Woman Developed a Temporary Peanut Allergy After a Lung Transplant

Patient: A 47-year-old woman living in Canada

Symptoms: The woman underwent a lung transplant to treat interstitial lung disease, a condition that can cause inflammation and scarring in lung tissue.

While recovering in the hospital, she ate a bowl of breakfast cereal and soon developed flushing, itching, shortness of breath and dangerously low blood pressure. The symptoms lasted for nearly two hours.

A severe allergic reaction after eating cereal

This potentially life-threatening reaction was consistent with anaphylaxis, a rapid and severe allergic response that can affect breathing and blood pressure. The case report did not specify the exact treatment she received, but the reaction resolved after about two hours.

Standard treatment for anaphylaxis typically involves an immediate injection of epinephrine. Depending on the symptoms, doctors may also use antihistamines, corticosteroids, oxygen or inhaled medicines such as albuterol.

Allergic reactions continued after discharge

What happened next: For several weeks after leaving the hospital, the woman experienced similar symptoms after eating coconut cream pie and an almond candy bar.

Although these foods contained nuts, none were known to contain peanuts. They also were not certified as peanut-free, meaning that accidental contamination could not be ruled out.

Allergy testing revealed peanut and pine nut sensitivity

Diagnosis: Two months after her lung transplant, the woman underwent skin-prick allergy testing. The test showed sensitivity to peanut and pine nut allergens. However, she did not test positive for allergies to almonds or coconut.

The woman’s doctors noted that her lung donor was a 12-year-old boy with a known peanut allergy, although he had never experienced anaphylaxis. They proposed that immune cells within the donated lung tissue may have been sensitized to peanut allergens and transferred the allergy to the recipient.

How can an organ transplant transfer an allergy?

Organ transplants can rarely transfer immune sensitivities from donors to recipients. This phenomenon is known as a donor-acquired allergy.

Lungs and livers may be more commonly associated with donor-acquired allergies than some other transplanted organs because they contain immune cells, including B lymphocytes. These cells can produce antibodies that recognize specific allergens.

Other immune cells, including mast cells and basophils, can also contribute to allergic reactions. When these cells encounter an allergen, they may release inflammatory chemicals that cause symptoms such as itching, flushing, breathing difficulties and low blood pressure.

The peanut allergy eventually disappeared

Treatment and outcome: The woman did not require a specific long-term treatment to eliminate the new allergy. Her sensitivity decreased during follow-up testing and had completely disappeared within one year of the transplant.

A few months after surgery, she ate peanuts in a supervised medical setting and did not experience an allergic reaction. Her doctors theorized that the donor’s sensitized immune cells had gradually been removed or replaced within her body.

A blood test for peanut-specific antibodies was negative, suggesting that her body was not continuously producing those antibodies. This finding raised the possibility that the reaction was caused by antibodies attached to mast cells or basophils in the transplanted tissue rather than by newly produced antibodies from circulating lymphocytes.

However, the woman’s positive skin-prick test suggested that lymphocytes could still have played a role. The precise immune mechanism behind her temporary peanut allergy remained uncertain.

A rare complication of lung transplantation

What makes this case unusual: Only one other case of a peanut allergy developing after a lung transplant had been reported before this woman’s case was published in 2011.

Scientists began recognizing the potential for organ donors to pass allergies to recipients only relatively recently. Donor-acquired allergies have also been reported after bone marrow transplants, which directly involve the immune system.

The first known donor-acquired allergy involving a solid organ transplant was reported in 1997 after a combined kidney and liver transplant from a peanut-allergic donor.

A 2025 review of donor-acquired allergies found that these reactions appear to occur more often after lung and liver transplants than after other solid-organ transplants. The authors suggested that the high concentration of immune cells in these organs could help explain the pattern.

Why donor allergy histories matter

Although the woman’s allergy faded after about a year, the case highlights the importance of documenting donor allergies and monitoring transplant recipients for unexpected reactions.

The doctors who reported the case recommended that transplant teams obtain detailed allergy histories from donors whenever possible. Skin-prick testing and other allergy evaluations may also help identify donor-acquired allergies after transplantation.

People who develop symptoms such as difficulty breathing, swelling, widespread itching, dizziness or low blood pressure after eating should seek emergency medical care immediately. These symptoms may indicate anaphylaxis.

This article is for informational purposes only and does not provide medical advice.

Source: Binder, S., Heffer, M. J., Lee, J. K., Chaparro, C. and Tarlo, S. M. (2011). “Development of transient peanut allergy after lung transplantation: a case report.” Canadian Respiratory Journal, 18(3).