Peanut allergy is a common food allergy that can cause serious reactions in affected individuals. It occurs when the immune system mistakenly identifies proteins in peanuts as harmful substances, triggering an allergic response. While often associated with childhood, there is growing recognition that these allergies can emerge at any point in life, including adulthood.
Adult-Onset Peanut Allergy is Possible
Peanut allergies can develop later in life, including adulthood. While food allergies are most common in children, many adults experience their first peanut allergy symptoms after reaching adulthood. Approximately 17% of adults with peanut allergies, or over 800,000 U.S. adults, reported developing the allergy after age 18.
This phenomenon, known as adult-onset peanut allergy, means that an individual who previously consumed peanuts without issue can suddenly become allergic. Despite its occurrence in older individuals, peanut allergy is still often considered primarily a pediatric concern. However, studies indicate that the prevalence of peanut allergy among U.S. adults is substantial, affecting around 4.5 to 4.6 million individuals.
Factors Contributing to Later Development
The exact reasons why some individuals develop peanut allergies later in life are not fully understood, but several factors are believed to play a role. Genetic predispositions can increase the risk, especially if there is a family history of food or environmental allergies. Studies suggest a link between peanut allergies and specific gene regions.
Environmental factors may also contribute to the late onset of peanut allergy. Moving to a new geographic location can expose an individual to different allergens, potentially triggering new sensitivities. Changes in the immune system as people age can also make them more susceptible to developing new allergies.
Research is exploring the role of gut microbiota; a 2023 study suggested changes in gut bacteria may influence peanut allergy development. Previous sensitization to peanuts without overt symptoms, or cross-reactivity with other allergens like tree nuts or pollen, might also contribute to a delayed manifestation of the allergy. Some allergies might have been present in childhood but went unrecognized or undiagnosed due to limited exposure to the allergen.
Recognizing and Managing New Symptoms
If someone suspects they have developed a peanut allergy later in life, recognizing the symptoms is the first step. Allergic reactions typically occur within minutes of exposure to peanuts, though they can sometimes be delayed up to two hours. Common symptoms include skin reactions such as hives, redness, swelling, or itching. Digestive issues like stomach cramps, nausea, vomiting, or diarrhea may also occur.
Respiratory symptoms can manifest as wheezing, shortness of breath, or a repetitive cough, while itching or tingling in the mouth and throat are also frequently reported. In severe cases, a reaction can progress to anaphylaxis, a life-threatening response that may involve:
Impaired breathing
Swelling in the throat
A sudden drop in blood pressure
Dizziness
Loss of consciousness
If these symptoms appear after consuming peanuts, seek medical attention immediately. A healthcare professional, such as an allergist, can conduct tests like skin prick tests or blood tests to confirm a peanut allergy diagnosis. Management strategies involve strict avoidance of peanuts and peanut-containing products. Individuals diagnosed with a peanut allergy are advised to carry an epinephrine auto-injector, a device that delivers a dose of epinephrine to counteract severe allergic reactions, as this medication is the first-line treatment for anaphylaxis.