ActinicKeratosesNet Spotlight Article
of Newer Treatment Options for Actinic Keratoses (AKs)
Imiquimod and photodynamic therapy
(PDT), two newer treatment options approved by the U.S. Food and
Drug Administration (FDA) for treating actinic keratoses (AKs),
offer patients some unique benefits. Here is what published articles
in medical journals are reporting:
Approved in 2004 for treating AKs, dermatologists prescribe this
cream to patients with multiple AKs. Meant for at-home use, patients
apply imiquimod to affected skin as directed, typically a few times
per week for a number of weeks or months.
What makes this cream so unique is that it stimulates the patient’s
own immune system to attack the cells damaged by ultraviolet (UV)
rays. As imiquimod works, it causes a brisk inflammatory reaction in
most patients. Redness, swelling, and scabbing are common. This
reaction means it is working.
As dermatologists continue to look at the safety and effectiveness
of imiquimod, they have discovered that patients may experience:
Less irritation. While
imiquimod produces an inflammatory reaction, it is typically
less intense and less painful than the reaction caused by
5-fluorouracil (5-FU), a topical chemotherapy often prescribed
in the United States to treat multiple AKs.
Fewer cosmetic side effects.
While effective, older treatment options for AKs can cause skin
discoloration or scarring. Cosmetic side effects are less
frequently reported in patients using imiquimod. Skin
discoloration (in the form of white spots developing after the
scabs disappear) has been reported.
Improved skin quality and
texture. Patients often report these welcomed effects after
using imiquimod to treat AKs. Imiquimod may partially reverse
some of the damage caused by long-term exposure to UV rays,
leading to improved skin.
Prolonged clearance of AKs and
reduction of new AKs. Once a patient develops multiple AKs,
the patient typically sees new AKs for life. As imiquimod
stimulates the patient’s immune system, imiquimod may create a
type of “memory” in the patient’s immune system that makes AKs
less likely to return. It also may reduce the incidence of new
Decreased risk of squamous cell
carcinoma. This “memory” created in the patient’s immune
system also may reduce the risk of developing squamous cell
carcinoma (SCC). AKs have the potential to progress to SCC, a
type of skin cancer that can spread. One study found that 2
years after treatment, none of the 25 patients in the study
developed SCC in the area treated with imiquimod. Of the 11
patients in this study who were treated with an inactive cream,
9 developed new AKs and 1 patient developed SCC in the treatment
It is important to keep in mind that
imiquimod is not an appropriate treatment option for every patient
with AKs. It is not meant to treat a single AK. If a patient has a
compromised immune system, imiquimod will not be prescribed. Causes
of a compromised immune system include HIV/AIDS or taking medication
to prevent organ rejection after a transplant operation. Imiquimod
also may be inappropriate for patients who work outdoors. When
exposed to UV rays, imiquimod can cause a phototoxic reaction.
Photodynamic Therapy (PDT)
Used to treat widespread or multiple AKs, PDT can be performed in a
dermatologist’s office. During this two-step process, a chemical
solution is first applied to the skin affected by AKs. This makes
the skin more reactive to light. After a prescribed time, which may
be a few hours to overnight, the treated skin is exposed to light
therapy. This brief exposure destroys AKs. While exposed to the
light, the skin may burn. After therapy, the treated area may be
painful for a brief time, showing redness, swelling, and crusting.
As more patients have received this treatment for AKs,
dermatologists have observed the following benefits:
May be as effective as 5-FU.
5-FU has long been used to effectively treat widespread AKs.
Prescribed for at-home use, patients apply 5-FU for several
weeks. Some patients discontinue 5-FU before the prescribed time
due to severe redness, swelling, and pain.
A study comparing the effectiveness of 5-FU with PDT found that
the reduction in AKs was about the same. After six months of
follow-up, the patients treated with 5-FU experienced a 70%
reduction in AKs, and the patients treated with PDT had a 73%
reduction in AKs.
Reduced treatment time.
While most therapies used to treat widespread AKs require the
patient to apply a medication at home for a period of weeks or
see a dermatologist for several treatment sessions, one PDT
session can be completed in less than 24 hours. Some patients
require 2 PDT treatment sessions.
May reduce risk of nonmelanoma
skin cancer and AKs in high-risk patients. Some people have
an extremely high risk of developing skin cancer.
Organ-transplant recipients take medication to prevent organ
rejection. This medication suppresses the immune system, which
dramatically increases the risk of developing skin cancer.
People living with Gorlin’s syndrome, an inherited condition
also known as basal cell nevus syndrome, often develop numerous
basal cell skin cancers before they reach 30 years of age. For
these and other high-risk patients, PDT may substantially reduce
their risk, according to preliminary studies. More research is
Better cosmetic outcome than
some therapies used to treat widespread AKs. During studies
conducted to determine if the FDA would approve PDT for the
treatment of AKs, patients were asked to rate the cosmetic
effects of PDT. More than 90% rated the results as “excellent”
or “good.” Studies also show that there is little risk of
scarring or skin discoloration.
Younger-looking skin. Some
light sources and lasers used during PDT for AKs also are used
to give patients younger-looking skin. When such a light source
or laser is used to treat AKs, patients tend to see a
younger-looking complexion. Reports of a decrease in wrinkles,
improved skin texture, and reduced pore size are common.
While PDT offers patients a high cure
rate and patients like the cosmetic outcome, this treatment option
is not suitable for all patients with AKs. Patients who have a
medical condition that causes sensitivity to light, such as lupus or
porphyria, are not candidates for PDT.
Lifetime Checkups Crucial
No matter how effective the treatment, patients who develop AKs
should receive regular checkups from a dermatologist for life. Most
patients will develop more AKs. Those with extensive skin damage may
see new AKs every year. For this reason, it is important that
patients diagnosed with AKs also perform regular skin self-exams and
constantly protect their skin from the sun. All recommendations are
vital in long-term management of AKs.
Braathen LR et al. “Guidelines on the use of photodynamic therapy
for nonmelanoma skin cancer: An international consensus.” Journal
of the American Academy of Dermatology. 2007. Jan;56(1):125-143.
Del Rosso JQ. “The Use of Topical Imiquimod for the Treatment of
Actinic Keratoses: A Status Report.” Cutis. 2005.
Jorizzo JL. “Matching Patients with Therapy.” Cutis.
Lebwohl M et al. “Imiquimod 5% cream for the treatment of actinic
keratosis: results from two phase III, randomized, double-blind,
parallel group, vehicle-controlled trials.” Journal of the
American Academy of Dermatology. 2004. May;50(5):714-721
Tutrone WD et al. “Topical Therapy for Actinic Keratoses, I:
5-Fluorouracil and Imiquimod.” Cutis. 2003.
Spencer JM et al. “Actinic Keratosis.” eMedicine. Last
updated October 2, 2006. Available at
http://www.emedicine.com/derm/topic9.htm. Last accessed May 31,
Yu TC et al. “Actinic Keratoses—Surgical and Physical Therapeutic
Modalities.” Cutis. 2003. May;71(5):381-384.
All content solely developed by the American Academy of
For information about the
treatments approved by the U.S. Food and Drug
Administration (FDA) for treating actinic keratoses
(AKs), visit Treatment