Medicines and sun exposure

Also called drug-induced photosensitivity reaction

Some medicines may make your skin more sensitive or increase your risk of sunburn after exposure to ultraviolet light. This can cause a chemical change to the medicine present in your skin, resulting in a reaction.

Key points

  1. This is called drug-induced photosensitivity. It can happen after exposure to ultraviolet (UV) light either in natural sunlight (sunlight) or artificial light (such as a tanning booth) and can be triggered by products applied to your skin or medicines taken by mouth or injected.
  2. The symptoms of drug-induced photosensitivity vary depending on the medication and the type of reaction. They are called either phototoxic or photoallergic reactions.
  3. If you have recently started on medication and noticed that your skin is more sensitive to the sun, tell your doctor. Don't suddenly stop taking your medicine.
  4. If your doctor advises that need to keep taking your medicine, take extra care in the sun (slip, slop, slap, wrap) to protect your skin. 

What is drug-induced photosensitivity?

Some medicines may make your skin more sensitive after exposure to ultraviolet light – either natural sunlight (sunlight) or artificial light (such as a tanning booth). As your skin absorbs ultraviolet (UV) radiation this can cause a chemical change to the medicine present in your skin, resulting in a reaction. This is called a drug-induced photosensitivity reaction.

It can result in sunburn or redness and inflammation of the sun-exposed skin (also called dermatitis). Drug-induced photosensitivity can be triggered by products applied to your skin or medicines taken by mouth or injected.

What are the symptoms of drug-induced photosensitivity?

The symptoms of drug-induced photosensitivity vary depending on the medication and the type of reaction – phototoxic or photoallergic reaction.

Phototoxic reaction

This is the most common reaction and usually occurs when a medicine you’re taking (whether by mouth or applied to your skin) is activated by exposure to UV light and causes damage to the skin that can look and feel like exaggerated sunburn or a rash. Some people may blister. This can also be triggered by ingredients in skincare products.

A phototoxic reaction can happen within minutes or after hours of exposure to the sun and is usually just on the skin that has been exposed, such as your face, neck, arms, backs of hands and lower legs and feet.

Photoallergic reaction

This response is far less common and occurs when UV rays interact with the ingredients in medicines or other products applied directly to your skin. Your body produces antibodies that cause a reaction. A photoallergic reaction can leave you with a rash, blisters, red bumps or even oozing lesions 1–3 days after application and exposure to the sun. It may spread to areas of skin that are not exposed to the sun.

What medicines cause photosensitivity?

A variety of medicines have been associated with photosensitivity reaction.

Examples of medicines that can cause photosensitivity reaction
  • Antibiotics (eg, ciprofloxacin, doxycycline, levofloxacin, ofloxacin, tetracycline, trimethoprim)
  • Cancer medicines
  • Medicines for heart and blood pressure (cardiovascular medicines)
  • Decongestants
  • Antihistamines (cetirizine, loratadine)
  • Medicines to treat diabetes
  • Diuretics
  • Hormones such as the pill
  • Nonsteroidal antiinflammatory drugs (NSAIDs)
  • Psychiatric medicines
  • Retinoids such as isotretinoin

This is not a complete list. See DermNet NZ for a list of photosensitising medicines. It's important to note that not every person who uses these medicines has a reaction. If you have recently started on medication and noticed that your skin is more sensitive to the sun, talk to your doctor or pharmacist about it. 

How is drug-induced photosensitivity treated?

If you have recently started on medication and noticed that your skin is more sensitive to the sun, don't stop taking your medicine suddenly. Instead talk to your doctor or pharmacist about it. Sometimes a more suitable medicine can be found. Some medicines need to be stopped gradually, as stopping suddenly can make you feel very unwell.

See your doctor immediately if you develop flu-like symptoms, including fever with chills, nausea, headache and weakness, or if your skin blisters. This is could be a sign of a serious allergic reaction.

If it's not possible to stop taking the medicine, the following advice is recommended.

  • Slip on a shirt/top with long sleeves and a collar.
  • Slip into the shade.
  • Slop on sunscreen that is at least SPF 30, broad spectrum and water resistant. Apply 20 minutes before going outside and reapply every 2 hours.
  • Slap on a broad-brimmed hat that shades your face, head, neck and ears.
  • Wrap on close-fitting sunglasses.
  • Don’t use sunbeds.

Read more about how to protect yourself from the sun.

References

  1. Photosensitivity reactions – the other side of summer Medsafe, NZ 2019
  2. Drug-induced photosensitivity DermNet NZ
  3. Drug-induced photosensitivity Medsafe, NZ, 2016
  4. The sun and your medicine Food & Drug Administration, US, 2015
Credits: Sandra Ponen, Pharmacist . Reviewed By: Angela Lambie, Pharmacist, Auckland Last reviewed: 12 Jan 2020