Actinic Keratosis - Prevention

Prevention

Preventive measures recommended for actinic keratosis are similar to those for skin cancer:

• Not staying in the sun for long periods of time without protection (e.g., sunscreen, clothing, hats)
• Frequently applying powerful sunscreens with SPF ratings greater than 30 and that also block both UVA and UVB light
• Wearing sun protective clothing such as hats, long-sleeved shirts, long skirts, or trousers
• Avoiding sun exposure during noon hours is very helpful because ultraviolet light is the most powerful at that time

According to an article in the Journal of Investigative Dermatology (2005) 125, 93–97; doi:10.1111/j.0022-202X.2005.23733.x, entitled, "Human Papillomavirus-DNA Loads in Actinic Keratoses Exceed those in Non-Melanoma Skin Cancers", actinic keratosis may contain a significant amount of infectious human papillomavirus. Verbatim: "HPV presents in significantly higher viral loads in actinic keratosis (AK), which are the precursor lesions of squamous cell carcinoma (SCC), than in SCC. Viral loads of 1 HPV-DNA copy per less than 50 cells were measured in 40% of AK. The higher viral loads in AK are likely to reflect enhanced HPV-DNA replication. This may be because of intense keratinocyte proliferation and differentiation in AK favoring amplification of commensalic HPV. Active HPV replication and presumably enhanced gene expression may in turn stimulate keratinocyte proliferation and contribute to carcinogenesis in these early stages of NMSC development. HPV-E6 proteins were recently shown to inhibit UV-induced apoptosis by abrogation of Bak in response to UV damage (Jackson and Storey, 2000) and to bind a protein required for repair of single strand DNA breaks (Iftner et al, 2002). Thereby, accumulation of UV-induced mutations and oncogenic transformation might be facilitated in cases of active HPV infection."