Skip to Main Content

Welcome to

Together is a new resource for anyone affected by pediatric cancer - patients and their parents, family members, and friends.

Learn More


What is photopheresis?

Medical illustration of male child in hospital bed undergoing photopheresis treatment.

Photopheresis is a type of apheresis that removes white blood cells from the blood and treats them with UV light.

Photopheresis is a procedure that treats white blood cells with ultraviolet (UV) light. It can be used to help treat conditions such as graft versus host disease (GVHD).

Photopheresis is a type of apheresis, a procedure to remove a part of the blood. A machine separates the blood and removes white blood cells. The medicine methoxsalen (Uvadex®) is added to these white blood cells. The white blood cells are exposed to ultraviolet (UV) light. This activates the medicine. After white blood cells are treated, they are returned to the body with the rest of the blood. Only a small part of your child’s blood is out of the body at any time.

The UV light from photopheresis changes how white blood cells work. White blood cells are part of the body’s immune system. By treating white blood cells, photopheresis helps to regulate the body’s immune system.

What to expect during photopheresis

The night before and the day of the procedure, your child should avoid eating high-fat foods. If there is too much fat in the blood, the machine may not be able to separate the blood cells and the procedure may need to be stopped early.

The process of photopheresis can take 2 to 4 hours. Your care team will explain what to expect and answer any questions.

Your child will be in bed during the procedure. Have your child wear comfortable, loose-fitting clothing. During the procedure, your child can watch a movie, read, color, or have games or toys that can be played with in the bed.

Your care team decides the best way to access your child’s veins based on the size of their veins and the number of times they may have photopheresis treatments. The procedure is usually done with 2 lines (double needle procedure). Types of access include:

Your child’s care team may need to give your child fluids along with the blood that is returned to them. The fluid may be a saline solution. Or it may be saline mixed with albumin. Albumin is a purified blood protein. In some cases, your child may need a blood transfusion.

Your provider may give your child a medicine called heparin. It is a blood-thinning medicine. It keeps the blood from clotting in the apheresis machine.

Your care team will take steps to reduce the risk of infection. All tubes that touch the blood are sterile (free from germs) and are only used once.

An apheresis nurse will stay at the bedside to monitor for any reactions or problems.

Because your child will have tubes attached to the apheresis machine, they will not be able to leave the room once the procedure has started. Portable toilet equipment will be provided if needed.

Possible side effects of photopheresis

The side effects of photopheresis are similar to those that can happen when someone donates whole blood. Any side effects are usually mild and temporary. There is always the risk of rare or unknown side effects.

Side effects may include:

  • Nausea
  • Dizziness
  • Fainting
  • Pain or bruising at the site where the needle is placed
  • Blood loss
  • Infection
  • A lower blood cell count after the procedure. This decrease is usually small. But a blood transfusion or other therapy may be necessary.
  • A reaction to the blood products received during this exchange. Although not common, this may require that the procedure is stopped.
  • If photopheresis is stopped before it is complete, a small amount of blood may not be returned to the body.
  • Low blood pressure

Some people have a decrease in blood pressure after the procedure. This can cause your child to feel dizzy or lightheaded. If this happens, have your child sit or lie down and raise their legs slightly. Give cool liquids to drink when they feel better.

Side effects of methoxsalen

Methoxsalen makes your child’s skin much more sensitive to the sun. For at least 1 day after the photopheresis procedure take steps to protect your child’s skin and eyes.

Your child should:

  • Avoid sunlight.
  • Wear long sleeves and long pants when outside.
  • Wear UV-blocking glasses. Your care team may give you a pair.

Side effects caused by blood-thinning medicine

During photopheresis, your provider may give your child a medicine called heparin. This is a blood-thinning medicine. It keeps the blood from clotting in the machine.

Heparin may cause side effects that include:

  • Bruising easily
  • Bleeding that takes longer to stop
  • Signs of bleeding such as bloody stools, dark brown urine, or vomiting material that looks like coffee grounds
  • Constipation
  • Dizziness
  • Headaches
  • Nausea or vomiting
  • Irritation, pain, redness, or soreness at the injection site
  • Allergic reactions, such as hives, chills, and fever

When to contact your care team

Tell a member of your care team right away if your child has any of these symptoms during photopheresis:

  • Unusual sensations
  • Discomfort
  • Other side effects
  • A fever of 100.4 °F (38 °C) or higher
  • Skin redness that doesn’t go away after 1 day or gets worse

If you have questions about your child’s procedure, talk to your care team.

Key points about photopheresis

  • Photopheresis is a type of apheresis procedure to remove and treat white blood cells.
  • Photopheresis helps to treat immune conditions like graft versus host disease (GVHD).
  • During photopheresis, white blood cells are treated with medicine called methoxsalen and then exposed to UV light. The treated cells are then returned to your child.
  • During photopheresis, the care team monitors your child for any side effects of the procedure or medicines given during the procedure.
  • Protect your child’s skin from the sun for at least 1 day after photopheresis.
  • Talk to your care team about care instructions for before and after the procedure.

Reviewed: December 2023