['pruritus', 'psoriasis vulgaris']
['sna-120', 'vehicle']

        Inclusion Criteria:

          -  Informed consent/assent and Health Insurance Portability and Accountability Act
             (HIPAA) authorization

          -  Stable PV for at least 6 months prior to screening

          -  Chronic pruritus of the PV plaques to be present for at least 6 weeks prior to
             screening

          -  Mild to moderate PV at screening and baseline

          -  Has a target plaque at baseline on the trunk and/or limbs

          -  Subject's plaques are amenable to treatment with a topical ointment medication

          -  Willing and able to comply with the study instructions and attend all scheduled study
             visits.

          -  Willing to avoid prolonged exposure of the designated treatment plaques to ultraviolet
             radiation

          -  Females of childbearing potential must have a negative pregnancy test at baseline
             before randomization and must agree to use highly effective contraception during the
             study

          -  Men who are sexually active and can father children must agree to use highly effective
             forms of contraception during the study

        Exclusion Criteria:

          -  Underlying conditions other than psoriasis that, in the opinion of the investigator,
             currently cause or influence pruritus of the overall skin

          -  Positive hepatitis serology

          -  Thyroid abnormalities that may impact itching

          -  Subjects with spontaneously improving or rapidly deteriorating PV and/or pruritus

          -  Current diagnosis of guttate, erythrodermic, exfoliative, or pustular psoriasis

          -  Active psoriasis or itch affecting the palmar/plantar regions

          -  Subjects with a clinical diagnosis of bacterial infection of the skin

          -  Any major medical illness or symptoms of a clinically significant illness that may
             influence the study outcome

          -  Any acute chronic medical or psychiatric condition or laboratory abnormality that
             would make them unsuitable for participation in this study

          -  Known hypersensitivity to the study treatment excipients and /or polyethylene glycol,
             that contraindicates participation

          -  Currently enrolled in an investigational drug or device study or has used an
             investigational drug or an investigational device treatment within 30 days of
             randomization/baseline (Note: Subjects who are enrolled in a long-term follow-up study
             and are not actively receiving an investigational drug or investigational device
             treatment may be eligible for participation in this study)

          -  Female who is pregnant or lactating, or is planning to become pregnant during the
             study

          -  Subjects participating in any previous SNA-120 (and/or CT327) clinical studies
      