There are a variety of treatment options for<unk>  depending on the patient and the clinical characteristics of the lesion.<unk> s show a wide range of features, which guide decision-making in choosing treatment. As there are multiple effective treatments, patient preference and lifestyle are also factors that physicians consider when determining the management plan for<unk> . Regular follow-up is advisable after any treatment to make sure no new lesions have developed and that old ones are not progressing. Adding topical treatment after a procedure may improve outcomes. Medication Topical medications are often recommended for areas where multiple or ill-defined<unk> s are present, as the medication can easily be used to treat a relatively large area. Fluorouracil cream Topical fluorouracil (5-FU) destroys<unk> s by blocking methylation of thymidylate synthetase, thereby interrupting DNA and RNA synthesis. This in turn prevents the proliferation of dysplastic cells in<unk> . Topical 5-FU is the most utilized treatment for<unk> , and often results in effective removal of the lesion. Overall, there is a 50% efficacy rate resulting in 100% clearance of<unk> s treated with topical 5-FU. 5-FU may be up to 90% effective in treating non-hyperkeratotic lesions. While topical 5-FU is a widely used and cost-effective treatment for<unk> s and is generally well tolerated, its potential side-effects can include: pain, crusting, redness, and local swelling. These adverse effects can be mitigated or minimized by reducing the frequency of application or taking breaks between uses. The most commonly used application regimen consists of applying a layer of topical cream to the lesion twice a day after washing; duration of treatment is typically 2–4 weeks to thinner skin like the cheeks and up to 8 weeks for the arms; treatment of up to 8 weeks has demonstrated a higher cure rate. Imiquimod cream Imiquimod is a topical immune-enhancing agent licensed for the treatment of genital warts. Imiquimod stimulates the immune system through the release and up-regulation of cytokines. Treatment with Imiquimod cream applied 2–3 times per week for 12 to 16 weeks was found to result in complete resolution of<unk> s in 50% of people, compared to 5% of controls. The Imiquimod 3.75% cream has been validated in a treatment regimen consisting of daily application to entire face and scalp for two 2-week treatment cycles, with a complete clearance rate of 36%. While the clearance rate observed with the Imiquimod 3.75% cream was lower than that observed with the 5% cream (36 and 50 percent, respectively), there are lower reported rates of adverse reactions with the 3.75% cream: 19% of individuals using Imiquimod 3.75% cream reported adverse reactions including local erythema, scabbing, and flaking at the application site, while nearly a third of individuals using the 5% cream reported the same types of reactions with Imiquimod treatment. However, it is ultimately difficult to compare the efficacy of the different strength creams directly, as current study data varies in methodology (e.g. duration and frequency of treatment, and amount of skin surface area covered). Ingenol mebutate gel Ingenol mebutate is a newer treatment for<unk>  used in Europe and the United States. It works in two ways, first by disrupting cell membranes and mitochondria resulting cell death, and then by inducing antibody-dependent cellular cytotoxicity to eliminate remaining tumor cells. A 3-day treatment course with the 0.015% gel is recommended for the scalp and face, while a 2-day treatment course with the 0.05% gel is recommended for the trunk and extremities. Treatment with the 0.015% gel was found to completely clear 57% of<unk> , while the 0.05% gel had a 34% clearance rate. Advantages of ingenol mebutate treatment include the short duration of therapy and a low recurrence rate. Local skin reactions including pain, itching and redness can be expected during treatment with ingenol mebutate. This treatment was derived from the petty spurge, Euphorbia peplus which has been used as a traditional remedy for keratosis. Diclofenac sodium gel Topical diclofenac sodium gel is a nonsteroidal anti-inflammatory drug that is thought to work in the treatment of<unk>  through its inhibition of the arachidonic acid pathway, thereby limiting the production of prostaglandins which are thought to be involved in the development of UVB-induced skin cancers. Recommended duration of therapy is 60 to 90 days with twice daily application. Treatment of facial<unk>  with diclofenac gel led to complete lesion resolution in 40% of cases. Common side effects include dryness, itching, redness, and rash at the site of application. Retinoids Topical retinoids have been studied in the treatment of<unk>  with modest results, and the American Academy of Dermatology does not currently recommend this as first-line therapy. Treatment with adapalene gel daily for 4 weeks, and then twice daily thereafter for a total of