Hello, A week and a half ago (2/09) I used Walgreen s antibacterial bandages that have 0.1% Benzalkonium Chloride. I used these for two days, replacing them when I felt they were getting old. I then experienced a delayed onset of irritation within 48 hours later and stopped using them. I had one patch on my forehead and one patch on my cheek, in the exact square of the medicated non-stick pad. I went to the dermatologist immediately, and she gave me Synalar to use for a week on the affected areas to reduce inflammation and Claritin to take in the morning and Benadryl and Tagamet to take at night. She diagnosed me with contact irritant dermatitis. I also use sunscreen on the areas to avoid dark spots. The patch on my forehead has successfully cleared. However, the patch on my cheek is still very noticeable. The inflammation has gone down, but there is significant discoloration and hyperpigmentation. I will be visiting my dermatologist again this week, but I am concerned that this mark will be permanent. What could be the cause of this, and why does the mark on my cheek seem permanent (I m not itchy or anything)? I m worried that the Benzalkonium chloride did permanent damage to my skin.