Lemon allergy
Lemon allergy.
About lemon allergy
Lemon is a citrus fruit used for its juice, zest and oil in drinks, cooking, baking and cleaning products. True IgE-mediated allergy to lemon is uncommon; many reactions to citrus are irritant or contact effects from the acidic juice or the oils in the peel rather than a classic food allergy. Where genuine allergy exists, the immune system makes antibodies to citrus proteins, and eating or handling lemon triggers histamine release. Some sensitisation involves widely shared plant proteins such as lipid transfer proteins or pollen-related proteins.
Reactions usually begin within minutes to a couple of hours. Symptoms may include an itchy or tingling mouth, hives, swelling and tummy upset, while contact with the peel or juice can cause localised itching, redness or a rash, particularly on the hands and around the mouth. Most reactions are mild, but more serious reactions are possible, especially where lipid transfer proteins are involved, so spreading or breathing symptoms should be treated seriously. There can be overlap with other citrus fruits such as orange and lime.
Diagnosis rests on your history, supported by skin-prick or specific-IgE testing, sometimes with fresh fruit, to distinguish allergy from irritation. Management means avoiding lemon in the forms that trigger you and reading labels, since citrus flavouring, juice and zest appear widely in foods and drinks. If you are assessed to be at risk of a serious reaction, an adrenaline auto-injector may be advised. Any severe reaction is a medical emergency: call 999.
Common triggers
- Lemon 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.