Cold sores are painful, fluid-filled blisters and itchy open sores caused by the herpes simplex virus. The National Institute of Dental and Craniofacial Research estimates that between 40 and 80 percent of Americans are infected with the virus. Some people experience no symptoms at all, while the remainder -- between 20 and 40 percent -- suffer recurrent bouts of cold sores. For some people, unrecognized food allergies can trigger a bout of cold sores. A doctor can perform tests that confirm the diagnosis.
Definition
Food allergies represent an abnormal response of the immune system to substances in foods. When the affected person consumes the allergenic food, the immune system releases antibodies, just as it would in response to bacteria or viruses. Fortunately, food allergies are uncommon. The National Institute of Allergy and Infectious Diseases, or NIAID, estimates that food allergies affect just 4 percent of adults and 6 to 8 percent of children.
Significance
The common link between cold sores and food allergies is the immune system. When a person with a food allergy consumes the allergenic food, the immune system becomes distracted because it is "fighting" the allergenic food. This allows the herpes simplex virus to multiply unchecked, resulting in cold sores. In some cases, contact with allergenic substances present as food contaminants may be enough to trigger outbreaks. For example, in the July/September issue of the "Journal of Biological Regulators and Homeostatic Agents," a team of Italian researchers led by Edoardo Rosato, Ph.D., found that people with nickel allergies experienced more frequent cold sore outbreaks than their non-nickel allergic counterparts, at least until they consumed a special, low-nickel diet.
Diagnosis
People who experience cold sore outbreaks in response to eating common food allergens -- such as shellfish, salmon, nuts, eggs, milk, soy and wheat -- should ask their doctors about tests for food allergies. For people who are allergic to ragweed, cantaloupe can produce food allergies during ragweed season. Similarly, birch pollen allergies can cause an allergic reaction to apple peels through a process that NIAID calls "cross-reactivity." Unfortunately, food allergens are often culture specific. For example, rice is a common food allergy among Japanese people, while Scandinavian people often develop allergies to codfish.
Management
Management of cold sores related to food allergies focuses on avoiding the allergenic food. The Food and Drug Administration requires manufacturers to disclose the ingredients of processed foods on the labels. Restaurant patrons should read menus carefully and ask questions about ingredients and food handling. Food allergies can also provoke life-threatening symptoms such as anaphylaxis that are far more serious than cold sores. A doctor may recommend that the affected person wear an identification bracelet or carry prescription medications, such as epinephrine injection device.
Considerations
Cold sores are often provoked by triggers other than food allergies, including fatigue, stress, illness, poor diet, sunburns or excessive sunlight exposure, dental work or mouth injuries caused by wires or braces or accidental mouth bites. While some of these triggers are unavoidable -- such as illness or dental work -- others --such as poor diet, excessive sun exposure and loose braces wires -- are not. People who experience severe, frequent or long-lasting -- longer that two weeks -- cold sore outbreaks should see a doctor, regardless of whether they suspect food allergies.
References
- National Institute of Dental and Craniofacial Research: Fever Blisters and Canker Sores
- National Institute of Dental and Craniofacial Research: Oral Health in America--A Report of the Surgeon General
- "Journal of Biological Regulators and Homeostatic Agents"; Recurrent Infections in Patients with Nickel Allergic Hypersensitivity; Edoardo Rosato, Ph.D. et al.; July-September 2009
- "Integrative Medicine"; David Rakel, M.D.; 2007
- National Institute of Allergy and Infectious Diseases: Food Allergy: What Is Food Allergy?
- National Institute of Allergy and Infectious Disease: Food Allergy: Treatment
