What is phototherapy and how does it work?
Phototherapy, also known as light therapy, is essentially using light for a therapeutic effect.
It’s been used worldwide for many fields of medicine including dermatology, neonatology among others. The phototherapy units, in dermatology specifically, are useful because they generate a direct focus of designated wavelengths of light in very specific doses proven to be helpful in patients with various skin disorders.
Skin disorders and light therapy
We use phototherapy in dermatological conditions such as psoriasis, eczema, vitiligo, certain cutaneous lymphomas, like CTCL, sclerosing disorders, and even for chronic itching to name a few.
In patients with limited skin disease, for example only affecting the knees, we may suggest applying topical creams directly to the affected areas.
When skin conditions become more widespread, it's very laborious to put multiple different creams on, all over the body, once or even twice a day.
When skin diseases are moderate or severe and more widespread in nature, we often consider systemic medications, such as an oral pill or injectable medications.
As with any medication, one has to consider potential side effects. While potential side effects have to be considered with phototherapy as well, we might choose phototherapy as an option prior to moving towards some of the other systemic therapies.
We can also add phototherapy for patients who are on other medications, who might not be getting the desired response in an effort to boost their response. We may add phototherapy for patients in an effort to lower their dose of systemic medications.
Many patients also come in requesting a steroid-free option. This is another area where phototherapy might play a valuable role.
Phototherapy in dermatology is categorized it into different subtypes. The phototherapy prescribed by dermatologists include UVB, PUVA, which is also called photochemotherapy, and UVA-1.
Many professional organizations such as the American Academy of Dermatology (AAD), the Center for Disease Control (CDC), the Federal Drug Agency (FDA), The National Psoriasis Foundation do not condone the use of tanning beds for treatment of skin disease
UVB has probably been the one that we use most commonly in dermatology for skin conditions like psoriasis and eczema. There are two types of UVB - broadband and narrowband. Narrowband means the spectrum being exposed to the skin filters out everything other than the short span of wavelength, the 311 to 313 nanometer range, which has proven effective for skin disease.
Being able to expose the skin to the most effective wavelength is helpful to lessen potential side effects we know ultraviolet radiation can cause. There is also a laser, called the Excimer laser, that emits a high-intensity narrowband UVB wavelengths and has been approved for the treatment of chronic and localized psoriasis.
PUVA, also called photochemotherapy is another form of light therapy we can prescribe for patients. Patients can either prep their skin by bathing in a medicated bath, apply a cream or gel, or even take an oral medication, called psoralen, all of which enhance the effects of the light therapy.
Additional light sources are sunlight and tanning beds. We know that UVB works best for psoriasis, and although sunlight has both UVB and UVA, we don't typically recommend sunlight as a treatment option. Many factors come into play when being in the sun such as cloud cover, different regions, different genetic characteristics that determine how sensitive they might be to the sun, medications they might be on causing sensitivity to the sun etc.
Here are the tips for safe sunbathing, by the way.
Some people visit tanning beds at commercial salons as an alternative to help treat their skin conditions.
Tanning beds emit mostly UVA rays and ultraviolet radiation, particularly from these devices can damage the skin, cause premature aging, and increase the risk of skin cancer. Many professional organizations such as the American Academy of Dermatology (AAD), the Center for Disease Control (CDC), the Federal Drug Agency (FDA), The National Psoriasis Foundation do not condone the use of tanning beds for treatment of skin disease.
Exposure using these sources is unpredictable, there is a lack of a focused and effective wavelength and the doses and timing are not managed appropriately.
Are there any options to take phototherapy home?
Yes, there are options to do the treatments in the privacy at your own home.
Most patients being prescribed phototherapy will start therapy with the physician to initiate therapy and monitor closely.
Once stable and maintenance therapy begins home units are available which makes it very convenient and economical for patients. Physicians will write a prescription for the type of device best for the patient for example a panel for set up in the home or small hand held wands or small boxes appropriate for skin disease limited to just the hands and feet.
Regularly schedule follow ups are still important to monitor disease process.
Can phototherapy be applied to pregnant women and children?
The narrowband UVB phototherapy is a valid option for pregnant women and children with moderate to severe skin disease.
Does phototherapy work for depression?
Although, this is not my area of expertise, I'm aware that light therapy has been proven helpful for depression, particularly seasonal affective disorder. It has also been used in depression, jet lag, certain sleep disorders and even dementia, but additional studies are needed to determine its utility in these areas.