Psoriasis is a chronic inflammatory skin disease that affects approximately 2% of the global population and is frequently associated with psychiatric comorbidities such as anxiety and depression. Although conventional treatments, including topical corticosteroids and biologic agents, may be effective, many patients face challenges related to treatment adherence, adverse effects, and the psychosocial impact of the disease. This open label study aims to investigate the efficacy and acceptability of medicinal cannabis formulations administered orally and topically in the management of mild to moderate psoriasis. 37 participants will be included and will use full spectrum cannabis formulations in the (1:1:1) CBD:CBG:THC ratio at a concentration of 20 mg/ml. The protocol will have a total duration of 180 days, consisting of 60 days of isolated treatment followed by 120 days of combined treatment. Efficacy will be assessed using validated instruments, including PASI, DLQI, BDI II and BAI, the Visual Analog Scale for pruritus intensity, the Cosmetic Acceptability Scale, and the Treatment Satisfaction Scale. The use of cannabis formulations is expected to promote clinical improvement of skin lesions, reduction of subjective symptoms such as pruritus and discomfort, and a positive impact on patients quality of life. This study seeks to contribute to the generation of evidence, regarding the efficacy, safety, and acceptability of therapeutic cannabis use in the dermatological context.
This study aims to evaluate the effects of oral and topical cannabinoid administration in patients with psoriasis over a 180-day period. Oral administration will be performed using a full-spectrum extract containing CBD:CBG:THC in a 1:1:1 ratio, with a concentration of 20 mg/mL of each cannabinoid. Dose titration will be conducted progressively according to individual tolerability. The dosing schedule will follow a stepwise escalation: 0.08 mL/day in the first week (approximately 1.6 mg/day of each cannabinoid), 0.17 mL/day in the second week (approximately 3.3 mg/day of each cannabinoid), and 0.25 mL/day in the third week (5 mg/day of each cannabinoid). From the second month onward, the dose will be increased to 0.5 mL/day (10 mg/day of each cannabinoid), defined as the maximum study dose, and maintained until the end of the intervention period. Topical administration will be performed using a cream containing CBD:CBG:THC, in the same proportion as the oral extract, with a concentration of 20 mg/mL of each cannabinoid. The product will be applied directly to psoriasis lesions twice daily throughout the study period. No titration will be performed for the topical formulation, and a fixed-dose regimen will be maintained. The study will follow a two-phase design. Participants will be initially allocated into two groups: Group 1 (oral) will receive the oral extract for the first 60 days, while Group 2 (topical) will use the topical formulation during the same period. In the second phase (days 60-180), all participants will receive combined treatment (oral extract plus topical formulation). This design allows evaluation of both isolated and combined therapeutic effects.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
37
Oral administration of a full-spectrum cannabis extract containing CBD, CBG, and THC in a 1:1:1 ratio, with a concentration of 20 mg/mL of each cannabinoid. Dose titration will be performed progressively according to tolerability, followed by maintenance at the maximum dose.
Topical formulation containing CBD, CBG, and THC in a 1:1:1 ratio (20 mg/mL each), applied directly to psoriatic lesions twice daily throughout the study period. No dose titration will be performed.
Federal University of Latin American Integration
Foz do Iguaçu, Paraná, Brazil
Psoriasis Area and Severity Index (PASI) total score
Single aggregated composite score evaluating overall psoriasis severity across four body regions (head, trunk, upper limbs, and lower limbs) and three lesion characteristics (erythema, induration, and desquamation). Individual parameters and sub-scores are combined via the standard PASI mathematical formula to yield a single reported outcome value ranging from 0 to 72, where higher scores represent greater overall disease severity.
Time frame: Baseline and 6 months
Dermatology Life Quality Index (DLQI) total score
Single aggregated score evaluating health-related quality of life using the 10-item DLQI questionnaire. Items covering symptoms, daily activities, leisure, work/school, personal relationships, and treatment (each scored 0 to 3) are summed to arrive at one reported outcome value ranging from 0 to 30, where higher scores reflect poorer quality of life.
Time frame: Baseline and 6 months
Beck Anxiety Inventory (BAI) total score
Single aggregated score evaluating anxiety symptom severity over the past two weeks using the 21-item BAI questionnaire. Individual item scores (ranging from 0 to 3) are summed to arrive at one reported outcome value ranging from 0 to 63, where higher total scores indicate greater severity of anxiety.
Time frame: Baseline and 6 months
Beck Depression Inventory (BDI-II) total score
Single aggregated score evaluating the severity of depressive symptoms over the past two weeks using the 21-item BDI-II questionnaire. Participant responses to each item (scored 0 to 3) are summed to arrive at one reported outcome value ranging from 0 to 63, where higher total scores indicate greater severity of depressive symptoms.
Time frame: Baseline and 6 months
UKU Side Effect Rating Scale total score
Single aggregated score evaluating the cumulative burden of adverse effects using the UKU Side Effect Rating Scale. Individual item scores across evaluated domains (each scored 0 = none to 3 = severe) are summed to arrive at one reported outcome value, where higher total scores indicate a greater overall severity and frequency of adverse effects
Time frame: Baseline and 6 months
Psoriasis Disability Index (PDI) total score
Single aggregated score evaluating functional disability caused by psoriasis using the 15-item PDI questionnaire. Individual item scores across daily activities, leisure, work/school, and personal relationships (each scored 0 to 3) are summed to arrive at one reported outcome value ranging from 0 to 45, where higher total scores indicate a greater degree of functional disability.
Time frame: Baseline and 6 months
Visual Analog Scale (VAS) score
Single continuous score evaluating pruritus (itching) intensity over the preceding period using a 10 cm Visual Analog Scale (VAS). Participants mark a point on a horizontal line ranging from 0 cm ("no itching") to 10 cm ("unbearable itching"). The outcome reported is the measured distance along the line in centimeters, where higher values represent greater pruritus severity.
Time frame: Baseline and 6 months
Perceived Stress Scale (PSS) total score
Single aggregated score evaluating the degree to which life situations are perceived as stressful using the 14-item PSS-14 questionnaire. After reverse-scoring positive items, all individual 5-point Likert scale items (scored 0 = never to 4 = always) are summed to arrive at one reported outcome value ranging from 0 to 56, where higher total scores indicate greater overall perceived stress.
Time frame: Baseline and 6 months
Topical Cream Overall Acceptability Score
Single aggregated score evaluating participant satisfaction and sensory characteristics (texture, spreadability, absorption, residual oiliness, odor, and skin feel) of the topical cream. Participant ratings across all 5-point Likert items (ranging from 1 = "very unpleasant" to 5 = "very pleasant") are averaged to yield a single reported outcome value, where higher scores represent greater product acceptability.
Time frame: Baseline and 6 months
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