Local Methotrexate Injections for the Treatment of Nail Psoriasis

Inclusion Criteria: * Subject must be at least 18 years of age * Subject must have nail psoriasis that is clinically diagnosed in at least 3 fingernails Exclusion Criteria: * Subject with any clinically significant condition or situation, other than the condition being studied that, in the opinion of the investigator, would interfere with study evaluations or optimal participation in the study. This is including, but not limited to: immunodeficiency, onychomycosis, any other nail condition other than psoriasis, allergy to methotrexate, triamcinolone acetonide, local anesthetic, normal saline, or any other material used for procedures * Subject who has received radiation therapy, chemotherapy, and/or immunosuppressive drugs within 6 months of study, and/or oral corticosteroids or IV methotrexate for \>1 month within the 6 months of study (exception inhaled steroids); * Subjects who use substances (medications, supplements, ect) known to significantly interact with drugs used as intervention in the study * Subject who is pregnant, breastfeeding, or planning to get pregnant * Subject known to have received treatment with investigational drugs or devices within 30 days prior to enrollment into this study * Subject who is on systemic treatment for psoriasis * Subject with baseline abnormalities in liver function tests or complete blood count * Subjects with diagnosis of renal insufficiency or impairment * Subject who is unwilling to abstain from any cosmetic nail treatments outside those provided by the study clinic, beyond basic nail trimming (i.e. no spa nail treatments, no nail polish use, no other topical prescription nail medication) * Subject who is unwilling to abstain from any medical nail treatments on their nails other than the study intervention (i.e. topical steroids, antifungal creams) for the duration of the study intervention and for duration of the washout period (if applicable) * Subject who is part of the staff personnel directly involved with this study or a family member of the investigational study staff