Patient education: Phototherapy (The Basics)

What is phototherapy? — Phototherapy is a treatment that uses a kind of light called "ultraviolet," or "UV," light. It is also called "light therapy."

In the natural world, UV light comes from the sun. But there are also special light bulbs that give off UV light. These look like tubes. Two types of UV light, UVA and UVB, are used for phototherapy.

Phototherapy can be used to treat certain skin conditions. Examples include psoriasis, eczema, and vitiligo. Doctors usually try other treatments before recommending phototherapy.

There are many types of phototherapy. They include:

●Narrowband UVB – This uses UVB light. It works for areas of skin that have skin folds.

●UVA1 – This uses UVA light.

●PUVA – This stands for "psoralen plus ultraviolet A." It uses UVA light, plus a medicine called psoralen. You take the psoralen as a pill, and then you have phototherapy on the skin. PUVA is sometimes called "photochemotherapy."

●Laser – "Excimer lasers" use UVB light and are commonly used for phototherapy. They are used to treat a small area of skin. This is called "targeted phototherapy." Other types of lasers use UVA light, or both UVA and UVB.

The type of phototherapy you have, and how often you need it, depends on your condition.

How do I prepare for phototherapy? — The doctor or nurse will tell you if you need to do anything special to prepare.

Before phototherapy, your doctor will do an exam. They might send you to get tests, such as:

●An eye exam

●Phototesting – This is a way figure out your skin's "phototype." It is based on how sensitive your skin is to the sun. This helps your doctor decide how much UV light you should get for phototherapy. It is important not to tan or sunbathe for 6 weeks before your phototest.

Your doctor will also ask you about your "health history." This involves asking you questions about any health problems you have or had in the past, past surgeries, and any medicines you take.

You will also get information about:

●If you need to take any medicines before your appointment – For example, for PUVA, you will need to take a pill before your appointment. Or you might need to use a special cream or ointment on your skin. Your doctor or nurse will tell you if you need to do this, and when.

On the day of your appointment:

●Apply sunscreen – Unless your face is one of the areas getting phototherapy, you should apply sunscreen to it before your appointment. You should also apply sunscreen to your areolas (the skin around your nipples) if your chest will be exposed. Use sunscreen that is SPF 50 or higher.

●Males should wear underwear or an athletic supporter (jockstrap). This is to protect the genitals during phototherapy.

What happens during phototherapy? — When it is time for your treatment:

●The doctor or nurse will give you special glasses or goggles to wear – These protect your eyes from the UV light.

●You will remove your clothing – Your doctor or nurse will tell you exactly what you need to remove. In many cases, you will remove all of your clothing, or all but your underwear.

●You will be exposed to the phototherapy light – Usually, this is for just a few minutes.

•In most cases, you will step into a light box – This is a box that is big enough to stand in, with lightbulbs all around.

•In some cases, you might use a smaller light unit. For example, if only your hands need treatment, you might be able to place just your hands inside a smaller light box.

•If you are having laser treatment, your doctor will aim the laser beam at the area being treated.

What happens after phototherapy? — After your phototherapy, you will get dressed, and can go home right away. Your doctor or nurse will tell you when you need to come back for more treatments. Ask them about this if you are not sure.

What are the risks of phototherapy? — Your doctor will talk to you about all of the possible risks and answer your questions. Possible risks include:

●Short-term side effects – These can include redness, skin darkening, itching, or dry skin.

●Increased risk of getting skin cancer

●Skin aging – Being exposed to UV light without sunscreen protection causes skin to show signs of age more quickly. Signs of aging can include wrinkles, uneven skin tone, and spots.

What else should I know? — While you are getting phototherapy:

●Limit your exposure to the sun as much as possible – Try not to spend more time in the sun than you have to. If you do go outside, you should:

•Wear sunscreen and lip balm that is SPF 50 or higher.

•Wear sunglasses, a wide-brimmed hat, long-sleeved shirt, and long pants.

•Stay under an umbrella, tree, or other shady spot.

Remember that you can get a sunburn even when the weather is cloudy, or if you are only outside for a short time. It's also important to avoid tanning beds.

●If your skin is itchy, you can:

•Use "emollient" creams or lotions – These help to sooth and hydrate the skin. You can ask your doctor or nurse to recommend a specific type of cream or lotion.

•Take an oatmeal bath.

•Ask your doctor for a prescription for medicine to help with the itching.

●Get yearly eye exams, if needed – Your doctor might recommend this if you have phototherapy for a year or longer. This is to make sure that the light isn't harming your eyes.

●Get regular skin exams – If you are having or had phototherapy, you should get your skin checked by a dermatologist (skin doctor) at least once a year.

●In some cases, you might be able to try "home phototherapy" – This involves buying a light box that is similar to what you would use at a doctor's office. If you have insurance, it might cover some of the cost. Do not buy or use a light box at home without talking to your doctor. They will give you instructions about when and how to use it.

More on this topic

Patient education: Psoriasis (The Basics)
Patient education: Eczema (atopic dermatitis) (The Basics)
Patient education: Vitiligo (The Basics)
Patient education: Sunburn (The Basics)

Patient education: Psoriasis (Beyond the Basics)
Patient education: Eczema (atopic dermatitis) (Beyond the Basics)
Patient education: Sunburn (Beyond the Basics)
Patient education: Sunburn prevention (Beyond the Basics)