Allergy vs. sensitisation to mandarins – rash and other symptoms
Citrus fruits are among the most frequently sensitised fruits, with oranges leading the way in terms of the frequency of allergic reactions [1]. Mandarins follow close behind. Citrus fruits can be a source of both food, contact and inhalant allergens [1]. Children who are sensitised to citrus are particularly prone to hypersensitivity to pollen (this is a result of cross-reactivity) and those with atopic dermatitis [1].
Let us not forget, however, that an allergy to mandarins is not synonymous with an allergy. An allergy, which may be indicated by allergy test results, is not always associated with adverse symptoms. An allergy to mandarins can only be said to be caused by symptoms following contact with the fruit, e.g:
- cough and allergic rhinitis,
- skin changes (rash, hives, swelling, erythema),
- nausea, vomiting, diarrhoea or constipation,
- oral allergy syndrome (itching, burning, swelling of the tongue of the lips, palate),
- itching, burning and watering of the eyes,
- stools with an admixture of blood and mucus (in infants),
- in rare cases, anaphylactic shock (drop in blood pressure) [1].
Proteins and haptens. What sensitises us in mandarins?
The allergenic proteins of which mandarins are composed are generally responsible for sensitisation and allergy in mandarins, some of which are probably still to be discovered and thoroughly investigated. From an allergological point of view, the Cit r 3 protein is particularly important. It is mainly found in the peel (which does not mean that the flesh is completely free of it). This is why some people – despite their allergy – can eat mandarins without experiencing any symptoms, because they get rid of the allergen after peeling the fruit [1].
The seeds of mandarins (which cross-react with pistachios, almonds, cashews, among others) can also prove dangerous. Although the seeds are generally not eaten, their fragments end up in fruit juices, for example, and can even cause an anaphylactic reaction [2].
Haptens, the allergens responsible for contact eczema, also contribute to symptoms after mandarins. There are known cases of allergic eczema in reaction to mandarin oil, which comes from the peel and is found in the composition of many cosmetics (washing gels, bath lotions, shampoos) or perfumes [3]. This oil can contain large amounts of limonene (above 80%), to which it owes its characteristic aroma [4]. In Poland, allergy to limonene has been detected in 7.7% of individuals qualified for routine patch testing [4].
Histamine on target
Does this exhaust the topic of mandarin allergies? Definitely not. Other factors may also be involved. To understand the complexity of the problem, let us use an example. Citrus fruits are known to contribute to an increased release of histamine in the body [5,6]. And histamine is the main mediator, or trigger, of allergic reactions. An excess of this neurotransmitter in hypersensitive individuals – with so-called histamine intolerance – can trigger, for example, an urticaria attack, but also a range of other symptoms that do not coincide with those characteristic of allergy. These include headaches and dizziness (including migraine headaches) or increased blood pressure [6].
Or are moulds to blame?
Moulds of the genus Alternaria can also be implicated in the problem of sensitisation and, in fact, allergy to mandarins. Their presence in citrus can be evidenced by a brown spot that appears on the peel – Alternaria brown. This is a common disease that affects many varieties of oranges and mandarins, thus reducing the profitability of the crop [8]. For people who are sensitised to mould fungi, eating a mandarin contaminated by Alternaria can end up with allergic symptoms.
