Transcript Related Guidelines

Side Effects of Phototherapy in Patients With Psoriasis 

Henry W. Lim, MD · Henry Ford Health System


July 26, 2021

Key Takeaways:

  • Acute side effects associated with phototherapy are similar to those related to sun exposure

  • More concerning are the potential carcinogenic effects of phototherapy

  • However, adherence to clinical guidelines for the administration of phototherapy can help minimize these risks 

 This transcript has been edited for clarity.

Phototherapy can be used very, very safely. However, like any type of treatment, any type of medications, we have to be familiar with its benefit but also with the side effects. Side effects for phototherapy can be divided into two general categories. The first one is acute side effects. These are primarily very similar to sun exposure; that is, one can get sunburned, one can get tan in these patients. That is the reason when we start phototherapy, we start with low dose and gradually increase to minimize the probability of the patient getting sunburned; but you do have to tell the patients that most likely they will get tanned. 

The long-term side effect is the one that has been of concern to many: whether it would induce skin cancer. However, there are very, very good studies, very good data to indicate that the way that we deliver phototherapy for psoriasis in terms of photocarcinogenesis actually is very safe. Meaning phototherapy, the way it is delivered to treat psoriasis does not increase the rate of skin cancers in patients.[1,2] 


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.