Use of Total-Body PET to Quantify Systemic and Cutaneous Inflammation in Psoriasis Patients Before and After Intervention With a Nutritionally Balanced Diet

Inclusion Criteria: * Adults (\>18 year) * Both sexes * Must have a history of psoriasis of at least 3% body surface area affected by skin psoriasis (in a body area that the subject will allow the PI to perform several skin biopsies as noted below (optional)) and may carry a diagnosis of psoriatic arthritis as well * Patients will have a BMI of \>/=25 which is consistent with being overweight - Willing and able to fast for at least 6 hours before and for the duration of the scan visit * No strenuous exercise for 24 hours prior to being scanned * Recruited patients must habitually consume a WD-type diet that will be evaluated by using DHQ III food frequency questionnaire along with three-day food record14. Subsequently, the Healthy Eating Index will be calculated and participants with a poor dietary pattern (score below 58) will be eligible for the study15. Exclusion Criteria: * Those taking anti-diabetic oral or injected medications * Those already ingesting a caloric- or component-restricted diet * Vegan, vegetarian or food allergy or intolerance to the ingredients of the diet * \>5% change in body weight in the last 2 months * Those taking systemic medications for the purpose of treating psoriasis or psoriatic arthritis for at least 3 months prior to first PET scan or during the duration of the trial * Self-reported history of dysphoria or anxiety in closed spaces (claustrophobia) * Uncontrolled diabetes or blood glucose level greater than 180 mg/dl at the time of radiotracer injection * Body weight \>240 kg due to limitations of the scanner bed * Known inflammatory or other infectious disease that can confound assessment * Pregnant or breast-feeding (urine pregnancy test will be administered prior to start of each PET/CT session for all participants who are able to get pregnant between 18 to 60 years old, unless documented hysterectomy or bilateral ovarian removal is available, because of risks from ionizing radiation) * Inability to lie motionless on the scanner bed with the arms by the side for up to 60 minutes * Currently participating in another conflicting research study. Concurrent or prior enrollment in a separate research study involving a PET scan performed within the last 12 months for research purposes only. * Unwilling to sign informed consent * Inability to understand the risks and benefits of the study * Prisoners