MEDLINE Abstract Collection: Actinic Keratosis
What's new concerning our understanding of actinic keratosis? Find out in this easy-to-navigate collection of recent MEDLINE abstracts compiled by the editors at Medscape Dermatology.
Chamberlain AJ, Kurwa HA
Am J Clin Dermatol. 2003;4:149-155
Photodynamic therapy (PDT) is proposed as an effective therapy with a good safety profile for patients with actinic keratoses. PDT involves the application of a photosensitizer to dysplastic or neoplastic tissue such that when exposed to light of an appropriate wavelength, the target tissue undergoes a cytotoxic reaction. Studies to date have demonstrated that PDT for the treatment of patients with actinic keratoses achieves clearance of lesions with minimal morbidity, maintenance of functional integrity of underlying tissues, and excellent cosmetic results. We present a review of the treatment of patients with actinic keratoses and the role of PDT in this context.
Walker JK, Koenig C
J Fam Pract. 2003;52:184-185
Imiquimod 5% cream, applied 3 times per week for 12 weeks, is effective for treatment of actinic keratosis. Severe erythema and other local reactions occurred in almost everyone receiving treatment, due to imiquimod's immune system-modulating effects. The 25 patients in the treatment group tolerated these adverse effects well. Despite these effects, imiquimod can be used as an alternative to traditional cryotherapy for the treatment of actinic keratosis among selected, motivated patients.
Pariser DM, Lowe NJ, Stewart DM, et al
J Am Acad Dermatol. 2003;48:227-232
Background: Photodynamic therapy (PDT) is a promising new treatment modality for actinic keratoses. Methyl aminolevulinate (MAL) (Metvix, PhotoCure, Oslo, Norway) leads to selective accumulation of photoactive porphyrins in premalignant skin lesions and makes the lesions susceptible to phototoxic effects on illumination with red light.
Objective: This multicenter, randomized, double-blind study compared complete response rates, cosmetic outcome, and patient satisfaction for PDT with cream containing 160 mg/g MAL or placebo cream in the treatment of actinic keratoses.
Methods: After application of the cream under occlusion for 3 hours, the lesions were illuminated by noncoherent red light (570-670 nm, light dose 75 J/cm(2)). Treatment was repeated after 1 week and response was assessed 3 months later. A total of 80 patients were randomized into the study, 42 in the active and 38 in the placebo group.
Results: Complete lesion response rate was higher after MAL PDT than placebo, 89% versus 38% per protocol analysis (P =.001). An excellent or good cosmetic outcome was reported in more than 90% of patients treated with MAL.
Conclusion: In this small study, PDT using topical MAL was a safe and effective treatment for actinic keratoses with excellent cosmetic outcome. It is a promising treatment that could benefit from further study.
Nakaseko H, Kobayashi M, Akita Y, Tamada Y, Matsumoto Y
Br J Dermatol. 2003;148:122-127
Background: Photodynamic therapy (PDT), which employs a combination of a tumour-localizing photosensitizer and visible light, has been used to treat superficial malignancies in the epidermis.
Objectives: To examine histological changes and the role of apoptosis in lesions of actinic keratosis (AK) after PDT using 5-aminolaevulinic acid (ALA) and excimer dye laser.
Methods: After topical ALA-PDT, biopsy specimens were collected from 18 skin lesions in 15 patients with AK. Paraffin-embedded sections of the skin specimens were stained with haematoxylin and eosin. The detection of apoptosis was performed using a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) method, antiactivated caspase-3 antibody and anti-Fas antibody.
Results: One hour after PDT, cells with eosinophilic cytoplasm and markedly stained nuclei were found, and vacuolation of some tumour cells was noted in the lower layer of the epidermis. An infiltrate of lymphocytes and neutrophils was observed in the upper layer of the dermis. One day after PDT, all layers of the epidermis exhibited slightly degenerative necrosis, with shadow cell formation and chromatin condensation around the nuclear membrane in the lower layer of the epidermis. Necrosis in all layers of the epidermis and lymphocyte infiltration in the dermis were found 3 days after PDT. Tumour cells had disappeared and regenerative thickening of the epidermis was observed 7 days after PDT. TUNEL staining revealed apoptosis-positive cells in the epidermis in 8 of 11 specimens obtained 1 day after PDT. Activated caspase-3 expression was noted in the lower layer of the epidermis in four of these eight TUNEL-positive specimens.
