Allergic Reaction To Limes

Fresh lime juice adds tang to cocktails, salad dressings, marinades and Key lime pie. In the 18th century, the British Navy included vitamin C-loaded fresh limes in its ship stores as scurvy preventatives. However, these tart, refreshing citrus fruits also contain two common allergens. Ingesting, or simply touching, fresh limes or lime juice can result in an allergic reaction.

Psoralens

Limes and other citrus fruits contain psoralens, compounds of the furocoumarin family. Also found in celery, furocoumarins are photosensitizing substances. Skin exposed first psoralens and then to direct sun may develop phytophotodermatitis. This allergic reaction resembles severe sunburn. A case report in the March-April 2002 "Canadian Journal of Infectious Diseases," discussed the case of a patient at McGill University's SMBD-Jewish General Hospital in Montreal. The patient used lime juice as a hair lightener before spending several hours in direct sun. Her exposed skin later developed a red rash. Symptoms of severe lime-induced phytophotodermatitis include nausea, vomiting and fever. The condition develops two to three days following exposure and lasts as long as two weeks, notes the case study's author, Christina Greenaway, M.D.

Profilins

Limes also contain proteins called profilins. Profilins help protect plants from infections and soil- or climate-related stresses. They also trigger approximately one-third of pollen allergies and many fruit and vegetable allergies, according to the Sydney Children's Hospital website. Approximately 3 percent of teenagers have an allergic reaction to lime profilins, notes the Hospital. A reaction to profilin exposure typically includes oral allergy syndrome, mouth- and tongue-related swelling, and itching shortly after contact. Heating lime juice reduces prolifins' effects, but it simultaneously destroys vitamin C.

Lime Food Allergy Mechanism

The allergic reaction to consuming limes or lime juice results from an immune system response to lime proteins. The immune system identifies the proteins as dangerous substances. It releases the Immunoglobulin E antibody to fight them. In turn, IgE signals mast cell histamine production, causing inflammation and other allergy symptoms. In very sensitive people, ingesting lime proteins may lead to anaphylaxis, a life-threatening condition.

Symptoms

Lime allergy produces symptoms similar to those of other food allergies. In addition to oral allergy syndrome, these reactions may include nausea, vomiting, gas and other digestive distress. Respiratory involvement includes wheezing, nasal congestion or discharge, watery eyes and breathing difficulty. Hives, rashes or eczema affect the skin. Symptoms arise shortly after consumption, much sooner than those of phytophotodermatitis.

Considerations

Teens and young adults have higher incidences of lime allergy than young children. This allergy typically continues through their adult lives. Red and green peppers, broccoli and strawberries are alternative vitamin C sources for people allergic to limes and other citrus.