Pharmacological Agents Used in the Prevention and Treatment of Actinic Keratosis: A Review

Abstract

Actinic keratosis (AK) is among the most commonly diagnosed skin diseases with potentially life-threatening repercussions if left untreated. Usage of pharmacologic agents represents one of many therapeutic strategies that can be used to help manage these lesions. Ongoing research into these compounds continues to change our clinical understanding as to which agents most benefit particular patient populations. Indeed, factors such as past personal medical history, lesion location and tolerability of therapy only represent a few considerations that clinicians must account for when prescribing appropriate treatment. This review focuses on specific drugs used in either the prevention or treatment of AKs. Nicotinamide, acitretin and topical 5-fluorouracil (5-FU) continue to be used with fidelity in the chemoprevention of actinic keratosis, although some uncertainty persists in regard to which agents should be used in immunocompetent vs. immunodeficient/immunosuppressed patients. Topical 5-FU, including combination formulations with either calcipotriol or salicylic acid, as well as imiquimod, diclofenac and photodynamic light therapy are all accepted treatment strategies employed to target and eliminate AKs. Five percent of 5-FU is regarded as the most effective therapy in the condition, although the literature has conflictingly shown that lower concentrations of the drug might also be as effective. Topical diclofenac (3%) appears to be less efficacious than 5% 5-FU, 3.75–5% imiquimod and photodynamic light therapy despite its favorable side effect profile. Finally, traditional photodynamic light therapy, while painful, appears to be of higher efficacy in comparison to its more tolerable counterpart, daylight phototherapy.

Topical Immunotherapy for Actinic Keratosis and Field Cancerization

“…Currently available concentrations are 2.5%, 3.75%, and 5%, which are applied three times a week for 12–16 weeks [ 11 ]. However, short-term application (4 weeks) has shown similar efficacy to that of long-term application [ 11 ].…”

“…These include local pain, inflammation, itching, and erythema that are positively correlated with immune activation to systemic flu-like symptoms such as myalgia, fever, and fatigue, mostly due to its role as an interferon inducer [ 13 ]. Nevertheless, this treatment is usually well tolerated and only a few patients have to leave it due to adverse effects [ 11 ].…”

“…Diclofenac is a well-known non-steroidal anti-inflammatory drug (NSAID) categorized under the phenylacetic acid class, extensively utilized for its anti-inflammatory and analgesic properties. Diclofenac inhibits cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), resulting in the inhibition of the arachidonic acid cascade and preventing the formation of thromboxane and prostaglandins (PGs) [ 11 , 16 ]. COX-2 expression and PG production are induced following skin exposure to UV radiation [ 17 ].…”

Efficacy and safety of tirbanibulin 1% ointment in actinic keratoses: Data from two phase‐III trials and the real‐life clinical practice presented at the European Academy of Dermatology and Venereology Congress 2022

“…SCC is one the most frequent malignant neoplasms in white populations with annual incidence rates on the rise in several European countries over the last few decades 2 . The early detection and proper management of AK is therefore imperative to reduce the risk of SCC 3,4 …”

“…2 The early detection and proper management of AK is therefore imperative to reduce the risk of SCC. 3,4 Actinic keratoses are dry scaly patches of skin that may appear as pink, red scaling, rough (1-5 mm) papules or plaques or be thin or thickened (hyperkeratotic) in appearance. 5 AKs are often asymptomatic but can be sore or itchy 6 and present as single or multiple discrete or confluent lesions that are either clinically observable with the naked eye or subclinically visible under a microscope.…”