Citrus allergy
Allergy or sensitivity to citrus fruit.
About citrus allergy
Citrus fruits include oranges, lemons, limes, grapefruit and their relatives. True IgE-mediated allergy to citrus is uncommon; many reactions people describe are actually irritation or intolerance. The natural acids and compounds in citrus can irritate the lips and mouth, and citrus is fairly high in histamine-releasing substances, so tingling, redness or an upset stomach after eating does not always mean a genuine immune-based allergy. Where real allergy exists, the immune system produces IgE antibodies to citrus proteins.
Symptoms of an irritant reaction tend to affect the lips and mouth soon after contact, causing tingling, redness or a rash around the mouth, especially in children. True allergic reactions usually begin within minutes to two hours and may include an itchy mouth, hives, swelling and stomach upset, with severe whole-body reactions being rare. Some people react to citrus peel or the oils in the peel more than the flesh, and handling the fruit can cause skin irritation in sensitive individuals.
Diagnosis relies on a careful history and food diary to separate irritation from true allergy, supported where needed by skin-prick or specific-IgE blood tests through an allergy specialist. Management depends on the cause and usually involves avoiding the fruit or juice that provokes symptoms and being aware of citrus flavourings and peel in foods and drinks. Most reactions are mild, but if any reaction involves breathing difficulty, throat swelling or faintness, treat it as an emergency and call 999.
Common triggers
- Citrus and products containing it
Symptoms
- Itching or tingling in the mouth
- Hives, itching or eczema
- Swelling of the lips, face, tongue or throat
- Stomach cramps, nausea, vomiting or diarrhoea
- Wheezing or trouble breathing
- In severe cases, anaphylaxis
Avoidance & management
- Read ingredient labels every time
- Ask about ingredients and cross-contamination when eating out
- Keep the food out of shared cooking areas
- Carry prescribed antihistamines or an adrenaline auto-injector
- Seek emergency help for any severe reaction
Sources & references
Allergy safety: what everyone should know
Mild-to-moderate reaction signs
- Itching, hives or a raised rash
- Swelling of lips, face or eyes
- Tingling mouth, sneezing, runny nose
- Stomach pain, nausea or vomiting
Anaphylaxis — call 999 (UK) or 112 (EU) immediately
- Difficult or noisy breathing, wheeze, persistent cough
- Swelling of the tongue or tightness in the throat
- Dizziness, collapse, pale and floppy (young children)
- Use an adrenaline auto-injector (e.g. EpiPen) at once if prescribed, then call an ambulance even if symptoms improve
Allergy or intolerance? A true allergy involves the immune system and can escalate quickly; an intolerance (e.g. lactose intolerance) is unpleasant but not life-threatening. The symptoms overlap, so self-diagnosis is unreliable.
Getting tested: home-testing kits based on IgG are not diagnostically valid. If you suspect an allergy, ask a GP for referral to an allergy clinic for skin-prick or specific-IgE testing and a supervised food challenge where appropriate.