Evaluation of the Efficacy and Safety of Indigo Naturalis Oil Extract on Psoriatic Nails

Inclusion criteria:

1. adults aged between 20 and 65 years

2. received a diagnosis of nail psoriasis with at least one year history based onclinical assessment by two dermatologists and failure of topical systemic Chineseherbal anti-psoriasis therapy for fingernail psoriasis.

3. Female patients of childbearing age agreed to continue using birth control measuresfor the duration of the study.

Exclusion criteria:

1. Patients had non-plaque (i.e., pustular, guttate, or erythrodermic) or drug-inducedforms of psoriasis, total body surface involvement of more than 60%

2. a history of allergy to indigo naturalis, or with onychomycosis or any fingernailinfection.

3. Patients have received systemic therapy within four weeks before enrollment

4. Patients have received phototherapy within three weeks, or topical psoriasis agentswithin two weeks.

5. Using medications which affect psoriasis during the study and unwillingness to complywith study protocol.