Helpline1. Food allergies do not cause eczema. In children with eczema and food allergy, the food allergy may trigger eczema symptoms following an ‘immediate or ‘delayed’ reaction but it is not the cause of the eczema. Food allergy can make eczema worse in two ways:
- Immediate reactions: Exposure by ingestion or contact with the skin by the food allergen can cause allergic symptoms e.g. hives, vomiting, swelling of the eyes, lips or face. This usually happens within minutes of exposure and may also cause the eczema to flare during this acute reaction.
- Delayed reactions: These can occur several hours or days after exposure and can be seen in children where eczema remains persistent and problematic despite adhering to the management (see below).
2. The key pillars of good eczema management include maintaining, protecting, and treating the skin barrier with topical treatments.
The foundations of this are:
- Applying a good quality emollient to help restore the barrier function of the skin at least twice a day head to toe. It is also advisable to avoid creams or lotions that contain food products due to the possibility of cutaneous sensitisation to food allergens via a defective skin barrier.
- Washing using a non-soap-based product e.g. an emollient that doubles up as a soap substitute, or a gentle wash or oil in the bath or shower. Applying an emollient after washing helps to lock in moisture and maximize its hydrating effect.
Treating eczema flares with topical steroids, which should be prescribed in a strength to match the severity of the eczema. Patient education on how and when to use it is key to combating corticosteroid hesitancy. The introduction of new labelling requirements by the MHRA later this year will help inform patient about the potencies of the steroids they have been prescribed and streamline the advice to patients needing multiple steroid medications of different potencies. More information can be found here.
More detailed information can be found at [Eczema in children factsheet] which is a useful signpost for parents of children with eczema and available to download from the Allergy UK website.
3. Food allergy prevention: There is growing evidence to support that skin-centered strategies such as the preventative application of emollients that help to maintain a healthy skin barrier, can help prevent the development of food allergy (4). Where there is a disruption to the normal function of the skin barrier, there is a risk of epicutaneous sensitisation to allergens. One of the theories underpinning this comes from the ‘dual allergen hypothesis’ which suggests that early life, low dose allergen exposure via an impaired skin barrier -as is seen in conditions like eczema – has the potential to induce allergic sensitisation (1). Previously this was only understood to occur via oral ingestion of a food.
4. Clinical allergy testing for food culprits in eczema management such as skin prick tests or specific IgE blood tests for food allergy are, in most cases, not helpful as they do not predict foods that are making the eczema worse. Allergic sensitisation may be evident in the absence of allergic signs and symptoms which can also confuse the picture. Food elimination diets can be useful to help diagnose non-IgE mediated food allergy. This involves removing the suspected food culprit from the diet for a defined period (usually 2-4 weeks) and re-introducing it to see if symptoms improved, resolved or remained the same on dietary exclusion. It is also important to record what happened when re-introduced.Food can also worsen eczema without an allergic origin. Some of the more common culprits include strawberries, tomatoes and citrus fruits. These foods do not need to be eliminated from the diet but can be included as tolerance allows. These are less likely to be problematic when eczema is well managed.
Allergy testing should only be requested by a Health Care Professional with the appropriate knowledge and understanding to take a detailed allergy focused history to highlight the suspected allergen(s) and one who is able to interpret and manage the results e.g. an allergy/immunology specialist (2).
5. Dietary exclusions: Removal or avoidance of one or more food groups from a child’s diet without using the right substitutes can cause malnutrition and result in poor growth. This should only be done under the guidance of a specialist e.g. an allergy doctor and/or dietitian. It also can increase the risk of allergies developing or cause existing ones to worsen. Instead, another strategy for allergy prevention is the early introduction and continued regular consumption of typically allergic foods. This is thought to be protective against the development of IgE mediated allergy to that food (3). More information on Early feeding guidance for Health Care Professionals can be found here.
Summary:
Having a better understanding of the relationship between these two allergic disease manifestations will help improve patient care pathways.
Whilst the landscape for managing allergic diseases is evolving with many different treatment options on the horizon, there is a need to get back to basics with eczema management and education, in order to provide improved care to families living with food allergy and eczema.
References:
- Lack G. Update for risk factors for food allergy. Journal of Allergy and Clinical Immunology. 2012: 129: 1187-1197.
- NICE Clinical guideline Food allergy in under 19s: assessment and diagnosis 2011 Accessed 04/09/2024 Food allergy in under 19s: assessment and diagnosis (nice.org.uk)
- Sakihara T. Regular consumption following early introduction of allergenic foods and aggressive treatment of eczema are necessary for preventing the development of food allergy in children. Current opinion, Allergy and Clinical Immunology. 2024 1;24 (3): 160-165.
- Tham E. et al, Role of skin management in the prevention of atopic dermatitis and food allergy. 2024: 35: 3.