You may have noticed that certain prescription medicines that you get filled at the pharmacy or through a mail order pharmacy have warning labels on the container. One of the labels may warn you to avoid extended or excessive exposure to ultraviolet (UV) sunlight and/or artificial light (tanning bed) while you take the medicine. This is because the medicine may cause you to be photosensitive, or more sensitive to the sun.
Some medicines will put you at greater risk of have a bad reaction even if you are not in the sun for a long time. Your skin may burn very easily. Over time, this can cause severe skin damage and may lead to skin cancer.
There are two types of photosensitivity:
A photoallergic reaction is a rare condition. It is basically an allergy to sunlight. However, certain medicines and other products that are applied directly to the skin can cause a photoallergic reaction. You may develop an itchy, red rash; blisters; or red bumps especially in areas where the medicine or product was applied. The reaction can take one to three days to appear.
A phototoxic reaction is more common than a photoallergic reaction. This type of reaction occurs when the medicine you are taking is activated by the sun. The medicine could be a tablet, capsule, or topical cream. Some skin care products can also cause this phototoxic reaction. Once activated, the reaction can occur within minutes or hours after sun exposure. It appears as a severe sunburn or rash on areas of the skin that were exposed to the sun.
34-year-old woman with severe redness, pain, and peeling of her face, shoulders, and arms visited an emergency department. She had spent several hours at an outdoor flea market and developed the worst case of sunburn she had ever suffered.
Three weeks earlier, she had started taking Rheumatrex (methotrexate), a medicine used to treat rheumatoid arthritis. Rheumatrex is a medicine that is known to cause photosensitivity.
Ask your doctor, nurse, or pharmacist if any medicines you are taking can cause a skin reaction when exposed to the sun. Many times, your pharmacist will apply a special warning label on your prescription bottle to let you know whether or not to avoid the sun.
If you are taking a medicine that may cause a skin reaction to the sun, avoid tanning beds/booths and direct sunlight, especially between 10 am and 3 pm. When you go outdoors, use a UV-A and UV-B combination sunscreen with at least a sun protection factor (SPF) of 15.
Wear protective clothing, such as a hat and sunglasses whenever possible. If a mild reaction occurs, apply an over-the-counter (OTC) hydrocortisone cream or place cool wet bandages or clean cloths over the area to help reduce pain and itching.
Call your doctor for more severe or worsening cases. Your doctor also might be able to switch you to a different medicine that does not cause photosensitivity.