Conclusions: Results suggested that apoptosis is involved in tumour cell death after PDT in patients with AK, and that it occurs within 1 day after PDT.
Jorizzo J, Stewart D, Bucko A, et al
Cutis. 2002;70:335-339
The efficacy and safety of a new 0.5% fluorouracil topical cream were compared with vehicle control for the treatment of actinic keratosis (AK). Active treatment applied once daily for 1, 2, or 4 weeks was more effective than vehicle control in achieving reduction from baseline in lesion counts and lesion clearance. Active treatment also resulted in significantly better global assessments of overall improvement. Treatment was effective regardless of the number of baseline lesions. Although longer treatment duration correlated with greater efficacy, treatment for 1, 2, or 4 weeks was effective. This new microsphere-based fluorouracil formulation was generally well tolerated; adverse events were primarily limited to facial irritation that resolved quickly after treatment. This new treatment provides a safe alternative to the topical fluorouracil formulations currently available for the 1-, 2-, or 4-week treatment of AK.
Stockfleth E, Meyer T, Benninghoff B, et al
Arch Dermatol. 2002;138:1498-1502
Background: Actinic keratoses (AKs) are precancerous epidermal lesions found most frequently on areas of the skin exposed to the sun. Several case studies published recently have indicated that 5% imiquimod cream, currently licensed for the treatment of genital warts, may be an effective treatment for AK.
Objective: To assess the efficacy and safety of imiquimod for the treatment of AK.
Design: Patients in this randomized, double-blind, vehicle-controlled study applied 5% imiquimod cream or vehicle to AK lesions 3 times per week for a maximum of 12 weeks or until lesions had resolved. In the event of an adverse reaction, application of imiquimod was reduced to 1 or 2 times per week. Rest periods were also allowed if necessary.
Setting: A specialized outpatient dermatology clinic within a state-funded hospital in Germany.
Patients: The study population was aged 45 to 85 years. Of 52 patients screened, 36 men and women with AK confirmed by histological diagnosis were enrolled. Patients were excluded from the study if they did not have a histological diagnosis for AK, if they were older than 85 years, or if they did not comply with the protocol. All patients had responded to a notice asking for volunteers.
Main Outcome Measures: The number and appearance of lesions were evaluated before, during, and after treatment. All adverse effects were recorded.
Results: Lesions treated with 5% imiquimod cream were clinically cleared in 21 (84%) of 25 patients and partially cleared in 2 (8%). Clearance was histologically confirmed 2 weeks after the last application of imiquimod in all patients clinically diagnosed as lesion free. Only 10% of patients treated with imiquimod were clinically diagnosed with recurrence 1 year after treatment. No reduction in the size or number of AK lesions was observed in vehicle-treated patients. Adverse effects reported by patients treated with imiquimod included erythema, edema, induration, vesicles, erosion, ulceration, excoriation, and scabbing. However, imiquimod was well tolerated since all patients completed the 12-week treatment. Only a few, mild adverse reactions to the vehicle cream were reported.
Conclusion: Application of 5% imiquimod cream for 12 weeks is an effective and well-tolerated treatment for AK.
Gupta AK
Cutis. 2002;70(2 suppl):30-36
Actinic keratosis (AK) may be an early stage of carcinoma in situ and invasive carcinoma. Excision or destruction of AKs is one of the most frequently performed procedures in dermatology. The most common treatments for AKs in the United States are liquid nitrogen cryotherapy and 5-fluorouracil. This paper focuses on the topical 5% fluorouracil cream (Efudex), 1% fluorouracil cream (Fluoroplex), and 0.5% fluorouracil cream (Carac) formulations. Our objective was to evaluate the cost-effectiveness of topical fluorouracil cream formulations for managing facial AKs from the perspective of the third-party payer, with a one-year time period. Initial estimates were based on the treatment of facial AKs only, using topical fluorouracil regimens approved by the US Food and Drug Administration. Analysis was based on the efficacy rates of each regimen as found in the literature and summarized using meta-analysis. The cost of therapy included drug-acquisition costs and medical management costs for 1 or 2 topical fluorouracil treatments per calendar year. Sensitivity analysis was performed by evaluating the cost per cured facial AK and the number of patients cured of AK (cost-effectiveness of treatment) for patients with 1 to 20 facial AKs. For one treatment cycle, the average efficacy rates of a topical fluorouracil treatment based on lesional response (proportion of facial AKs cured in a given patient) or patient cure (number of patients whose facial AKs were completely cured) were 87.8% and 62.5%, respectively. For more than 6 AKs, 0.5% fluorouracil cream may be more cost-effective than the 1% and 5% formulations. The true costs of therapy are underestimated however, as the costs of managing adverse events are not included. Our study suggests that once-daily use of 0.5% fluorouracil cream is a cost-effective way of managing a patient with multiple facial AKs.
