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Treatment Options
The following have been approved by the
U.S. Food and Drug Administration (FDA) for the treatment of actinic
keratoses (AKs). Each treatment has advantages and disadvantages,
and what is suitable for one patient may be less than ideal for
another. Board-certified dermatologists and dermatologic surgeons
have the medical training and experience needed to determine which
treatments are appropriate for each patient.
Chemical Peeling
A common skin rejuvenation treatment used to give skin a more
youthful appearance; chemical peeling is also effective for treating
AKs. Often used when a patient has numerous facial lesions, chemical
peeling may be combined with another AK treatment for optimal
results.
Procedure: A local anesthesia
may be given to ease discomfort. Before the chemical solution is
applied, the skin is thoroughly cleansed, and eyes and hair are
protected. Then one or more chemical solutions are applied to the
lesion(s). The chemical(s) causes the skin to blister and eventually
peel. It is common to experience discomfort, reddening, and crust
formation over peeled areas. These are relieved with medications and
moisturizers, and the side effects usually disappear in 4 to 7 days.
How it works: As the treated
skin blisters and peels, new skin forms to replace it. Chemical
peels work by removing damaged skin at superficial, medium, and deep
levels. Medium to deep-level peeling is usually required to remove
AKs.
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Advantages
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Very effective in treating AKs
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May give skin more youthful
appearance
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Side effects usually disappear in
4 to 7 days
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Disadvantages
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Visible reddening, blistering,
crust formation and peeling over treated areas that remains
for 4 to 7 days
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Discomfort
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May require local anesthesia
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Patient downtime
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Cryosurgery
The most common method for treating AKs in the United States,
cryosurgery is used for all forms of AKs. It is best suited for
treating a few lesions that are clearly defined. However, a
multi-stage treatment plan may be used when skin damage is diffuse
or lesions are obscured by other dermatologic conditions.
Procedure: The dermatologist or
dermatologic surgeon first applies a cryogenic (extremely cold)
substance, usually liquid nitrogen, to the lesion(s). Liquid
nitrogen is applied by either 1) dabbing it on with a cotton swab or
2) spraying it on with a special device. The application causes some
discomfort, but local anesthesia is usually not required. If the AKs
are very thick and scaly, they may be pretreated with a
skin-softening cream or chemical peeling agent to “thin” them before
the cryogenic substance is applied. Single or multiple lesions may
be treated during a single treatment session. Pain and stinging can
occur after the procedure.
How it works: The cryogenic
substance freezes the surface skin, causing blistering or peeling.
As the skin heals, the AK(s) is sloughed off and new skin appears in
approximately 3 to 6 weeks. A scab may form during healing.
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Advantages
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Cure rate of approximately 98%
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Research shows effective
in
removing as well as preventing recurrence
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Well tolerated by most patients
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Side effects rare
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Local anesthetic usually
not
required
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Widely available
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Economical
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Quick
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Disadvantages
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Pain during procedure
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Healing time may be slower than
with other treatment options
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May cause skin discoloration
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Scarring possible
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May require prescription
medication to protect against bacterial and viral infection
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Patient downtime
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Curettage (with and without
electrosurgery)
This is a common procedure for treating more advanced lesions and is
often used for lesions resistant to other treatments.
Procedure: First, a local
anesthesia is administered. Once it has taken affect, the
dermatologist or dermatologic surgeon uses a curet, a spoon-shaped
instrument, to scrape off AKs cells to the level of uninvolved
tissue. Scraping may be followed by electrosurgery, a procedure that
uses a pencil-shaped instrument to cut, destroy, and cauterize the
affected tissue with an electric current. Electrosurgery widens the
area to ensure all damaged tissue is removed and limits bleeding.
How it works: The entire lesion
and a portion of uninvolved tissue are physically removed.
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Advantages
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Can obtain a specimen to
determine if squamous cell carcinoma present
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Removes the entire lesion
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Complete in 1 office visit
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Disadvantages
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Dermabrasion
Effective in destroying AKs, dermabrasion is well suited for
treating extensive AKs.
Procedure: A rapidly moving
brush is used to abrade and remove the skin down to the depth
required to eliminate the AK(s). Local anesthesia is administered
before the procedure to reduce discomfort. After treatment, the
treated skin looks as if it has been badly sunburned. Several days
are required for healing. Medication can be prescribed to relieve
the pain and soreness.
How it Works: The lesion is
sanded off to trigger new skin growth.
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Advantages
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Disadvantages
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One of the more complicated
procedures
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Requires local anesthesia
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May require prescription
medication to protect against bacterial and viral infection
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May require prescription
medication to relieve pain
and soreness
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Patient downtime
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Diclofenac Sodium Gel
FDA approved in 2002 for treating AKs, this topical medication is
used to treat multiple lesions. It should not be used by women who
are pregnant or may become pregnant during treatment.
Procedure: Patients apply the
non-greasy gel to their lesions twice a day for 2 to 3 months.
During this time, the sun must be avoided. Best results are seen
about 30 days after the patient stops applying the gel. Residual
lesions may be treated with cryosurgery.
How it works: The gel destroys
the lesion and accompanying solar damage.
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Advantages
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Well tolerated
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Easy to use (patients can self
treat)
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May treat lesions that are not
clinically apparent
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Good cosmetic effects
(no
scarring or skin discoloration)
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No patient downtime
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Minimal side effects that resolve
when treatment stopped
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Appears to be as effective as
topical chemotherapy, without the burning and irritation
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May be effective in preventing
AKs; long-term research needed to determine
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Disadvantages
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Long treatment time (60 to
90
days)
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Patient must be complaint
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Potential allergic reaction
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Imiquimod
A topical medication that comes in cream form, imiquimod belongs to
a class of drugs called immunomodulators. This means the medication
stimulates the patient’s own immune system to fight disease. To be a
candidate for imiquimod therapy, a patient must be immunocompetent
(have a normal functioning immune system).
