Urticaria and food sensitivities

Food allergies or food sensitivities

A food allergy is an abnormal immunological response to a food or food component, usually a naturally occurring protein or partially digested food products. The risk of developing food allergy depends on heredity, exposure to a food (antigen), gastrointestinal permeability and environmental factors. True IgE-mediated food allergy usually develops in infancy, most often in those with a strong family history of atopy. The first manifestation may be atopic dermatitis alone or in association with gastrointestinal symptoms; the more severe the atopic dermatitis in young children, the more likely they are to have food allergy.

Food allergy symptoms can include:

·         Gastrointestinal symptoms (nausea, vomiting, colic, diarrhoea, malabsorption, blood in stools)

·         Skin symptoms (rashes, atopic dermatitis, urticaria, angioedema)

·         Respiratory symptoms (wheezing, asthma, rhinitis)

·         Neurologic symptoms (migraine)

·         Joint symptoms (arthralgia, arthritis)

·         Psychologic symptoms (behaviour problems, hyperactivity, reduced attention span).

 

Urticaria (Hives)

Urticaria (hives) is characterised by oedematous plaques, called wheals, that are accompanied by intense itching. Wheals typically appear as raised pink or red areas surrounded by a paler halo. Thicker lesions that result from massive transudation of fluid into the dermis or subcutaneous tissue are referred to as angioedema. Angioedema typically affects the larynx, causing hoarseness or sore throat, or the mucosal surface of the gastrointestinal tract, causing abdominal pain. Acute urticaria and angioedema are essentially anaphylaxis limited to the skin and subcutaneous tissues. Individuals with atopy are most likely to experience urticaria, and increased gut permeability and food allergies may play a key role in the instigation and prolongation of immune activity that leads to chronic urticaria.

The most common causes of acute urticaria are foods or drinks, medications or exposure to pollens or chemicals. Food is the most common cause of acute urticaria in children. Chronic urticaria (persisting for longer than six weeks) primarily affects adults, especially women, and can be associated with autoimmune thyroid disease (e.g. Hashimoto’s thyroiditis, Graves’ disease, toxic multinodular thyroiditis).