The Prophet who was tested with a skin disease was Prophet Ayyub (Job). He is mentioned in both the Quran and the Bible. Ayyub was a righteous and devoted servant of God who was blessed with wealth and a family. However, God tested him with a severe skin disease that caused him immense pain and suffering. Ayyub endured this hardship with patience and faith, never questioning God's will. His story serves as a reminder that even the most devoted believers can face trials and tribulations, and that true faith lies in enduring them with patience and perseverance.