Salasche SJ, Levine N, Morrison L
J Am Acad Dermatol. 2002;47:571-577
Background: Preliminary studies indicate that topically applied immune response modifiers may be an effective and safe method of treating actinic keratoses (AKs).
Objective: Our aim was to study the potential efficacy of topical 5% imiquimod cream in the treatment of facial or scalp AKs and improve the safety profile by using a novel "cycle" dosing regimen.
Methods: This pilot study is an open-label trial that included 25 patients who had between 5 and 20 discrete AKs within a cosmetic unit of the forehead, scalp, or cheek. Treatment consisted of once-daily application of 5% imiquimod cream, 3 times a week for 4 weeks. to the entire cosmetic unit, followed by a rest period of 4 weeks. The cycle was repeated if any AKs remained after a complete 8-week cycle. A maximum of 3 cycles was permitted (24 weeks). Thirty-three sites in 25 patients were evaluated.
Results: Compliance was excellent with a very tolerable safety profile. Complete clearing of all AKs was noted in 82% (27/33) of anatomic sites in 25 study subjects. Almost half the sites (15/33) were clear at the end of the first cycle. A "therapeutic interval" was noted during the rest period wherein clinical inflammation subsided but AKs continued to clear. An added effect was the uncovering and clinical appearance and subsequent eradication of incipient (subclinical) AKs in the treatment area.
Conclusion: There was excellent compliance with the cycle therapy regimen. The observations and hypotheses made in this pilot study will be tested in controlled, randomized trials with larger study populations. The identification of a therapeutic interval may prove to be beneficial in formulating individualized dosing regimens.
Persaud AN, Shamuelova E, Sherer D, et al
J Am Acad Dermatol. 2002;47:553-556
Background: Actinic keratosis (AK) is the earliest clinical manifestation of squamous cell carcinoma. Metastatic SCC causes the majority of the 1300 to 2300 deaths attributed to nonmelanoma skin cancer in the United States each year. Recent studies have shown that intralesional administration of interferon can be used successfully in the treatment of AK.
Objective: Imiquimod is an immune response modifier, currently approved for the treatment of genital warts. The topically applied immune response modifier acts by up-regulating interferon and other cytokines involved in the cell-mediated immune response at the site of application. The aim of this was to determine the efficacy and safety of imiquimod 5% cream for the treatment of AK.
Methods: Twenty-two patients with AK lesions were treated with imiquimod 5% cream, initially at 3 times per week for 8 weeks, or until total clearance of lesions. Patients applied imiquimod to lesions on one side of the body and vehicle cream to the other side. A total of 17 patients who completed treatment were evaluated for number of lesions and adverse reactions before treatment and at weeks 2, 4, 6, and 8 after initiation of treatment. AK lesions were also assessed 4 and 8 weeks after treatment.
Results: A significant reduction in the average number of lesions per patient was observed for patients treated with imiquimod. The most frequent reactions to treatment were erythema, itching, and scabbing; however, all adverse events were mild to moderate.
Conclusion: Imiquimod 5% cream may be a promising treatment for AK.
Persaud A, Lebwohl M
Am Acad Dermatol. 2002;47(4 suppl):S236-S239
We studied the usefulness of imiquimod cream in the treatment of 3 patients with actinic keratoses. One patient was treated 3 times per week for 4 weeks and had a marked inflammatory response with nearly complete resolution of actinic keratoses. Two subsequent patients were treated in a bilateral paired comparison study. Both patients had similar numbers of actinic keratoses on symmetric areas and treated only one side with imiquimod cream 2 to 3 times per week with frequent rest periods to avoid inflammation. Both experienced marked reductions in actinic keratoses. After 8 weeks, both patients applied imiquimod cream twice per week for 9 months with continued reduction in actinic keratoses on both sides. Treatments were well tolerated. Imiquimod cream appears to be effective in the treatment of actinic keratoses. The main adverse effect is local inflammation, which can be avoided by reducing the frequency of application.
