Do you experience red rashes or swollen lips while eating or washing a specific type of fruit? You may have a fruit allergy. Fruits, are generally considered healthy to our diet, but certain individuals may develop allergic reactions to different fruits.

Fruit allergy

Fruit allergy is a type of food allergy that occurs when your body considers fruit as a foreign threat and releases chemicals known as histamines as an overprotective response. The emergence of fruit allergies has added a layer of complexity to our dietary landscape. 

Plums

Among different fruits allergies, plum allergies , once considered relatively uncommon, are now gathering attention due to rising prevalence of fruit allergies. Plum allergies are one of the most common fruit allergies in southern Europe. Plums,  a medium sized single stoned fruit closely related to cherries and peaches, belong to the genus prunes, family Rosaceae. Plums are cultivated across the world. Two types of plums are cultivated commercially:

1. European plum (P. domestica)
2. Japanese plum (P. salicina)

Plums are edible and are eaten as raw fruit, cooked or baked as in pastries. 

Plum allergens

The culprits in plum allergies are the following proteins that can trigger your body’s immune response leading to allergic symptoms. 

• Pru d 1, a Bet v 1 homologue. 
• Pru d 2, a Thaumatin-like protein (TLP). 
• Pru d 3, a 9 kDa lipid transfer protein. 
• Pru d 4, a profilin 

Profilins are considered to be panallergens as they have the potential to cause reactions over large groups of foods. Pru d 3, a 9 kDa lipid transfer protein is the most commonly associated with plum allergy. 

Potential cross reactivity

Extensive cross-reactivity occurs between the fruit of the different individual members of the Rosaceae family. Cross-reactivity can occur if you are allergic to some food or allergens, then you may possibly get allergic to some related fruit or food.

Oral allergy syndrome

One common cross reactivity is known as oral allergy syndrome. Also known as pollen allergy syndrome. Oral allergy syndrome is a form of allergy that happens when your mouth or throat get contact with raw fruits or vegetables. This happens when your body’s immune system wrongly recognizes the similarity between pollen and the protein in raw fruit. The following are the types of pollen and their related fruits that may cause oral allergy syndrome.

• Birch pollen: apple, apricot, cherry, kiwi, peach, pear, and plum.
• Grass pollen: melon, orange
• Ragweed pollen: banana, melon
• Mugwort pollen: peach

So people who are allergic to hay fever or the pollen of birch trees or have birch pollen allergy may develop an allergy to plum. This occurs because of the similarity between birch pollen and the plum protein, Pru d 1, a Bet v 1 homologue. This type of allergy is common in the north of europe.

LTP syndrome

If you have an allergy to peach you may also develop an allergy to plum. This is because of Pru d 3, a 9 kDa lipid transfer protein present in plums, which is homologous to  Pru p 3, a non-specific lipid transfer protein type 1 (nsLTP 1), the major allergen of peaches. LTP cross reactivity may also result in cross reactivity with other LPT containing food such as the LTPs of Rosaceae fruits (peach, apricot, cherry, plum and apple). This type of allergy is common in Mediterranean atopic populations.

Symptoms

Signs and symptoms that may appear because of plum allergy are the following:

• Redness
• Itching of lips, face
• Swelling of throat
• Nausea
• Abdominal pain
• Vomiting
• Sneezing 
• Runny nose
• Anaphylaxis (extreme symptom)

Diagnosis

If you have any of these symptoms while eating a specific type of fruit. You should consult your doctor. Your doctor would ask you about your history and would likely recommend the following tests for allergy diagnosis. 

• Skin test : The suspected allergen is exposed to your pricked skin and the reaction is observed by your healthcare professional.
• Blood test: your blood is drawn and a test is done to identify the specific antibodies.
• Patch test: The suspected allergens are added to a specialised disc and taped with your body for 48 hours and then reactivity is observed by your doctor.
• Food test: Food is consumed in smaller amounts, gradually increasing under super closed supervision.

Treatment:

This may be through:

• Suspected fruit avoidance
• Antihistaminesto help treat your symptoms
• An epinephrine auto injector.

Summary

Plum allergies are triggered by  proteins known as Pru p 1 and Pru p 3, concealed within the sweet flesh of plums. Symptoms range from a subtle tingling around the mouth to more severe manifestations like hives or even anaphylaxis. Recognizing these signs early becomes paramount for effective management and timely intervention.

FAQs

Can plum allergies develop later in life, or are they usually present from childhood?

Answer: Plum allergies, like many food allergies, can develop at any stage of life. Some individuals may have allergic reactions to plums from an early age, others may develop sensitivity later in life. It highlights the importance of remaining vigilant to potential allergic responses, even if there hasn't been a prior history of plum allergies.

Are there other fruits that individuals with plum allergies should be cautious about due to cross-reactivity?

Answer: Yes, Cross-reactivity is a noteworthy aspect of plum allergies. The culprits of plum allergy may share similarities with those in other fruits, and pollens potentially triggering allergic responses. Fruits like cherries, apricots, and peaches are known to have cross-reactivity with plums. Being aware of these potential triggers helps individuals make informed dietary choices while maintaining a varied fruit intake.

Can plum allergies be outgrown over time, or are they lifelong conditions?

Answer: Some food allergies can be outgrown, but plum allergies often persist into adulthood. It's important for individuals diagnosed with plum allergies to have regular assessments and discussions about the potential evolution of allergies ensuring appropriate management and support throughout different stages of life.

How can someone with plum allergies ensure a nutritionally balanced diet without compromising on taste?

Answer: With creativity and nutritional awareness, a balanced diet without plums can be achieved. A dietitian can help identify alternative sources of essential nutrients typically found in plums. Exploring a variety of fruits that do not trigger allergic responses, such as apples, pears, or berries, allows for a rich and diverse dietary experience while meeting nutritional needs. Moreover, seeking out allergy-friendly recipes and adapting them to personal preferences can add an extra layer of enjoyment to the culinary journey.