Imiquimod may be part of a treatment plan that uses combination
therapy - use of more than one treatment method. Cryosurgery, electrosurgery, or surgical removal with a scalpel may be included
in a treatment plan that includes imiquimod as may other topical
therapies.
In clinical trials conducted to gather the data needed to submit
imiquimod to the FDA for
approval, AKs on the face and scalp were treated. Nearly half of the
patients treated with imiquimod saw all of their treated lesions
clear, and the majority of patients treated with imiquimod
experienced a clearance rate of 75% or more.
While imiquimod causes skin irritation, patients participating in
clinical trials who have used other topical therapies that cause
skin irritation reported that imiquimod seems less irritating and
more tolerable.
Procedure: Patient applies the cream as directed by a
dermatologist. The course of treatment may vary from 4 to 16 weeks,
depending on several factors, including the severity of the AKs and
patient’s response. The patient is carefully monitored during
therapy to determine if the amount of cream being applied is
sufficient, or if more or less imiquimod should be used. A rest
period (treatment stopped and then resumed) may be given during
imiquimod therapy.
How it works: Imiquimod modifies the skin’s immune system,
which stimulates the body to reject the UV-damaged cells. When skin
inflammation develops, it indicates that the lesion is being
destroyed.
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Advantages
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Well tolerated
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Non-invasive
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Excellent to good cosmetic
results
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Can clear AKs not yet visible,
causing them to appear and clear
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Little scarring
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No skin discoloration
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Good option for treating face,
where may be
difficult to perform more invasive therapy
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No patient downtime
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Disadvantages
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Irritation usually develop on
treated skin - redness, flaking, and scabbing typical
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Not effective for all patients
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Patient must apply medication as
directed
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Longer treatment time
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Cost of imiquimod
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Laser Resurfacing
Less common procedure. Used to treat a few localized lesions as well
as multiple AKs. Best suited for treating AKs on the lips.
Procedure: Local anesthesia is
given, and after it takes effect, a laser is used to remove skin to
the depth needed to eradicate the AK cells. Skin redness is the
primary side effect. A week or two is needed for healing.
How it Works: The laser removes
the skin to the depth required to eliminate damaged tissue.
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Advantages
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Allows dermatologist to more
precisely control amount of tissue removed
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Can treat multiple lesions
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Good cosmetic effects
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Low risk of scarring and other
complications when treated by a physician who is skilled in
using the laser and experienced in treating AKs
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Disadvantages
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Photodynamic Therapy
One of the newer treatment methods, it is most appropriate for
treating multiple AKs on the face and scalp.
Procedure: A topical medication,
5-aminolevulinic acid (ALA), is applied and left in place for a
specified amount of time, usually between 3 and 18 hours. The area
is then treated with a blue light source.
How it works: The AK cells are
destroyed when protoporphyrin IX - a chemical that is produced when
the topical solution interacts with the skin - is exposed to the blue
light. Results may be seen as early as the first session; however,
re-treatment may be needed.
Surgical Excision
When a lesion is especially large or thick or is resistant to
treatment, surgical removal is an option.
Procedure/How it Works: The
entire lesion along with some healthy tissue are excised and sent to
a dermatopathologist, who performs a microscopic examination to
determine if cancer cells are present.
Topical Chemotherapy
The topical chemotherapy agent that is FDA approved for treatment of
AKs is 5-Fluorouracil (5-FU). It is effective in treating multiple
AKs and is one of the most frequently used AK treatments in the
United States. This method must not to be used by women who are
pregnant or may become pregnant during the course of treatment.
Procedure: Patient applies the
topical 5-FU as directed by the dermatologist or dermatologic
surgeon. A typical course of treatment requires applying
5-FU twice
daily to the AKs for 2 to 4 weeks. However, this may vary depending
on the area to be treated and the treatment’s progress. 5-FU causes
sun-damaged areas to become irritated. In fact, immediately
following application, the patient usually sees a localized red spot
that remains for some time and experiences a burning sensation
and/or itching at the site. It is critical that the patient prevent
direct sunlight from reaching the treated sites as sunlight can
cause intense pain. As treatment progresses, patients typically
notice the treated AKs begin to form crusts and erode and redness
develop.
An allergic reaction may develop, which
needs to be reported immediately
to the patient’s dermatologist or
dermatologic surgeon.
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 |
This patient
continued to use
5-FU after an allergic reaction developed.
It
eventually cleared after he stopped using the medication. |
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(Photo used with permission of the American Academy of
Dermatology National Library of Dermatologic Teaching Slides) |
How it works:
5-FU destroys AK cells by blocking essential biochemical reactions
in the cells.
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Advantages
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Disadvantages
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Requires 100% patient compliance
to be effective
(If dose missed, patient cannot
double next dose to comply.)
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Failure rate high as 60% when
patient not compliant
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Patient must endure some
unsightly and painful side effects, such as severe redness and
burning of the skin, to complete therapy
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Allergic reaction can occur,
and it may be difficult for patient to distinguish between
expected side effects and allergic reaction
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References:
AAD Guidelines of Care for Actinic Keratoses (1995).
Callen JP et al.
“Actinic keratoses.” J Amer Acad Dermatol 1997; 36:650-653.
Dinehart SM. “The
treatment of actinic keratoses.” J Amer Acad Dermatol 2000;
42:S25-S28.
Yu, TC et al. “Actinic
Keratoses—Surgical and Physical Therapeutic Modalities.” Cutis,
2003; Vol.71, No. 5:381-384.
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