What's new concerning our understanding of actinic keratosis? Find out in this easy-to-navigate collection of recent MEDLINE abstracts compiled by the editors at Medscape Dermatology.
Chamberlain AJ, Kurwa HA
Am J Clin Dermatol. 2003;4:149-155
Photodynamic therapy (PDT) is proposed as an effective therapy with a good safety profile for patients with actinic keratoses. PDT involves the application of a photosensitizer to dysplastic or neoplastic tissue such that when exposed to light of an appropriate wavelength, the target tissue undergoes a cytotoxic reaction. Studies to date have demonstrated that PDT for the treatment of patients with actinic keratoses achieves clearance of lesions with minimal morbidity, maintenance of functional integrity of underlying tissues, and excellent cosmetic results. We present a review of the treatment of patients with actinic keratoses and the role of PDT in this context.
Walker JK, Koenig C
J Fam Pract. 2003;52:184-185
Imiquimod 5% cream, applied 3 times per week for 12 weeks, is effective for treatment of actinic keratosis. Severe erythema and other local reactions occurred in almost everyone receiving treatment, due to imiquimod's immune system-modulating effects. The 25 patients in the treatment group tolerated these adverse effects well. Despite these effects, imiquimod can be used as an alternative to traditional cryotherapy for the treatment of actinic keratosis among selected, motivated patients.
Pariser DM, Lowe NJ, Stewart DM, et al
J Am Acad Dermatol. 2003;48:227-232
Background: Photodynamic therapy (PDT) is a promising new treatment modality for actinic keratoses. Methyl aminolevulinate (MAL) (Metvix, PhotoCure, Oslo, Norway) leads to selective accumulation of photoactive porphyrins in premalignant skin lesions and makes the lesions susceptible to phototoxic effects on illumination with red light.
Objective: This multicenter, randomized, double-blind study compared complete response rates, cosmetic outcome, and patient satisfaction for PDT with cream containing 160 mg/g MAL or placebo cream in the treatment of actinic keratoses.
Methods: After application of the cream under occlusion for 3 hours, the lesions were illuminated by noncoherent red light (570-670 nm, light dose 75 J/cm(2)). Treatment was repeated after 1 week and response was assessed 3 months later. A total of 80 patients were randomized into the study, 42 in the active and 38 in the placebo group.
Results: Complete lesion response rate was higher after MAL PDT than placebo, 89% versus 38% per protocol analysis (P =.001). An excellent or good cosmetic outcome was reported in more than 90% of patients treated with MAL.
Conclusion: In this small study, PDT using topical MAL was a safe and effective treatment for actinic keratoses with excellent cosmetic outcome. It is a promising treatment that could benefit from further study.
Nakaseko H, Kobayashi M, Akita Y, Tamada Y, Matsumoto Y
Br J Dermatol. 2003;148:122-127
Background: Photodynamic therapy (PDT), which employs a combination of a tumour-localizing photosensitizer and visible light, has been used to treat superficial malignancies in the epidermis.
Objectives: To examine histological changes and the role of apoptosis in lesions of actinic keratosis (AK) after PDT using 5-aminolaevulinic acid (ALA) and excimer dye laser.
Methods: After topical ALA-PDT, biopsy specimens were collected from 18 skin lesions in 15 patients with AK. Paraffin-embedded sections of the skin specimens were stained with haematoxylin and eosin. The detection of apoptosis was performed using a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labelling (TUNEL) method, antiactivated caspase-3 antibody and anti-Fas antibody.
Results: One hour after PDT, cells with eosinophilic cytoplasm and markedly stained nuclei were found, and vacuolation of some tumour cells was noted in the lower layer of the epidermis. An infiltrate of lymphocytes and neutrophils was observed in the upper layer of the dermis. One day after PDT, all layers of the epidermis exhibited slightly degenerative necrosis, with shadow cell formation and chromatin condensation around the nuclear membrane in the lower layer of the epidermis. Necrosis in all layers of the epidermis and lymphocyte infiltration in the dermis were found 3 days after PDT. Tumour cells had disappeared and regenerative thickening of the epidermis was observed 7 days after PDT. TUNEL staining revealed apoptosis-positive cells in the epidermis in 8 of 11 specimens obtained 1 day after PDT. Activated caspase-3 expression was noted in the lower layer of the epidermis in four of these eight TUNEL-positive specimens.
