What is Phototherapy?
Phototherapy is the treatment of skin diseases with light, commonly using ultraviolet (UV) light. UV light is that invisible part of sunlight with wavelengths shorter than visible light. The history of phototherapy dates as far back as ancient Egypt, where natural light was used in combination with herbal extracts to treat skin diseases.
The UV spectrum is classified into 3 wavelength ranges – UVA, UVB and UVC – in descending order of wavelengths. UVA and UVB are used in medical treatments. UVA penetrates deeper into the skin and is more often associated with skin aging. It is the most abundant form of UV rays in sunlight that reaches the earth surface. UVB is associated more with sunburns.
How does Phototherapy work ?
Phototherapy has the effect of reducing skin inflammation and promoting growth of pigment cells in the skin. Hence it is especially well suited for the treatment of vitiligo and inflammatory skin conditions like psoriasis and eczema.
What skin diseases can Phototherapy treat ?
Skin conditions that have been effectively treated with phototherapy include:
- Atopic dermatitis also commonly known as eczema
- Nodular prurigo
- Pityriasis rosea
- Pityriasis lichenoides chronica
- Lichen planus
- Chronic spontaneous urticaria
- Progressive macular hypomelanosis
How is treatment like ?
Phototherapy can be delivered either to the whole body or only to a certain part of the body. The machines used are different in each case.
Whole body phototherapy is conducted in a stand-up position inside an enclosed treatment booth. The inner walls of the treatment booth are lined with UV lamps all around for a uniform whole body treatment. This is the most common form of treatment and is suitable for skin diseases that involve a large proportion or span across different parts of the body.
Targeted phototherapy on the other hand, is delivered via a handheld UV lamp operated by a therapist. This form of phototherapy treats only the affected parts of the skin and spares normal skin from unnecessary UV radiation. It is suitable for treatment of skin diseases affecting only a small part of the body.
In whole body phototherapy, the initial treatment time is brief, usually less than a minute. This time will gradually increase in subsequent sessions as the skin becomes used to the effects of treatment such that a higher dose of UV light will be required to maintain effective treatment effects.
Treatment times for targeted phototherapy will depend on the amount of skin area to cover in one treatment session. Treatments are usually carried out 2 to 3 times per week for several weeks and sometimes several months in order to see significant improvement in the skin conditions treated.
The number of treatments needed to achieve satisfactory clearance of skin disease is variable and depends on several factors like the type of skin disease being treated, duration of disease, area of the body affected, sensitivity of the skin to UV therapy and others. Consistently following a regular treatment schedule is usually key to successful therapy.
Once satisfactory clearance of disease has been achieved, maintenance phototherapy once a week or fortnight may be recommended to prevent relapse.
Phototherapy may sometimes be combined with certain oral medication and/or topical creams to enhance treatment effects and success.
Is Phototherapy safe ?
Phototherapy is generally a very safe method of treating skin diseases. It is an externally applied treatment that does not harm the internal organs compared to certain oral medications that are used to treat skin diseases.
The actual treatment is generally painless. The most common potential side effects are sunburn, redness of the skin, itchiness and dryness that are easily relieved with frequent application of a moisuriser. Very rarely, severe sunburn can develop that requires medicated creams for treatment.
A tan may also develop after prolonged phototherapy.
The eyes and skin of the male genital organs can be susceptible to damage from UV radiation. Hence it is important to shield those areas during phototherapy with UV protective goggles and underwear. Doing so can prevent such risks.
It is possible with any form of UV light that an increased incidence of skin cancer may occur later in some patients, usually only after many UV light treatments. This risk is minimal in short-term therapy. Studies to date have not shown association of narrowband UVB phototherapy with increased skin cancer.
Skin aging is another side effect of long-term therapy.
How do I know if I am suitable for Phototherapy ?
Your doctor will ask about your medical history and the medications that you are currently taking before advising if you are a suitable candidate for phototherapy. Certain medical conditions such as systemic lupus erythematosus can be made worse by phototherapy and if you have such a medical condition, you may not be suitable for phototherapy. Certain medicines can make you more sensitive to UV light or sunburn easily. If the medicine that you are taking have this concern, then adjustment to dose or time of taking the medicine may have to be made before phototherapy.
Phototherapy is usually recommended as the next step in treatment if medicated creams are no longer working for your current skin condition.
Phototherapy is avaiable at our Vitiligo, Psoriasis & Skin Clinic, if you have any question or would like to find out more about phototherapy and how this safe and potentially beneficial treatment method can help manage your skin disease.
Next read: Vitiligo Causes, Signs & Symptoms