Dietary Approach to Mild-to-moderate Psoriasis
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-65
SponsorUniversity of Palermo
About this trial
Psoriasis is a systemic chronic inflammatory immune-mediated disease whose etiopathogenetic mechanisms involve genetic predisposition, and immunological and environmental factors. Its prevalence is about 3% in adults, and it is characterized by well-demarcated, erythematous plaques, covered by silvery-white scales, in elbows, knees, trunk, and scalp. However, psoriasis is far from being considered just a dermatologic condition because the cytokine's cascade, which lays behind its inflammatory and immune-mediated pathogenesis, can determine multiple systemic manifestations. In addition, several patients with psoriasis often complains of gastrointestinal (GI) symptoms. Therefore, authors focused their attention over the gut-skin axis and its possible pathogenetic and immunoregulatory role in psoriasis (i.e., altered gut barrier, increased blood concentration of gut microbiota-derived metabolites, systemic inflammation). In this context, several dietetic approaches (e.g., Mediterranean, low calories, protein-restricted, vegetarian diets, and gluten-free diet, GFD) have shown a certain efficacy in improve psoriasis cutaneous and systemic manifestations. In recent years, the existence of a wheat-related disorder in patients who do not suffer from CD or wheat allergy (WA) has been definitively ascertained and defined as Non-Celiac Wheat Sensitivity (NCWS). Its prevalence in the general population is unknown, but self-reported NCWS is around 10%. This condition is characterized by both GI and extraintestinal symptoms, which are triggered by wheat ingestion. In these patients, wheat ingestion might lead to alteration in intestinal permeability and gut microbiota and to systemic immune activation and inflammation. Based on the evidence of gut involvement in the pathogenesis and clinical manifestation of psoriasis, as well as on the ability of gluten/wheat to increase intestinal permeability, it could be hypothesized that gluten/wheat may represents one of the pathogenetic environmental factors of psoriasis and that its intake may be able to worsen symptoms in affected patients. The investigators hypothesize that a wheat-free diet (WFD) can reduce the inflammatory state and ameliorate the clinical symptoms in psoriasis patients. The successive clinical and immunologic reaction to the re-exposure to wheat ingestion, performed by an open challenge, will be also evaluated to confirm a wheat-dependent mechanism and to understand the underlining physiopathology.
Eligibility criteria
This trial does not accept healthy volunteersQualifiers
age >18 and <65 years;
no systemic therapy for psoriasis for at least 3 months before inclusion in the study;
negativity of anti-deamidated gliadin protein (anti-DGP) immunoglobulins (Ig) class A (IgA) and immunoglobulins (Ig)G, anti-tissue transglutaminase (anti-tTG) class IgA and IgG, and Endomysium antibodies (EmA);
absence of WA (negative prick-test and/or specific serum immunoglobulins (Ig)E assay for wheat, gluten, and gliadin).
Disqualifiers
severe chronic plaque-type psoriasis (based on BSA);
self-exclusion of gluten/wheat from the diet and refusal to reintroduce it, for diagnostic purposes, before entering the study;
pregnancy;
alcohol and/or drug abuse;
Trial design
Design model
Parallel
Treatments tested in this trial
Open wheat challenge
Other interventionPatients randomized to intervention diet group will have to follow a diet with elimination of wheat and cow's milk products for 2 months; after that they will be exposed to an open wheat challenge, with reintroduction of wheat. After 2 weeks of open diet, or whenever dermatologic, intestinal and/or extraintestinal symptoms should return or intensify, all patients will be revaluated and will end the study.
Placebo challenge
Other interventionPatients randomized to control diet group will have to follow a diet with elimination of rice and turkey's meat products for 2 months; after that they will crossover to a wheat and cow's milk products free diet and, finally, after 2 months, they will be exposed to an open wheat challenge, with reintroduction of wheat. After 2 weeks of open diet, or whenever dermatologic, intestinal and/or extraintestinal symptoms should return or intensify, all patients will be revaluated and will end the study.
