Understanding Soya Allergy: Symptoms, Causes, and Management

Soya allergy is a common food allergy caused by the immune system reacting to proteins found in soybeans. While typically seen in infants and young children, it can also affect adults. In the UK, approximately 4 in 1,000 children are diagnosed with this condition.

Symptoms of Soya Allergy

Symptoms of a soya allergy can vary in severity and onset time, with some appearing immediately and others being delayed:

  • Mild reactions: Itchy throat, hives (rash), swelling (around the lips or eyes), nausea, vomiting, or diarrhoea.
  • Severe reactions (Anaphylaxis): Breathing difficulties, throat swelling, dizziness, or fainting. Anaphylaxis requires urgent administration of adrenaline and a call to 999.

Causes and Triggers

Soya allergy occurs when the immune system identifies proteins in soybeans as harmful, prompting an overreaction. Key risk factors include:

  • Family history: A genetic predisposition to allergies, eczema, or asthma.
  • Existing allergies: Individuals allergic to cow's milk are more likely to develop a soya allergy.

Hidden Sources of Soya

Soya is found in a wide variety of foods, not all of which are obvious. These include:

  • Processed snacks and meals: Crisps, ready-made meals, pot noodles.
  • Baked goods: Many supermarket breads and pastries contain soya flour.
  • Condiments: Soy sauce and other seasonings.
  • Meat substitutes: Tofu, tempeh, and textured vegetable protein.

To avoid exposure, always check food labels for terms like soya, hydrolysed vegetable protein, or bean curd.

Diagnosis

If a soya allergy is suspected, a medical diagnosis involves:

  1. History of symptoms: Documenting typical reactions after consuming soya.
  2. Allergy tests: Skin prick or blood tests for specific IgE antibodies.
  3. Oral challenge: Controlled consumption of soya under medical supervision.

Management and Treatment

  • Mild symptoms: Antihistamines can help reduce reactions like hives or itching.
  • Severe reactions: Use adrenaline auto-injectors immediately and call 999 if anaphylaxis occurs.
  • Avoidance: Meticulously check ingredient labels and avoid foods containing soya.

Who Is Most at Risk?

Soya allergy is most common in children, with many outgrowing it by age 10. However, adults with other food allergies or asthma are at a higher risk of severe reactions.

Key Precautions

  1. Label awareness: Always scrutinise packaging for potential allergens.
  2. Inform others: Share allergy details with schools, carers, and restaurants.
  3. Carry emergency medication: Always have two adrenaline auto-injectors available.

For further information, consult trusted resources like the NHS, Allergy UK, or Anaphylaxis UK.

Note: This article is intended for informational purposes and should not replace professional medical advice.