Antibody profiles are available to assess the body’s reaction to a wide range of food components, food additives and other environmental allergens i.e., chemicals and environmental toxins. Some tests target the causes of immediate allergic (IgE) reactions and others assess delayed sensitivity (IgG) reactions or intolerances i.e., lactose intolerance which can arise hours or days after exposure to the offending food.

Not all tests are equal and the successful use of laboratory testing is dependent on choosing the right test. Once a history and symptoms have been assessed to provide an indication of where to place the diagnostic focus – a whole body system, a specific nutrient status, or an individual metabolic pathway – the key is to choose the most relevant test for the analyte. For example, even though serum tests are available for both fat and water soluble nutrients, they are only a good indictor of fat soluble nutrient status, while specific urine tests are a far more accurate method for assessing the status of water soluble nutrients such as B Vitamins.

In addition, just as with other branches of science, biochemical testing and medicine has benefited from continued research, which has resulted in the development of advanced laboratory methods. This includes the advancement, and scientific validation of ‘non invasive’ tests for the accurate assessment of many analytes.

The majority of adverse immune reactions to foods classified as type II, III, or IV with delayed system onset, are mediated by IgG and are termed food sensitivities. It has been estimated that 90% of immune reactions to foods are non-IgE or delayed symptom onset food allergies. A single blood test can identify patient’s food sensitivities. Recommended treatments for food sensitivities is elimination of reactive foods from the diet for a period of 3 to 4 months followed by reintroduction and rotation. This test, tests for 115 foods.

Allergy Profiling:

The ImmunoCAP Allergen Component Specific IgE blood test is the most comprehensive method of screening, enabling detection of specific antibodies (sIgE) to 112 allergenic components in one test, including airborne allergens, food and stinging insect venoms. Immunoglobulin (Ig) E-mediated allergic diseases are increasing rapidly, affecting the quality of life of millions of people and causing enormous costs for society. Accurately identifying the sensitising allergen and its sources is one of the cornerstones in the clinical management of allergic patients.

There are several individual tests available and there are specific profiles available that include multiple tests:

• ALEX Allergy Test (300 allergens)
• ISAC Panel (48 preselected allergen sources)
• Atopic Rhinitis/Asthma Profile
• Atopic Dermatitis/Eczema Profile (14 Allergens)
• Histamine Releasing Urticaria Test
• Allergy x 5 single individual Allergens
• Allergy x 10 single individual Allergens

The Gut-Histamine Connection.

For many patients, symptoms such as bloating, food reactivity, itching, flushing, and chronic skin irritation are often treated in isolation.

However, emerging clinical evidence highlights a close relationship between gut microbiome imbalance and histamine regulation, with implications not only for digestive health, but also for systemic inflammation and skin conditions such as eczema (atopic dermatitis).

How SIBO Influences Histamine Activity:

Small Intestinal Bacterial Overgrowth (SIBO) is increasingly recognised as a contributor to both gastrointestinal and extra-intestinal symptoms.

Certain bacterial strains associated with SIBO are known to:

1. Produce histamine within the gut (histamine-secreting bacteria)
2. Disrupt intestinal barrier function, increasing immune activation
3. Reduce DAO enzyme activity, impairing histamine breakdown

This combination can lead to elevated circulating histamine levels—an effect described in microbiome research exploring the gut–immune–skin axis.

The Clinical Importance of DAO Testing:

The DAO (diamine oxidase) enzyme plays a central role in degrading dietary histamine within the gut. Reduced DAO activity has been associated with histamine intolerance syndromes, where patients develop symptoms despite the absence of classical IgE-mediated allergy (Maintz & Novak, American Journal of Clinical Nutrition).

DAO testing provides a clinically useful marker of histamine clearance capacity. When levels are low, histamine accumulation may contribute to:

1. Pruritus (itching), even without visible rash
2. Urticaria (hives) and flushing
3. Exacerbation of inflammatory skin conditions, including eczema

Histamine is also a recognised mediator in atopic dermatitis, contributing to itch signalling and inflammatory cascades (supported by dermatology and immunology literature). By assessing DAO function, we can differentiate histamine intolerance from:

1. Mast Cell Activation Syndromes (MCAS)
2. IgE-mediated food allergies
3. Non-specific food sensitivities

This distinction is essential for guiding appropriate, targeted treatment.