Treatment groups
82 Participants
are divided into 2 treatment groupsGroup A: Open wheat challenge groupActive comparator 1 intervention
Group B: Placebo groupPlacebo comparator 1 intervention
Trial outcomes
Primary outcomes
1
Self-perceived non-celiac wheat sensitivity (NCWS) questionnaire in psoriasis patients
To identify psoriasis patients reporting a self-perceived NCWS; all patients will be asked to answer, consecutively, to a validated questionnaire for the self-assessment of wheat and other foods' intolerance. This is a questionnaire self-compiled by patients consisting of three sections: 1) general information (eg. age, sex, highest completed education level, etc.) 2) wheat-related symptoms (sore 0 = no symptoms, score = 1, symptoms after wheat intake; if score = 1 other question qualitatively inquire the symptoms evoked by wheat intake, eg. what kind of symptoms, how long patient perceive this problem, etc.); 3) other foods-related symptoms (score 0 = no symptoms, score 1 = symptoms after intake of other foods; if score = 1 other question qualitatively inquire the symptoms evoked by the intake of the specific food reported by the patients, eg. what kind of symptoms, how long patient perceive this problem, etc.)
Time frame
Before enter the study.2
Effect of WFD plus CMPFD in changing symptoms of psoriasis patients as assessed by BSA
To assess the effect that a WFD plus CMPFD determines in symptoms of patients affected with psoriasis the following score will be used: Body Surface Area (BSA), representing the percentage of cutaneous area affected by psoriasis.
Time frame
Start of the study (Day 0); 2 months of wheat elimination diet (Day 60).3
Effect of WFD plus CMPFD in changing symptoms of psoriasis patients as assessed by Psoriasis Area Severity Index
To assess the effect that a WFD plus CMPFD determines in symptoms of patients affected with psoriasis the following score will be used: Psoriasis Area Severity Index (PASI), a composite evaluation for psoriasis severity, subscoring for erythema, induration, scaling, and percentage of body-surface area affected. The rating scale includes 4 levels: No Psoriasis, Mild Psoriasis, Moderate Psoriasis, and Severe Psoriasis.
Time frame
Start of the study (Day 0); 2 months of wheat elimination diet (Day 60).4
Effect of WFD plus CMPFD in changing symptoms of psoriasis patients as assessed by IGA
To assess the effect that a WFD plus CMPFD determines in symptoms of patients affected with psoriasis the following score will be used: Investigator's Global Assessment (IGA), a 5-point instrument for rating the clinician's impression of the overall severity of the psoriasis, from 0, clear skin, to 4, severe disease.
Time frame
Start of the study (Day 0); 2 months of wheat elimination diet (Day 60).Secondary outcomes
1
Effect of open wheat challenge in symptoms changing of psoriasis patients as assessed by BSA
To evaluate, by an open wheat challenge, the frequency of a coexistent NCWS condition in psoriasis patients, both of the intervention group (T2int) and the control group (T3con). The following score will be used: Body Surface Area (BSA), representing the percentage of cutaneous area affected by psoriasis.
Time frame
Day 60; 2 weeks of open wheat challenge (Day 75).2
Effect of open wheat challenge in symptoms changing of psoriasis patients as assessed by Psoriasis Area Severity Index
To evaluate, by an open wheat challenge, the frequency of a coexistent NCWS condition in psoriasis patients, both of the intervention group (T2int) and the control group (T3con). the following score will be used: Psoriasis Area Severity Index (PASI), a composite evaluation for psoriasis severity, subscoring for erythema, induration, scaling, and percentage of body-surface area affected. The rating scale includes 4 levels: No Psoriasis, Mild Psoriasis, Moderate Psoriasis, and Severe Psoriasis.
Time frame
Day 60; 2 weeks of open wheat challenge (Day 75).3
Effect of open wheat challenge in symptoms changing of psoriasis patients as assessed by IGA.
To evaluate, by an open wheat challenge, the frequency of a coexistent NCWS condition in psoriasis patients, both of the intervention group (T2int) and the control group (T3con). The following score will be used: Investigator's Global Assessment (IGA), a 5-point instrument for rating the clinician's impression of the overall severity of the psoriasis, from 0, clear skin, to 4, severe disease.
Time frame
Day 60; 2 weeks of open wheat challenge (Day 75).4
Effect of open wheat challenge in symptoms changing of psoriasis patients as assessed by GSRS.
To evaluate, by an open wheat challenge, the frequency of a coexistent NCWS condition in psoriasis patients, both of the intervention group (T2int) and the control group (T3con).The following score will be used: Gastrointestinal Symptom Rating Scale (GSRS), assessment scale for irritable bowel syndrome-like and functional dyspepsia-like symptoms, providing for a score ranging from 15 to 60).
Time frame
Day 60; 2 weeks of open wheat challenge (Day 75).Sponsors and contacts
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University of Palermo
Lead sponsor
Aurelio Seidita
Collaborator
Source ClinicalTrials.gov