Conclusions: Results suggested that apoptosis is involved in tumour cell death after PDT in patients with AK, and that it occurs within 1 day after PDT.
Jorizzo J, Stewart D, Bucko A, et al
Cutis. 2002;70:335-339
The efficacy and safety of a new 0.5% fluorouracil topical cream were compared with vehicle control for the treatment of actinic keratosis (AK). Active treatment applied once daily for 1, 2, or 4 weeks was more effective than vehicle control in achieving reduction from baseline in lesion counts and lesion clearance. Active treatment also resulted in significantly better global assessments of overall improvement. Treatment was effective regardless of the number of baseline lesions. Although longer treatment duration correlated with greater efficacy, treatment for 1, 2, or 4 weeks was effective. This new microsphere-based fluorouracil formulation was generally well tolerated; adverse events were primarily limited to facial irritation that resolved quickly after treatment. This new treatment provides a safe alternative to the topical fluorouracil formulations currently available for the 1-, 2-, or 4-week treatment of AK.
Stockfleth E, Meyer T, Benninghoff B, et al
Arch Dermatol. 2002;138:1498-1502
Background: Actinic keratoses (AKs) are precancerous epidermal lesions found most frequently on areas of the skin exposed to the sun. Several case studies published recently have indicated that 5% imiquimod cream, currently licensed for the treatment of genital warts, may be an effective treatment for AK.
Objective: To assess the efficacy and safety of imiquimod for the treatment of AK.
Design: Patients in this randomized, double-blind, vehicle-controlled study applied 5% imiquimod cream or vehicle to AK lesions 3 times per week for a maximum of 12 weeks or until lesions had resolved. In the event of an adverse reaction, application of imiquimod was reduced to 1 or 2 times per week. Rest periods were also allowed if necessary.
Setting: A specialized outpatient dermatology clinic within a state-funded hospital in Germany.
Patients: The study population was aged 45 to 85 years. Of 52 patients screened, 36 men and women with AK confirmed by histological diagnosis were enrolled. Patients were excluded from the study if they did not have a histological diagnosis for AK, if they were older than 85 years, or if they did not comply with the protocol. All patients had responded to a notice asking for volunteers.
Main Outcome Measures: The number and appearance of lesions were evaluated before, during, and after treatment. All adverse effects were recorded.
Results: Lesions treated with 5% imiquimod cream were clinically cleared in 21 (84%) of 25 patients and partially cleared in 2 (8%). Clearance was histologically confirmed 2 weeks after the last application of imiquimod in all patients clinically diagnosed as lesion free. Only 10% of patients treated with imiquimod were clinically diagnosed with recurrence 1 year after treatment. No reduction in the size or number of AK lesions was observed in vehicle-treated patients. Adverse effects reported by patients treated with imiquimod included erythema, edema, induration, vesicles, erosion, ulceration, excoriation, and scabbing. However, imiquimod was well tolerated since all patients completed the 12-week treatment. Only a few, mild adverse reactions to the vehicle cream were reported.
Conclusion: Application of 5% imiquimod cream for 12 weeks is an effective and well-tolerated treatment for AK.
Gupta AK
Cutis. 2002;70(2 suppl):30-36
Actinic keratosis (AK) may be an early stage of carcinoma in situ and invasive carcinoma. Excision or destruction of AKs is one of the most frequently performed procedures in dermatology. The most common treatments for AKs in the United States are liquid nitrogen cryotherapy and 5-fluorouracil. This paper focuses on the topical 5% fluorouracil cream (Efudex), 1% fluorouracil cream (Fluoroplex), and 0.5% fluorouracil cream (Carac) formulations. Our objective was to evaluate the cost-effectiveness of topical fluorouracil cream formulations for managing facial AKs from the perspective of the third-party payer, with a one-year time period. Initial estimates were based on the treatment of facial AKs only, using topical fluorouracil regimens approved by the US Food and Drug Administration. Analysis was based on the efficacy rates of each regimen as found in the literature and summarized using meta-analysis. The cost of therapy included drug-acquisition costs and medical management costs for 1 or 2 topical fluorouracil treatments per calendar year. Sensitivity analysis was performed by evaluating the cost per cured facial AK and the number of patients cured of AK (cost-effectiveness of treatment) for patients with 1 to 20 facial AKs. For one treatment cycle, the average efficacy rates of a topical fluorouracil treatment based on lesional response (proportion of facial AKs cured in a given patient) or patient cure (number of patients whose facial AKs were completely cured) were 87.8% and 62.5%, respectively. For more than 6 AKs, 0.5% fluorouracil cream may be more cost-effective than the 1% and 5% formulations. The true costs of therapy are underestimated however, as the costs of managing adverse events are not included. Our study suggests that once-daily use of 0.5% fluorouracil cream is a cost-effective way of managing a patient with multiple facial AKs.