The Clinical Presentation

Patients with this combined gut–histamine pattern often report:

Persistent abdominal bloating and discomfort

1. Itching, with or without visible skin changes
2. Eczema flares associated with food intake or gut symptoms
3. Flushing or hives following certain foods
4. Fatigue, headaches, or cognitive fog
5. Increasing food intolerance over time

In such cases, eczema may reflect not only a dermatological condition, but a systemic inflammatory response influenced by gut and immune function—a concept supported by growing research into the gut–skin axis.

Why Conventional Approaches Often Fall Short

Treating symptoms in isolation can lead to incomplete outcomes:

1. Dermatological treatment without addressing histamine pathways
2. Dietary restriction without identifying microbial imbalance
3. SIBO treatment without supporting histamine metabolism

Clinical experience, supported by evolving literature, suggests that integrated management leads to more sustained improvement.

A More Refined Diagnostic Strategy

At our clinic, we prioritise identifying the underlying mechanism through targeted investigation:

SIBO breath testing to assess microbial overgrowth and DAO enzyme testing to evaluate histamine degradation capacity.

This enables a more precise understanding of whether symptoms are driven by Microbiome imbalance and Impaired histamine processing, Or a combined gut–immune–skin pathway.

A Personalised Treatment Approach

Where these pathways are involved, treatment is carefully structured to reduce both gut and skin inflammation:

1. Targeted management of bacterial overgrowth
2. Low-histamine nutritional strategies
3. DAO enzyme support, where appropriate
4. Restoration of gut barrier integrity and motility

This approach reflects a systems-based model of care, increasingly recognised in functional gastroenterology and integrative dermatology. For patients with persistent eczema, itching, or food-related skin reactions, understanding the gut–histamine connection can be transformative.

A structured, clinically guided assessment provides clarity—and a treatment strategy grounded in both evidence and clinical experience.

SIBO Breath Test:

If you’re struggling with persistent bloating, excess gas, abdominal discomfort, constipation, or diarrhoea, the underlying cause may not be “IBS” alone.

One of the most common, and often overlooked causes is SIBO (Small Intestinal Bacterial Overgrowth) or intestinal methanogen overgrowth (IMO).

A SIBO breath test is a non-invasive diagnostic test that measures the levels of hydrogen and methane gas in your breath after consuming a specific sugar solution (usually glucose or lactulose). These gases are produced by bacteria (or methanogens) in the small intestine and absorbed into the bloodstream, then exhaled—allowing us to detect abnormal microbial activity.

What Do the Results Mean?

High hydrogen levels:
Suggest hydrogen-dominant SIBO
Often linked to bloating, diarrhoea, and abdominal discomfort

High methane levels:
Indicates intestinal methanogen overgrowth (IMO)
Strongly associated with constipation, sluggish digestion, and delayed gut motility

Symptoms That May Suggest SIBO:

1. Ongoing bloating (especially after eating)
2. Excessive gas or belchingAbdominal pain or distension
3. Constipation or diarrhoea
4. Feeling uncomfortably full after small meals“IBS” symptoms that haven’t improved with standard treatments

Why Proper Testing Matters?

Many patients are treated with acid suppression medications, broad elimination diets and general IBS protocols. However, if bacterial overgrowth is the root cause, these approaches often don’t resolve the problem.

A SIBO breath test allows us to:

1. Identify the exact pattern of overgrowth
2. Target treatment appropriately
3. Avoid unnecessary or ineffective therapies

A Comprehensive approach to Allergy, Skin and Gut Health:

At our clinic, we take a precision-based approach to allergy profiling and chronic symptom management, recognising that conditions such as eczema, chronic itching, urticaria, food reactions, and IBS-type symptoms are often interconnected. Advanced testing, including ImmunoCAP component-resolved diagnostics, ALEX allergy testing (300 allergens), ISAC panels, and targeted atopic profiles, allows us to accurately identify IgE-mediated allergies, environmental triggers, and food sensitivities. However, for many patients, symptoms extend beyond classical allergy pathways. The growing understanding of the gut–histamine–skin axis highlights how SIBO (small intestinal bacterial overgrowth), impaired DAO enzyme activity, and histamine dysregulation can drive both digestive symptoms and inflammatory skin conditions such as eczema. By integrating allergy testing with SIBO breath testing and DAO assessment, we are able to distinguish between true allergy, histamine intolerance, and microbiome-driven inflammation, ensuring a more targeted and effective treatment strategy. This joined-up, systems-based model—bridging dermatology, gastroenterology, and immunology—offers a more complete understanding of complex, persistent symptoms and supports long-term resolution rather than temporary symptom control.