Effect of Thymoquinone Extracted From Nigella Sativa in the Treatment of Arsenical Keratosis

Inclusion Criteria: * Age: 19 - 65 years * Arsenical keratosis: Presence of moderate to severe keratosis (\>5 mm) in both palms or soles * Drinking arsenic-contaminated water (\>50 µg/ L) for at least more than six months * Patient did not receive topical application of any drug for the last three months * Patient agreed to participate voluntarily * Patient who understood the instruction of applying drug and could apply drug as per an instruction Exclusion Criteria: * Age \<19 and \>65 years * Pregnant and nursing mother * Patient who received any treatment of arsenicosis within the last three months * Patient with skin diseases like atopic dermatitis, eczema, and psoriasis * Any systemic disease, inflammatory disease and infectious condition that affected the skin, for example, diabetes mellitus, rheumatoid arthritis, systemic lupus erythematosus and hepatitis * Food allergy to Nigella sativa