Q: I have psoriasis since 8 years. Recently my doctor asked me to use white petroleum jelly and salicylic acid mixture as a medicine. I was asked to use 15% concentration. It did show good results. I want to know about this acid and if it will have any future side effects of any type? I also have a lot of dandruff. I was asked to use this in hair too but it turns out to be very messy and oily. Can you recommend me an alternative?

A:Salicylic acid is indeed useful in removing scales and is most effective when used concurrently with topical steroids, dithranol or coal tar. Side effects is not a problem even when used for long periods. For dandruff, you can use any of the popular shampoos that contain zinc and selenium. The reason for failure is that shampoo is washed off too soon and the number of applications is not adequate. For very severe form of dandruff, one can use ketaconazole-based shampoos.