September 28, 2020
When we listen to the word latex for the first time, our mind links two more words with it: white and rubber. Latex is naturally found as a liquid emulsion in certain species of flowering plants. It constitutes a variety of proteins, sugars, oils, resins, alkaloids, etc that gives it a remarkable stability. This version of latex has been immensely useful in the manufacture of various substances. This is because of its combination of strength, flexibility and compressibility. Moreover, its resistance to wear and tear and high tolerance to heat makes it a desirable raw material.
Natural rubber latex (NRL) is used in the manufacturing of rubber bands, gloves, adhesives, springs, bearings, etc. Despite its versatility, NRL can be harmful to some humans. It can be a source of an allergic reaction that is known as hypersensitivity. Hypersensitivity occurs when the body reacts severely to an allergen. This same allergen might be completely harmless agent for most people. These reactions have a cascading detrimental effect on the respiratory system, immune system and the skin.
An allergy to NRL can get worse when it is coupled with another allergy caused by a common type of food source - fruits. The relation between an allergy due to natural rubber latexand a particular fruit began to attract attention in the mid-1990s. It was later when researchers found out an association between the two, concluding that a cross-reaction occurs because of the two different allergens and that leads to multiple symptoms associated with different organ systems. This was thus given the name Latex-Fruit Syndrome (LFS).
LFS, if present in an individual, can pose a major challenge to get diagnosed. This is because there is no definitive test to confirm its diagnosis. It is rather a chain of multiple tests that mainly work on the principle of eliminating all the possible options one by one. These tests include the following:
Clinical History - The patient is asked if at all he or she has had any past experiences where they suffered from a hypersensitivity reaction in response to a particular fruit.
Oral Challenge Test - The patient is made to eat different varieties of fruits in increasing quantity that can help in establishing that at what quantity the allergic reaction occurs.
Skin Prick Test - This is also known as a prick by prick test. In this, a prick on the skin can help in determining if an individual is suffering from a particular type of allergy by testing it against 50 different substances. In adults, the prick is made on the forearm, whereas it is made on the upper back in children.
Previous research has shown us which fruits are most commonly involved in LFS based on the severity of the reaction seen in reported cases. It has been established that banana, avocado, kiwi and chestnut show the most significant association with latex allergies. This group is closely followed by potato, tomato and shellfish. The clinical manifestations often seen in latex-allergic individuals who are also allergic to these fruits are urticaria (skin rash), angioedema (swelling under the skin), oral allergy syndrome (inflammatory reactions in the oral cavity) and anaphylaxis (life threatening condition that blocks respiration).
Fruits like papaya, pineapple, passion fruit, mango, fig, nuts, stone fruits, melon, apple, coconut, guava, carrot, pear, strawberry, grapes have shown association's with latex allergies. However, these fruits have still not reached a level of association that can concretely make them definitive sources of LFS.
It is important to note that a latex allergy can precede or succeed the symptoms exhibited by an allergic reaction to a fruit. Moreover, it is still not clear whether a particular fruit causes a particular set of allergic reactions. Since LFS is caused by allergens that can travel in the air or spread by contact, not only do the symptoms manifest in a random order but also vary in severity.
LFS is hazardous for those people working in areas that involves the need of wearing latex gloves on a daily basis. These mainly include healthcare workers and industrial workers. If any of them have an allergy to latex and on top of that consume a fruit that can cross-react as another allergic response, it can be extremely devastating. It is reported time and again that nearly 30% of individuals with a latex allergy have an associated allergy to a fruit. Thus, LFS is a condition that is not only difficult to diagnose but whose clinical implications can be difficult to control.