Phototherapy is a type of medical treatment that involves exposure to fluorescent light bulbs or other sources of light like halogen lights, sunlight, and light-emitting diodes (LEDs) to treat certain medical conditions.


There are different types of phototherapy and the kind, as well as the technique used by your doctor, will depend on the condition you have that is being treated.


Phototherapy is also known as light therapy and heliotherapy.




Phototherapy has been used to treat medical conditions for as far back as 3,500 years ago when the ancient Egyptians and Indians used sunlight to treat skin conditions like vitiligo.


MODERN PHOTOTHERAPY, using artificial light sources, began with Niels Ryberg Finsen. Widely regarded as the founder of modern phototherapy, he treated a skin condition called lupus vulgaris with sunlight and ultraviolet radiation. From then on, usage of phototherapy in medical fields grew, techniques were refined and developed, and it eventually gained widespread acceptance.



Skin conditions like eczema, psoriasis, vitiligo, itchy skin, and the skin symptoms of cutaneous T-cell lymphoma can be treated using phototherapy. The phototherapy treatment involves using UV light—a kind of light present in sunlight—to reduce skin cell growth and inflammation.



There are three main types of phototherapy used for skin disorders:


Broadband UVB: Also known as BBUVB, broadband UVB involves treating skin conditions like eczema and psoriasis with the full spectrum of ultraviolet-B radiation.


Narrowband UVB: This involves using only a small portion/part of UVB radiation to treat the skin condition. It is more intense than broadband UVB and it’s the most common phototherapy option used by dermatologists.


PUVA: This stands for Psolaren ultraviolet-A. This involves combining UVA light with a certain kind of chemical called psoralen. Psolaren can be applied to your skin or you can take it as a pill. This chemical is found in plants and it makes your skin more sensitive to the light that’s to be applied. PUVA is more intensive and has more side effects than broadband or narrowband UVB, and is usually only resorted to when treatment with the others have been unsuccessful. It’s used for conditions like vitiligo, cutaneous T-cell lymphoma, and psoriasis.


The effects of phototherapy for skin disorders are usually temporary. This means it’s not a permanent treatment and you may have to undergo numerous sessions— also known as maintenance therapy— of it a couple of times over to maintain the results.


When used for skin conditions, phototherapy is generally considered safe. However, short-term side effects you may experience are redness, dry skin, itchy skin, nausea (if PUVA is used), folliculitis, and blisters. Also, there are some long-term side effects associated with it, the most serious of which are skin cancer and premature skin aging.



Phototherapy is also used to treat mood and sleep disorders, although it’s most commonly referred to as light therapy in these contexts. The major conditions it is used for are seasonal affective disorder (SAD) and circadian rhythm sleep disorders.


Seasonal Affective Disorder (SAD)

The seasonal affective disorder is also known as seasonal depression, and it is brought on by seasonal changes, usually beginning in the fall and lasting throughout winter. Light therapy for SAD involves using a lightbox—a specially designed box that emits soft light at a standard wavelength.


Light therapy used this way has a number of side effects you should be aware of. Some of them are headaches, fatigue, insomnia, hyperactivity, and irritability.


Light therapy is usually recommended for SAD because while it does have side effects, they are minimal and usually temporary, and it is an easy, relatively cheap treatment option.  Also, if it works for you, you may be able to reduce the amount of anti-depressant medication you use (if any).


Phototherapy has also been explored for non-seasonal depression. As it stands, though, while some studies support the use of light therapy and suggest it is worth exploring if you have nonseasonal depression.


Circadian Rhythm Sleep Disorders

Phototherapy can help those who have circadian rhythm sleep disorders such as DSPS (delayed sleep phase syndrome) make the shift to normal sleeping patterns and times. With this kind of treatment, the time at which it is done is extremely important. Your doctor or sleep specialist will help you determine the right time for you to be exposed to the light, after taking into consideration your individual symptoms.



A certain kind of phototherapy known as photodynamic therapy is used to treat some kind of cancer and precancers. It involves using a special type of drug, called a photosensitizer, in combination with a special kind of light. Photosensitizers produce a kind of active oxygen that, when exposed to specific light wavelengths, kills nearby cells.


The photosensitizer drug is applied topically to the body. Both normal and cancerous cells absorb the drug, but it is thought that the drug concentrates preferentially in quickly dividing cancer cells. Furthermore, normal cells clear the drug faster than cancerous cells. So, at the point when most of the photosensitizer has left the healthy cells but is still present in the cancerous ones, light is applied to the area to be treated. A reaction occurs between the light and the photosensitizer drug, creating activated oxygen inside the cancer cells.

This activated oxygen kills the cancer cells.


Photodynamic therapy is used to treat cancer like cancer of the esophagus, endobronchial cancer (non-small cell lung cancer), and precancerous conditions like Barret’s esophagus.


In addition to being simply called phototherapy, you may hear of photodynamic therapy being referred to as photoradiation therapy or photochemotherapy.


Phototherapy for treating cancers is a great option, as it has a number of advantages over treatments like radiation and chemotherapy. For one, it doesn’t generally have any long-term side effects. It is less invasive and leaves less scarring than surgery. And in general, phototherapy costs a lot less than the other treatment options for cancer.

However, its application is largely limited to places where light can reach, which is usually just below the skin, and it also can’t help much with cancers that have spread.



Phototherapy has been used for over six decades to treat hyperbilirubinemia and jaundice (the yellowing of a baby’s skin, eyes, and body tissues as a result of excess bilirubin). In this case, phototherapy is used to reduce the baby’s bilirubin levels.


Bilirubin absorbs light, which results in the breakdown of bilirubin to substances that the baby’s body can process and excrete


There are two major ways babies with jaundice are treated with phototherapy. The usual way is to cover the baby’s eyes and place them under halogen spotlights or fluorescent lamp lights.


For babies who are born preterm or have already been treated with the overhead conventional lights, “biliblankets” may be used. Also known as fibreoptic blankets, these biliblankets are laid with fiber-optic cables which shines the blue light onto the baby’s back and body.


Compact fluorescent light tubes and blue LED (light-emitting diode) devices are also used to give babies phototherapy treatment. They can be kept close to the babies’ bodies as they do not produce a lot of heat.


Phototherapy for treating hyperbilirubinemia and jaundice is considered very safe medically. However, the short-term side effects of it include diarrhea, rashes, overheating, and water loss/dehydration.


New Treatments

Currently, scientists are exploring the use of phototherapy to treat other medical conditions like diabetic retinopathy and hair loss.



Phototherapy treatments as a whole have a number of risks that should be known.


For one, ultraviolet rays can cause progressive and gradual damage to your skin on a molecular level. This premature aging of the skin is also known as photoaging.


Exposure to high amounts of artificial ultraviolet light also increases your risk of developing skin cancer. The more treatments you undergo and the fairer your skin, the higher your risk of getting skin cancers.


Frequent phototherapy treatments can also lead to immunosuppression. Basically, light therapy can suppress your immune system, leaving your body open to diseases, infections, and skin cancers too.


Further, undergoing PUVA treatments for skin or photodynamic therapy for cancer also makes your eyes more sensitive to light. If your eyes aren’t properly protected after such treatments, their sensitivity can lead to eye damage from exposure to sunlight or other bright lights, and the development of cataracts.


Who Should Avoid Phototherapy?

If you fall into any of these categories, you should avoid being treated with phototherapy, or at the very least inform your doctor or dermatologist about it in advance.


  • Being pregnant or a nursing mother
  • Having a family history of skin cancer
  • Having liver disease
  • Having lupus


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