of carboplatin was as high as 8.1%. Severe anaphylaxis resulting from paclitaxel generally occurred within the first 5 minutes of the first dose.
Allergic reactions generally start within
Doctors give most chemotherapy medications intravenously through your bloodstream, and these reach many tissues rapidly. Some medications are oral or topical, and your body generally takes longer to absorb these medications.
Allergic reactions due to topical medications, which you apply to your skin, can sometimes be delayed by a few days.
In the 2021 study from Japan, all cases of severe anaphylaxis occurred between
Chemotherapy medications target cells that replicate quickly, such as cancer cells. However, they can incidentally damage many healthy cells in your body, such as:
- skin cells
- gastrointestinal cells
- hair cells
- blood cells
Many side effects of chemotherapy result from damage to these cells. Some of the most common
- fatigue
- nausea and vomiting
- diarrhea or constipation
- easy bruising and bleeding
- hair loss
- loss of appetite
- frequent infections
- sores around your mouth, tongue, or throat
- low red blood cell count
- numbness, tingling, or pain in your limbs (peripheral neuropathy)
- dry skin or brittle nails
- kidney and bladder problems
- unintentional weight loss
- brain fog
- mood changes
- low sex drive
- fertility problems
Many different chemotherapy drugs are available to help treat cancer. If you react to one of the medications or a combination of medications, your doctor might recommend switching to a different chemotherapy regimen.
Depending on the type of cancer you have, your doctor might also recommend alternative treatments, such as:
The best alternative treatment plan largely depends on factors such as:
- your type and subtype of cancer
- the extent of your cancer
- your overall health
- your age
Finding support
Getting cancer treatment can be incredibly stressful. Many people find joining support groups or talking with a healthcare expert helpful.
Here are some resources you might find useful:
- the
American Cancer Society’s 24/7 cancer helpline at 800-227-2345 - the Cancer Survivors Network for cancer patients, survivors, caregivers, families, and friends
- CancerCare support groups
- the Cancer Support Community
- the
National Cancer Institute’s support directory
The following are answers to some frequently asked questions about allergic reactions to chemotherapy.
How long after chemo can you have an allergic reaction?
After chemotherapy, an allergic reaction could occur within
How common is an allergic reaction to chemo?
An allergic reaction to chemotherapy is uncommon. About 5% of those receiving treatment experience a reaction.
What is the protocol for anaphylaxis from chemotherapy?
If anaphylaxis from chemotherapy occurs while you’re still in the cancer center or at the hospital, the protocol involves immediately taking the drug epinephrine. If it occurs while you’re at home, you or someone else should call 911 or seek medical support immediately.
Chemotherapy can cause allergic reactions that range from mild to life threatening. Severe anaphylactic reactions usually occur within minutes of chemotherapy administration.
If you have an allergic reaction to chemotherapy, your cancer team might recommend switching medications or receiving a different type of cancer treatment. Alternative options include immunotherapy, targeted therapy, and surgery.