If you have an inflammatory skin condition, your dermatologist may recommend phototherapy.  The following are answers to some questions that are frequently asked about this treatment.

What is Phototherapy?

Phototherapy involves the medical administration of ultraviolet light.  There are three types of phototherapy treatments currently available in Canada:  Narrowband Ultraviolet B (NBUVB), Broadband Ultraviolet B (BBUVB) and PUVA (Psoralen plus Ultraviolet A).  Of these, the most commonly used is Narrowband UVB (NBUVB).  This involves the administration of a narrow part of the UVB (ultraviolet B) spectrum of light.  Narrowband machines emit a narrow range of light wavelengths which have been shown to be most effective part of the ultraviolet light spectrum in treating psoriasis.

Phototherapy is administered 2-5 times per week.  Usually a minimum of two months of treatments are required.  Each treatment lasts seconds to minutes.

How does Phototherapy Work?

Phototherapy primarily works by calming down the skin's immune system.   The skin's immune system drives the rashes and itch seen in psoriasis and eczema, and a quieting of that immune system can be highly effective in temporarily abating these conditions.  UV therapy also decreases rapid cell turnover which plays a role in the development of psoriasis.

What Dermatologic Conditions is Phototherapy Used For?

Phototherapy is used for a number of skin conditions.  These include:

Where can I go to get Phototherapy Treatments?

There are a few hospitals and private practices in Toronto that offer phototherapy.  These include the Phototherapy Education and Research Centre (PERC) at Women's College Hospital, and the dermatology department of the Toronto Western Hospital.  Your dermatologist can inform you of the phototherapy locations near you.

Will Phototherapy Cure my Skin Condition?

No.  Phototherapy is generally not curative.  Chronic skin conditions tend to recur and maintenance treatments may be required.

Can I use Tanning Beds Instead of Having Phototherapy Treatments?

The use of tanning beds is not recommended.  Tanning beds are not the same as medical phototherapy units.  Tanning beds primarily emit ultraviolet A (UVA) whereas most phototherapy units in use emit ultraviolet B (UVB).  This is because UVB is the most effective part of the spectrum for treating most skin diseases.  

Tanning beds are not regulated and the dose of light you would receive is unknown.  Their safety has frequently been called in to question on many occasions.  While it may be more convenient, visiting a tanning salon in order to treat your skin condition is not advisable.

Does Phototherapy Cause Skin Cancer?

  • Ultraviolet light is a known carcinogen and theoretically, ultraviolet light treatments might lead to skin cancer.  This has been studied extensively.  Large studies have been unable to find a link between medical UVB treatments and skin cancer.  There may be an increased risk that is borne out in future studies.  
  • In theory, narrowband UVB treatments should be less likely to lead to skin cancer than broadband UVB, PUVA, or radiation from the sun, because only a small part of the ultraviolet spectrum is administered.  These wavelengths are less energetic and are thought to be less likely to damage DNA.
  • PUVA treatments are associated with an increased risk of squamous cell carcionoma.  This risk increases with increasing numbers of treatments.
  • One study has shown an increase risk of melanoma with many PUVA treatments.  Other studies have been unable to demonstrate a link between PUVA and melanoma.

Where can I get More Information?

If you are a candidate for phototherapy, your dermatologist can refer you to one of the centres that offers this treatment.  They can discuss the risks and benefits of these treatment with you.