nine months led to a significant but modest reduction in the number<unk> s compared to placebo; it demonstrated the additional advantage of improving the appearance of photodamaged skin. Topical tretinoin is ineffective as treatment for reducing the number of<unk> s. For secondary prevention of<unk> , systemic, low-dose acitretin was found to be safe, well tolerated and moderately effective in chemoprophylaxis for skin cancers in kidney transplant patients. Acitretin is a viable treatment option for organ transplant patients according to expert opinion. Tirbanibulin Tirbanibulin (Klisyri) was approved for medical use in the United States in December 2020, for the treatment of<unk>  on the face or scalp. Procedures Cryotherapy Cryosurgery instrument used to treat<unk>  Liquid nitrogen (−195.8 °C) is the most commonly used destructive therapy for the treatment of<unk>  in the United States. It is a well-tolerated office procedure that does not require anesthesia. Cryotherapy is particularly indicated for cases where there are fewer than 15 thin, well-demarcated lesions. Caution is encouraged for thicker, more hyperkeratotic lesions, as dysplastic cells may evade treatment. Treatment with both cryotherapy and field treatment can be considered for these more advanced lesions. Cryotherapy is generally performed using an open-spray technique, wherein the<unk>  is sprayed for several seconds. The process can be repeated multiple times in one office visit, as tolerated. Cure rates from 67 to 99 percent have been reported, depending on freeze time and lesion characteristics. Disadvantages include discomfort during and after the procedure; blistering, scarring and redness; hypo- or hyperpigmentation; and destruction of healthy tissue. Photodynamic therapy Interim result of phototherapy for<unk>  with methyl aminolevulinate one week after exposure. Patient has light skin, blue eyes.<unk> s are one of the most common dermatologic lesions for which photodynamic therapy, including topical methyl aminolevulinate (MAL) or 5-aminolevulinic acid (5-ALA), is indicated. Treatment begins with preparation of the lesion, which includes scraping away scales and crusts using a dermal curette. A thick layer of topical MAL or 5-ALA cream is applied to the lesion and a small area surrounding the lesion, which is then covered with an occlusive dressing and left for a period of time. During this time the photosensitizer accumulates in the target cells within the<unk>  lesion. The dressings are then removed and the lesion is treated with light at a specified wavelength. Multiple treatment regimens using different photosensitizers, incubation times, light sources, and pretreatment regimens have been studied and suggest that longer incubation times lead to higher rates of lesion clearance. Photodynamic therapy is gaining in popularity. It has been found to have a 14% higher likelihood of achieving complete lesion clearance at 3 months compared to cryotherapy, and seems to result in superior cosmetic outcomes when compared to cryotherapy or 5-FU treatment. Photodynamic therapy can be particularly effective in treating areas with multiple<unk>  lesions. Surgical techniques *Surgical excision: Excision should be reserved for cases when the<unk>  is a thick, horny papule, or when deeper invasion is suspected and histopathologic diagnosis is necessary. It is a rarely utilized technique for<unk>  treatment. *Shave excision and curettage (sometimes followed by electrodesiccation when deemed appropriate by the physician): This technique is often used for treatment of<unk> s, and particularly for lesions appearing more similar to squamous cell carcinoma, or those that are unresponsive to other treatments. The surface of the lesion can be scraped away using a scalpel, or the base can be removed with a curette. Tissue can be evaluated histopathologically under the microscope, but specimens acquired using this technique are not often adequate to determine whether a lesion is invasive or intraepidermal. *Dermabrasion: Dermabrasion is useful in the treatment of large areas with multiple<unk>  lesions. The process involves using a hand-held instrument to "sand" the skin, removing the stratum corneum layer of the epidermis. Diamond fraises or wire brushes revolving at high speeds are used. The procedure can be quite painful and requires procedural sedation and anesthetic, necessitating a hospital stay. One-year clearance rates with dermabrasion treatment are as high as 96%, but diminish drastically to 54% at five years. Laser therapy Laser therapy using carbon dioxide () or erbium:yttrium aluminum garnet (Er:YAG) lasers is a treatment approach being utilized with increased frequency, and sometimes in conjunction with computer scanning technology. Laser therapy has not been extensively studied, but current
Actinic keratosis
Squamous cell skin cancer
Hydrocarbon keratosis
Arsenical keratosis
Reactional keratosis
Seborrheic keratosis
Smokeless tobacco keratosis
PUVA keratosis