Salasche SJ, Levine N, Morrison L
J Am Acad Dermatol. 2002;47:571-577
Background: Preliminary studies indicate that topically applied immune response modifiers may be an effective and safe method of treating actinic keratoses (AKs).
Objective: Our aim was to study the potential efficacy of topical 5% imiquimod cream in the treatment of facial or scalp AKs and improve the safety profile by using a novel "cycle" dosing regimen.
Methods: This pilot study is an open-label trial that included 25 patients who had between 5 and 20 discrete AKs within a cosmetic unit of the forehead, scalp, or cheek. Treatment consisted of once-daily application of 5% imiquimod cream, 3 times a week for 4 weeks. to the entire cosmetic unit, followed by a rest period of 4 weeks. The cycle was repeated if any AKs remained after a complete 8-week cycle. A maximum of 3 cycles was permitted (24 weeks). Thirty-three sites in 25 patients were evaluated.
Results: Compliance was excellent with a very tolerable safety profile. Complete clearing of all AKs was noted in 82% (27/33) of anatomic sites in 25 study subjects. Almost half the sites (15/33) were clear at the end of the first cycle. A "therapeutic interval" was noted during the rest period wherein clinical inflammation subsided but AKs continued to clear. An added effect was the uncovering and clinical appearance and subsequent eradication of incipient (subclinical) AKs in the treatment area.
Conclusion: There was excellent compliance with the cycle therapy regimen. The observations and hypotheses made in this pilot study will be tested in controlled, randomized trials with larger study populations. The identification of a therapeutic interval may prove to be beneficial in formulating individualized dosing regimens.
Persaud AN, Shamuelova E, Sherer D, et al
J Am Acad Dermatol. 2002;47:553-556
Background: Actinic keratosis (AK) is the earliest clinical manifestation of squamous cell carcinoma. Metastatic SCC causes the majority of the 1300 to 2300 deaths attributed to nonmelanoma skin cancer in the United States each year. Recent studies have shown that intralesional administration of interferon can be used successfully in the treatment of AK.
Objective: Imiquimod is an immune response modifier, currently approved for the treatment of genital warts. The topically applied immune response modifier acts by up-regulating interferon and other cytokines involved in the cell-mediated immune response at the site of application. The aim of this was to determine the efficacy and safety of imiquimod 5% cream for the treatment of AK.
Methods: Twenty-two patients with AK lesions were treated with imiquimod 5% cream, initially at 3 times per week for 8 weeks, or until total clearance of lesions. Patients applied imiquimod to lesions on one side of the body and vehicle cream to the other side. A total of 17 patients who completed treatment were evaluated for number of lesions and adverse reactions before treatment and at weeks 2, 4, 6, and 8 after initiation of treatment. AK lesions were also assessed 4 and 8 weeks after treatment.
Results: A significant reduction in the average number of lesions per patient was observed for patients treated with imiquimod. The most frequent reactions to treatment were erythema, itching, and scabbing; however, all adverse events were mild to moderate.
Conclusion: Imiquimod 5% cream may be a promising treatment for AK.
Persaud A, Lebwohl M
Am Acad Dermatol. 2002;47(4 suppl):S236-S239
We studied the usefulness of imiquimod cream in the treatment of 3 patients with actinic keratoses. One patient was treated 3 times per week for 4 weeks and had a marked inflammatory response with nearly complete resolution of actinic keratoses. Two subsequent patients were treated in a bilateral paired comparison study. Both patients had similar numbers of actinic keratoses on symmetric areas and treated only one side with imiquimod cream 2 to 3 times per week with frequent rest periods to avoid inflammation. Both experienced marked reductions in actinic keratoses. After 8 weeks, both patients applied imiquimod cream twice per week for 9 months with continued reduction in actinic keratoses on both sides. Treatments were well tolerated. Imiquimod cream appears to be effective in the treatment of actinic keratoses. The main adverse effect is local inflammation, which can be avoided by reducing the frequency of application.
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