Psoriasis Testing. A Functional Medicine Approach to Understanding Root Causes
- Muriel Wallace-Scott
- Oct 3
- 4 min read
Updated: Oct 26
Psoriasis is far more than a skin condition. It is an autoimmune disease, driven by inflammation and immune dysregulation that affects the body well beyond the surface. Although topical creams, systemic medication and biologics can help manage symptoms, they do not necessarily explain why the immune system has become reactive in the first place. This is where carefully selected psoriasis testing can make a meaningful difference.
GP bloodwork, such as vitamin D status, thyroid function, ESR and CRP, is often the first step. These are important, but many people continue to struggle with recurring flares despite being told that everything looks normal. When that happens, functional testing can help uncover deeper contributors to immune imbalance.
Effective psoriasis care is not about ordering a long list of tests. Functional medicine focuses on targeted assessment based on a detailed history, symptoms and clinical suspicion. Sometimes no additional testing is required at all. The goal is to understand the unique drivers behind your condition and select tests only if they help guide decisions.
Why Psoriasis Testing Matters
Research shows that people with autoimmune psoriasis often have underlying factors that remain undetected with standard investigations. These can include:
Gut dysbiosis and increased intestinal permeability
Nutrient deficiencies including vitamin D, zinc, selenium and omega-3 fatty acids
Coexisting autoimmune issues such as coeliac disease or thyroid autoimmunity
Elevated cardiovascular and metabolic risk linked to ongoing inflammation
Environmental and immune triggers not routinely screened for in primary care
Because psoriasis is rarely an isolated issue, identifying these root causes can support long-term healing and improve overall health outcomes.
Stool Testing. The Gut–Skin–Immune Axis in Psoriasis
Increasing evidence shows that the gut plays a central role in skin and immune regulation. A stool test can be one of the most informative options when IBS like symptoms, bloating, diarrhoea, constipation or food reactions accompany psoriasis.
A comprehensive analysis can assess:
Microbiome balance
Digestive enzyme activity and nutrient breakdown
Overgrowths such as yeasts, parasites or inflammatory bacteria
Markers of intestinal permeability (leaky gut)
Local immune response indicators like secretory IgA
Not everyone with psoriasis requires stool testing, but it becomes highly relevant when the gut appears to be contributing to immune inflammation.
Nutrient Testing. Supporting Rapid Skin Turnover
Because skin renewal is accelerated in psoriasis, nutrient demand increases. If nutrient depletion is suspected, testing can be used to personalise support.
Important examples include:
Vitamin D for immune modulation
Zinc and selenium for healing and antioxidant function
Magnesium for inflammation and cellular repair
Essential fatty acids to support skin barrier and reduce inflammatory pathways
B vitamins to support methylation and detoxification
Sometimes clinical assessment alone justifies targeted supplementation, while in other cases lab data can prevent guesswork and guide dosage.
Immune and Inflammatory Marker Testing
Standard inflammatory markers only show part of the picture. When symptoms suggest more widespread immune activity, functional tests can assess:
Oxidative stress and cellular inflammation
Metabolic function and cardiovascular risk
Immune regulatory pathways linked to autoimmunity
These advanced markers are not essential in every case but can help monitor systemic involvement and guide treatment.
Histamine and Mast Cell Activation Testing
People with psoriasis frequently report histamine-related symptoms such as itching, flushing, headaches and digestive upset. Mast cells influence both inflammation and skin reactions.
Functional histamine testing may include:
DAO enzyme activity to assess histamine breakdown
Plasma histamine levels
Mast cell markers such as tryptase
This information can support dietary and therapeutic interventions where histamine sensitivity is suspected.
Environmental Testing. When Exposure Drives Immune Overload
Some individuals experience worsening psoriasis when living in damp or mould-affected environments. CIRS (Chronic Inflammatory Response Syndrome) testing may be considered only when there is a clear exposure history or highly suggestive symptoms.
Potential markers include:
HLA-DR genetic testing for susceptibility
VCS testing as a screening tool for neuroinflammation
Specific inflammatory markers such as TGF-beta1 and MMP-9
MARCoNS testing when sinus colonisation is suspected
This type of testing is highly specialised and only appropriate in a subset of psoriasis cases.
Interpreting Results in Context
Testing should always support, not replace, expert clinical reasoning. In practice:
If long-standing gut symptoms exist, stool testing may provide clarity
If itching and flushing are prominent, histamine assessment becomes relevant
If environmental exposure is a concern, CIRS testing can be justified
In many situations, we can begin with supportive interventions first and reserve testing for when progress is slow or uncertainty remains.
The objective is precision, not excess.
A Targeted, Personalised Path Forward
At The Autoimmune Clinic, psoriasis testing is used selectively and thoughtfully. We consider your history, symptoms and priorities first, and collaborate with you to decide whether testing is necessary. Sometimes the most profound improvements begin before any lab assessments take place, simply by addressing nutrition, lifestyle, gut health and environmental exposures.
Testing is a tool. Your body’s story is the guide.
If you are living with psoriasis and want deeper insight into what is driving inflammation for you, we would be happy to help.
You are welcome to book a discovery call to discuss your symptoms and the most appropriate next steps for your health.
A Note on Functional TestingNot every client needs every test. At The Autoimmune Clinic, we do not recommend ordering every test available. Functional testing is most valuable when it helps to confirm or rule out suspected drivers of inflammation. Sometimes no testing is needed at all, and meaningful progress can be made with history-taking, diet, lifestyle, and environmental adjustments. Your practitioner will help you decide:
The goal is not to collect data for the sake of it, but to use the right tools, at the right time, to guide your healing journey. |
