10 Medications That Cause Photosensitivity
Did you know that certain medications can make your skin more sensitive to sunlight? You may be surprised at the prescriptions mentioned because they’re quite common. Following are 10 medications that cause photosensitivity. Be aware that the chemicals within the drugs undergo changes when exposed to the sun.
What Is Photosensitivity?
Also, referred to as sun allergy, photosensitivity is the result of an immune system reaction that takes place in skin that has been exposed to the sun. Although, the exact mechanism is undetermined regarding these reactions, it is supposed that the immune system recognizes certain components of the skin as foreign or non-self.
When this happens, the body activates an immune response as a defense mechanism. This defense us what produces the symptoms, such as inflammation, redness, and swelling. Other symptoms include, red rashes, small blisters, hives in severe cases, or itchy eruptions following exposure to sunlight.
These reactions, although annoying and uncomfortable, are usually self-resolving and don’t require treatment. The areas of the body most commonly affected are the neck and upper chest, the arms and lower legs, the forehead, nose, and lips, and the backs of the hands. Reactions can be triggered by brief moments in the sun, and commonly present within 24 hours of exposure, but may take several days of continuous sun exposure to manifest.
UVA And UVB Radiation
Certain people are more prone to photosensitivity than others. Wavelengths that fall within the 320-400 nm range (UVA radiation) are more apt to initiate drug-induced photosensitivity reactions. To a lesser degree, UVB radiation, in the 290-320 nm range, can also cause reactions on the skin. This is the type of sunlight that is responsible for sunburn, and nonmelanoma skin cancer, such as basal cell carcinoma.
UVA radiation penetrates deeply into the dermis of the skin, causing photoaging, genetic damage to cells, and immune-suppression. It’s important to protect yourself from both types of radiation, because if the skin can’t repair the damage caused by sunlight, cells within the skin can start to divide and multiply uncontrollably. This is how tumor formation develops.
There are two types of photosensitivity; phototoxicity and photoallergy. Phototoxicity is a chemically-induced irritation of the skin following exposure to sunlight that does not involve the immune system. It stimulates a reaction that looks like an exaggerated sunburn, which is caused by a chemical, either entering the skin topically, or reaching the skin systemically by taking an oral medication.
Chemicals in medications absorb light from the sun, which changes their molecular structure, making them toxic. Fluoroquinolones and tetracyclines are two such drugs that produce phototoxic effects, which is more common than photoallergy. Surface contact with these chemicals, however, can cause photodermatitis or photoallergy, also referred to as sun poisoning.
In cases of phototoxicity, reactions are primarily contained within areas of the skin that have been exposed to sunlight, and usually clear once the drug is stopped. Phototoxicity is mainly associated with UVA radiation, but UVB radiation may also contribute.
Photoallergy, or sun allergy, refers to a variety of conditions that manifest as a red, itchy rash on skin that has been exposed to sunlight. Polymorphic light eruption is the most common type of sun allergy. The condition can have a genetic component or be caused by medications, particularly drugs that are used topically.
Negative reactions occur from exposure to UV radiation, which alters the structure of the chemicals in the medication. The immune system views these altered chemicals as antigens. This causes an allergic reaction within the skin that produces the symptoms, which unlike phototoxicity, can spread to areas that haven’t been exposed to sunlight.
Mild cases of photoallergy often resolve without treatment, with more severe cases being treated with steroid pills or creams. Photoallergic reactions can resemble eczema and may be chronic. The symptoms of phototoxicity generally resolve after the drug has been discontinued, whereas, photoallergy can persist even after the drug is no longer in the system.
- Small bumps and rashes
- Raised patches
- Swelling and inflammation
- Itching and redness
- Darkening of the skin
- Stinging and burning sensations
Medications That Cause Photosensitivity
Following the medications listed under each category, I will include whether the drugs are phototoxic, photoallergic, or both.
Tetracyclines, including tetracycline and doxycycline / Phototoxic
Fluoroquinolones, including Cipro and Bactrim / Phototoxic
2. Hypoglycemics (Diabetic Drugs)
Sulfonylureas, including glipizide and glyburide / Photoallergic
Ibuprofen (Advil and Motrin) / Phototoxic
Naproxen (Aleve) / Phototoxic
Ketoprofen / Phototoxic and photoallergic
Celecoxib / Photoallergic
Hydro-chlorothiazide / Phototoxic
Furosemide (Lasix) / Phototoxic
5. HMG-CoA Reductase Inhibitors
Statins, including fluvastatin, pravastatin, simvastatin, lovastatin, and atorvastatin / Phototoxic
Itraconazole / Phototoxic and photoallergic
Voriconazole / Phototoxic
7. Neuroleptic Drugs (Antipsychotics)
Phenothiazines, including chlorpromazine, fluphenazine, perazine, perphenazine, thioridazine / Phototoxic and photoallergic
Isotretinoin (Accutane) / Phototoxic
Acitretin (Used for psoriasis) / Phototoxic
9. Chemotherapy Drugs
Methotrexate, oncovir, adriamycin, gemzar, and 5-FU / Phototoxic
10. Cardiac Medications
Diltiazem, amiodarone, quinidine, and procardia / Phototoxic
Drug-induced sun sensitivity occurs when chemicals within medications are exposed to sunlight, producing unwanted effects on the skin. Reactions can result from both oral ingestion of a drug or from compounds that are using topically. If you’re on medications that increase photosensitivity, be diligent in protecting yourself when outside. Cover up and be diligent in wearing sunscreen. I keep a wide-brimmed hat in my car, and I can’t tell you how many times I’ve used it!
Are you on any medications that cause photosensitivity? Have you noticed that your skin is more sensitive to the sun? Let me know in the comments:)
(1) Merck Manual: Photosensitivity Reactions
(2) Drugs.com: Sun Allergy (Photosensitivity)
(3) Medscape: Drug-Induced Photosensitivity
(4) Cancer Council: How ultraviolet (UV) radiation causes skin cancer
(5) PubMed: Phototoxicity and photoallergy
(6) Mayo Clinic: Sun allergy
(7) MedicineNet: Sun-Sensitive Drugs (Photosensitivity to Drugs)
(8) verywellhealth: Sun Sensitivity During Chemotherapy