Purity: Wudu When a Covered Wound Can Be Uncovered
Practical Laws of Islam as per the teachings of Ayatullah Sistani
Ruling 326:
If a boil, wound, or broken bone is covered, and uncovering it is possible without causing excessive difficulty, and water is not harmful for the person, then he must uncover it and perform wuḍūʾ, irrespective of whether the wound and suchlike is on the face, arms, the front part of the head, or the feet.
-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)