Actinic keratoses (AKs) are abnormal, precancerous keratinocyte proliferation that forms as a result of persistent ultraviolet (UV) radiation exposure. AK treatment can be lesion- or field-directed. According to the field cancerization theory, the skin around AK is at an elevated risk of malignant transformation since it has been subjected to the same chronic UV radiation. Field-directed treatments had the ability to address subclinical damage, lower AK recurrence rates, and perhaps minimize the chance of developing squamous cell carcinoma (SCC). According to published clinical research, photodynamic treatment (PDT) using either aminolevulinic acid (ALA) or methyl aminolevulinate resulted in lesion clearance rates ranging from 81 to 91% (MAL). For a review, researchers presented fair and complete narrative literature, focusing on light-based and topical treatments with an emphasis on field-therapy characteristics, and offered a therapeutic algorithm for selecting a suitable treatment in the clinical environment.

Clinical research on several topical therapies has also been reported. Across numerous trials, complete clinical clearance (CCC) was considerably greater in patients treated with a combination of 5-fluorouracil and salicylic acid (5-FU–SA) than in the vehicle group, and CCC varied between 46% and 48% following imiquimod therapy. Furthermore, therapy with diclofenac sodium (DFS) resulted in a reduction in lesion diameters ranging from 67% to 75%. Similar findings have been reported with piroxicam, a nonsteroidal anti-inflammatory medication (NSAID) with higher cyclooxygenase (COX)-1 activity than DFS. 

In addition, active treatments with ingenol mebutate were much more successful than vehicles in eliminating AK lesions. All of the treatments produced modest, localized cutaneous responses. PDT with traditional light sources was related to greater pain and/or discomfort, but PDT using daylight as the light source was associated with decreased pain and, in some cases, no pain at all. 

Though there was no commonly acknowledged strategy for the treatment of AKs, field-directed therapy could be especially beneficial for treating photo-exposed regions with many AKs. More direct comparisons between these field-directed medicines might aid doctors in determining the optimum therapeutic method.