Actinic Keratoses

Actinic keratoses often have adherent scales and are sometimes more easily felt than seen. Actinic keratoses can appear thickened or hypertrophic and sometimes form a cutaneous horn. They may be pink, red, or, less commonly, gray or brown. Lesions frequently develop in sun-exposed areas (eg, balding scalp, face, lateral neck, distal upper or lower extremities). Diffuse involvement of the lip is called actinic cheilitis.

Diagnosis of actinic keratoses is often based on visual and tactile examination; lesions feel rough and scaly on palpation. They should be differentiated from seborrheic keratoses Seborrheic Keratoses Seborrheic keratoses are superficial, often pigmented, epithelial lesions that are usually warty but may occur as smooth papules. The cause of seborrheic keratosis is unknown, but genetic mutations... read more , which increase in number and size with age. Seborrheic keratoses tend to appear waxy and stuck-on but can take on an appearance similar to that of actinic keratoses. Close inspection usually reveals distinguishing characteristics of the lesion. An actinic keratosis can also be distinguished from a seborrheic keratosis by the rough, gritty feel of the scale and the erythema. Unlike actinic keratoses, seborrheic keratoses also occur on non–sun-exposed areas of the body and are not precancerous.

Treatment options depend on the number of lesions, their location, extent of photodamage, and patient preference, but typically they are divided into two categories:

In lesion-directed therapy, individual lesions are physically removed. This option may be better if the patient has only a few actinic keratoses, or if the patient is unable or unwilling to undergo other therapy options. Cryosurgery (freezing with liquid nitrogen) is the most common lesion-directed therapy. Curettage (scraping with a curette) is an alternative. Lesion-directed therapies have the benefit of being single, in-office procedures, but they may not address subclinical changes and have a higher risk of scarring.

In field-directed therapy, topical treatments are applied to larger, diffuse areas of involvement. Topical fluorouracil (5-FU) cream and imiquimod cream are the usual first-line drug treatments. Alternatives include diclofenac gel and tirbanibulin ointment.

These topical drugs can cause inflammation (often with redness and scaling) and pain during treatment and usually for 1 to 2 weeks afterward.

Photodynamic therapy is another type of field-directed therapy. It involves topical application of a photosensitizer (eg, aminolevulinate, methyl aminolevulinate) followed by light of a specific wavelength that preferentially affects photodamaged skin. Like topical field-directed therapy, photodynamic therapy can cause redness and scaling during treatment. More than one treatment session may be needed.

If patients do not respond to therapy, clinicians should consider doing a biopsy to rule out squamous cell carcinoma.

Patients should also be told about the importance of sun-protective measures Prevention The skin may respond to sunlight with chronic (eg, dermatoheliosis [photoaging], actinic keratosis) or acute (eg, photosensitivity, sunburn) changes. The sun emits a wide range of electromagnetic... read more .