Actinic Keratosis is a very common skin disease characterized by superficial lesions, which appear on skin that has been exposed to the sun. (1);(2).
References +

1. Berman et al.Pharmacotherapy of Actinic Keratosis.Expert Opin. Pharmacother,2009

2. Stockfleth et al.textbook.Managingskin cancer

3. Berman et al.”Actinic Keratosis:sequelae and Treatments”Supplement tothe jounal of Family Practice.May2006

4. Lober BA,Lober CW, “ Actinic Keratosis insquamous cell carcinoma,”South Med J. 2000

5. D.de Berber, IM. McGregor and B.R. Hughes, Guidelines for themanegement of actinic keratosis,”On behalf of the British association of Dermatologists Therapy Guidelines and Audit Subcommittee.

Actinic Keratosis are deemed pre-cancerous lesions because they can evolve into squamous cell carcinoma. As such, ALL ACTINIC KERATOSIS MUST BE TREATED.

Actinic Keratosis usually appear as one or more brownish red spots with a scaly surface. The affected skin surface may be rough and present some pain or itching. Changes are usually better identified by touch rather than by sight, as they are not visible lesions. (3);(4)

The most frequent areas for the appearance of Actinic Keratosis are the face, scalp (bald men), back of hands, ears and chest. Actinic Keratosis appear most frequently in the elderly population, and in light-skinned individuals, who have been exposed to a lot of sunlight because of outdoor work or living in very hot countries. (4);(5)

The best way to prevent Actinic Keratosis is to avoid sun exposure and if doing so head, face and ears should be protected and a high SPF sunscreen should be used.