702.0 – Actinic keratosis

Actinic, or solar, keratosis is a neoplastic condition in which precancerous epithelial lesions are found on sun-exposed areas of the body. This is a very common condition in fair-skinned individuals (eg, northern European descent) and virtually unseen in people of darker skin types. They are commonly seen on sun-exposed skin of the face, neck, upper chest, forearms, and dorsal hands. These flat, scaly papules are of varying sizes and usually begin as "rough" localized skin lesions that the patient feels but are difficult to see. Actinic keratoses have the potential to evolve into squamous cell carcinoma. They are usually asymptomatic but may be pruritic or painful. The frequency of actinic keratoses increases with increasing age and cumulative lifetime sun exposure. They are also more common in immunosuppressed individuals. They may resolve with protection from UV light. Patients with actinic keratoses are also at higher risk for developing non-melanoma skin cancer. 

Subtle, barely elevated to thicker, hypertrophic, rough papules with ill-defined borders. There may be adherent scale with color variation from whites to yellows and, more rarely, a reddish-brown or gray-colored scale. The papules usually have an underlying red base. Size varies. When large in number, actinic keratoses may coalesce to form plaques. Lower lip involvement with actinic keratoses is considered actinic cheilitis.

Actinic keratoses are often more easily palpated (with light touch) than seen.

Actinic keratoses are usually smaller and more irregular than
flat warts,  common warts, and superficial basal cell carcinomas.
Bowen's disease
Psoriasis
Seborrheic dermatitis
Squamous cell carcinoma
Seborrheic keratosis
Disseminated superficial actinic porokeratosis
Discoid lupus erythematosus

This is a clinical diagnosis. If necessary, confirm with a skin biopsy. Biopsies should be performed on recurrent, hyperkeratotic, large (greater than 6 mm), or indurated lesions to rule out invasive carcinoma. 

Aggressive sun avoidance / sun-protective measures should be instituted. Patients should wear protective clothing, broad-brimmed hats, and a broad spectrum (UVA and UVB blocking) sunscreen with SPF 30 or higher when exposed to the sun.

If patient does not respond to therapy, perform a biopsy to rule out squamous cell carcinoma.

Treat individual lesions with liquid nitrogen cryotherapy or superficial curettage and cautery.

5-Fluorouracil 5% cream (Efudex®, Fluoroplex®) can be applied twice daily to areas of more extensive involvement for about 2 weeks. It will cause a vigorous reaction (redness, hemorrhagic crusting). Have the patient apply an emollient such as petroleum jelly to aid in crust dissolution.
 
Other treatments that may be tried include:

• Topical imiquimod 5% cream applied to affected areas 2–3 times per week for 12 weeks
• Photodynamic therapy with methyl aminolevulinate
• 0.3% Topical adapalene gel applied to affected areas 1–2 times daily
• Topical 3.0% diclofenac in 2.5% hyaluronan gel applied to affected areas twice daily

A low-fat diet (less than 21% of calories from fat) has been shown to reduce the incidence of actinic keratoses. Actinic keratoses will decrease and sometimes resolve with sunscreen use.

Duncan KO, Geisse JK, Leffell DJ. Epithelial precancerous lesions. In: Fitzpatrick TB, Wolff K, eds. Fitzpatrick's Dermatology in General Medicine. 7th ed. New York, NY: McGraw-Hill; 2008:1007-1015.

Ben M'barek L, Mebazaa A, Euvrard S, Frances C, Thervet E, Morel P, Menasché S, Legendre C, Lebbe C. 5% topical imiquimod tolerance in transplant recipients. Dermatology. 2007;215(2):130-3. PubMed Id: 17684375

Braathen LR, Szeimies RM, Basset-Seguin N, Bissonnette R, Foley P, Pariser D, Roelandts R, Wennberg AM, Morton CA, International Society for Photodynamic Therapy in Dermatology. Guidelines on the use of photodynamic therapy for nonmelanoma skin cancer: an international consensus. International Society for Photodynamic Therapy in Dermatology, 2005. J Am Acad Dermatol. 2007 Jan;56(1):125-43. PubMed Id: 17190630

Falagas ME, Angelousi AG, Peppas G. Imiquimod for the treatment of actinic keratosis: A meta-analysis of randomized controlled trials. J Am Acad Dermatol. 2006 Sep;55(3):537-8. PubMed Id: 16908371

James WD, Berger TG, Elston DM. Epidermal Nevi, neoplasms, and cysts. In: James WD, Berger TG, Elston DM, Odom RB, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 10th ed. Philadelphia, PA: Saunders Elsevier; 2006:641-643.

Lee PK, Harwell WB, Loven KH, Phillips TJ, Whiting DA, Andres KL, Lee JH. Long-term clinical outcomes following treatment of actinic keratosis with imiquimod 5% cream. Dermatol Surg. 2005 Jun;31(6):659-64. PubMed Id: 15996416

Szeimies RM, Gerritsen MJ, Gupta G, Ortonne JP, Serresi S, Bichel J, Lee JH, Fox TL, Alomar A. Imiquimod 5% cream for the treatment of actinic keratosis: results from a phase III, randomized, double-blind, vehicle-controlled, clinical trial with histology. J Am Acad Dermatol. 2004 Oct;51(4):547-55. PubMed Id: 15389189

Cockerell CJ. Histopathology of incipient intraepidermal squamous cell carcinoma ("actinic keratosis"). J Am Acad Dermatol. 2000 Jan;42(1 Pt 2):11-7. PubMed Id: 10607351

Black HS, Herd JA, Goldberg LH, Wolf JE, Thornby JI, Rosen T, Bruce S, Tschen JA, Foreyt JP, Scott LW, et al. Effect of a low-fat diet on the incidence of actinic keratosis. N Engl J Med. 1994 May 5;330(18):1272-5. PubMed Id: 8145782

Thompson SC, Jolley D, Marks R. Reduction of solar keratoses by regular sunscreen use. N Engl J Med. 1993 Oct 14;329(16):1147-51. PubMed Id: 8377777

Appearance
No Acute Distress

Body Location
Anterior Lower Leg
Anti-Helical Rim of Ear
Arm
Cheek
Dorsum of Hand
Ear
Eyebrow
Face
Fingers
Forearm
Forehead
Frontal Scalp
Hand or Fingers
Helical Rim of Ear
Lips
Lower Leg
Nose
Occipital Scalp
Posterior Aspect of Ear
Superior Chest
Superior Eyelid
Superior Lip
Temple
Upper Arm
Upper Back
Vertex Scalp

Distribution
Photodistributed (Sun-Exposed)
Unilateral

Exposures
Sun Exposure - History of Severe Sunburns

Lesion
Auspitz Sign
Scaly Papule

Occupations
Military

Signs and Symptoms
No Fever (Afebrile, Apyrexial)

Temporal
Developed Chronically Lasting Months to Years
Developed Steadily Over Weeks to Months

Medical History
Bone Marrow Transplant
Immunosuppression/Immunocompromised
S-P Organ Transplant NOS
S-P Renal Transplant