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Phototherapy: A
Treatment Option for Atopic Dermatitis
Phototherapy exposes
a patient to ultraviolet (UV) light for a controlled amount of time in
order to treat skin conditions, such as atopic dermatitis, seborrheic
dermatitis and psoriasis. While effective, phototherapy is not
appropriate for everyone. It is not recommended for children, patients
whose eczema flares when exposed to sunlight, or anyone who develops a
sun-induced allergic reaction.
When phototherapy is
prescribed, it is likely to be part of a total therapeutic regimen that
includes topical and/or systemic medications as well as a modified
lifestyle to prevent flare-ups.
Two types of
phototherapy are used to treat eczema:
- UV light
therapy
- Psoralen
+ UVA exposure (called PUVA or chemophototherapy)
UV light therapy may be used alone or with a topical agent, such as coal tar. Ultraviolet
A (UVA), ultraviolet B (UVB) or a combination of UVA and UVB therapy may
be used. During therapy, the patient’s skin, or just the affected area(s),
is exposed to the UV light. Goggles are worn during treatment to protect
the eyes. Patients usually receive treatment in a dermatologist’s
office.
There are 2 types of
UVB phototherapy:
-
Broadband (3-5 treatments per week)
-
Narrowband (2-3 treatments per week)
Broadband.
This UVB therapy has been around for more than 80 years, and it is still
highly effective. The biggest drawbacks are that the patient must travel
between 3 and 5 times per week to a site that offers this therapy and
that broadband light does not reach the scalp and areas where skin folds
occur.
Narrowband.
This newer
form of UVB therapy is called “narrowband” because it emits a narrower
band of UVB wavelengths. Narrowband UVB therapy is proving to be more
effective than the traditional broadband therapy. However, it does have
the potential to produce severe burning. Like broadband, it is still not
known if narrowband UVB therapy poses a long-term risk for development
of skin cancer.
PUVA
requires the patient to
ingest, topically apply or bathe in a medication called psoralen before
being exposed to UVA rays. Psoralen makes the skin more sensitive to UVA
rays. After treatment, patients must wear UVA-blocking sunglasses for
the rest of the day when exposed to sunlight because psoralen remains in
the eyes for awhile. PUVA’s effectiveness is limited to carefully
selected patients whose condition is likely to respond to PUVA. PUVA has
a number of side effects, which may include nausea, headache, fatigue,
burning skin, itching and irregular skin pigmentation.
A series of treatments
is usually needed,
and a full course of treatment may take 6 months.
Several studies have
demonstrated substantial improvements when PUVA is combined with topical
corticosteroids.
Why Phototherapy Works
UV light of certain wavelengths affects the immune system. By carefully
exposing patients to these UV wavelengths for specified amounts of time,
dermatologists are able to prevent the exaggerated immune response that
causes the inflammation.
Benefits
The beneficial effects of phototherapy vary from person to person.
Phototherapy can:
-
Significantly improve, and even clear, atopic dermatitis. One study
conducted in Germany investigated the effects of phototherapy on severe
atopic dermatitis. Investigators found more than 80% of the patients
with atopic dermatitis who were treated with phototherapy showed
significant improvement, and in some cases, complete clearance within
three weeks.
- Help
prevent bacterial infections, which are common in the skin of patients with atopic
dermatitis.
- Reduce
the strength of topical corticosteroids required, and in some cases,
eliminate the need for topical corticosteroids.
Risks
While
phototherapy can significantly improve atopic dermatitis and even
completely clear it in some cases, phototherapy does carry these risks:
- UV light
is a contributing cause of skin cancer
- UV light
has been proven to prematurely age the skin
Not for Everyone
Phototherapy does not improve everyone’s skin. In some cases, it can
make the condition worse. Board-certified dermatologists have the
medical training and experience needed to carefully weigh the risks and
benefits of phototherapy to determine if this treatment is right for a
patient. In considering whether or not phototherapy is appropriate,
dermatologists look at a number of factors, including the patient’s age,
health, medical history, severity of the condition and history of
previous treatment.
References
AAD Guidelines of Care for Atopic Dermatitis.
July 26, 2003
Von Kobyletzki G et
al. “Phototherapy in severe atopic dermatitis. Comparison between
current UVA1 therapy, UVA1 cold light and combined UVA-UVB therapy.”
Der Hautarzt 1999:
Jan; 50(1): 27-33. German.
Krutmann J.
“Therapeutic photomedicine: phototherapy.” In: Freedberg IM et al
(Eds.). Fitzpatrick’s Dermatology in General Medicine. 5th
ed. New York: McGraw-Hill; 1999:2870-2879.
More Information
Medications and Other Therapies Used to Treat Eczema
Describes the medications that dermatologists may prescribe to treat
eczema and two topical therapies, moisturizers and cold compresses,
which can be effective
Preventing Flare-Ups
Lifestyle modifications that can help prevent flare-ups, includes links
to guidelines for bathing and moisturizing, what you can do around the
home that may help bring relief, stress-reduction techniques and more
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