Association between Actinic Keratoses and Potentially Photosensitizing Drugs

Known and potential new risk factors for skin cancer in European populations: a multicentre case-control study

“…Possible associations with skin cancer risks were observed with consumption of parsnips (CMM) and with the use of thiazines (BCC), thiazide diuretics (SCC) and cardiac drugs (CMM), as is consistent with the known photosensitizing potential of these food items and drugs. [15][16][17][18][19][20][40][41][42] Of the food and drug associations studied, only a negative association with pomegranate and ciprofloxacin and a positive association with thiazide diuretics remained significant after correction for multiple testing, germane to previously reported association with increased risks of SCC, CMM and BCC. 42,46 When we further analysed the negative association with ciprofloxacin (Table 5), the numbers taking this antibiotic daily for more than 3 months were low (37 controls, 10 BCC, 7 SCC, 12 CMM) and were almost all from Italy, Germany and Poland.…”

“…Many commonly used drugs may increase cutaneous photosensitivity and some have been shown to increase skin cancer risk. 15,16 Furthermore, in case-control studies reported use of photosensitizing drugs has been associated with increased occurrence of BCC, SCC and actinic keratosis 40,41 and photosensitizing diuretics have been found to associate with increased risks of SCC and CMM. 42 Drug-associated photosensitivity may reflect conversion to electrophiles and ⁄or sources of reactive oxygen species, while other drugs interact synergistically with UV radiation.…”

“…There are many potential confounders such as use of ciprofloxacin in patients who are sick and less able to lead an active outdoor life. The 'new' variables were investigated based on the hypothesis that they might be related to skin cancer through the biological mechanisms discussed above or because associations have been previously observed, 15,16,18,34,[40][41][42][43]46 but not generally accepted. These associations may be real and deserve further exploration; however, they might also be chance findings.…”

Phototoxic and Photoallergic Reactions

“…Epidemiological studies and recent reports are showing this may also be significant for humans. In 1999, the group of Przybilla showed an association between actinic keratosis and the use of potentially photosensitizing chemicals [13]. More recent data tend to confirm an increased risk in patients on long-term PUVA treatments [14] and, also in those exposed to fluorquinolones, diuretics [15], and voriconazole [16].…”

“…Apart from psoralens, naproxen, chlorpromazine, and the fluorquinolones, particularly lomefloxacin, also have the capacity to induce DNA aggression upon UV exposure, in vitro, and to increase epidermal neoplasia in animals [8,9]. This concern may have to be taken into account, namely as severe photosensitivity associated with skin cancer has been observed with voriconazole [16] and ciprofloxacin (personal experience) and epidemiological studies seem to correlate exposure to photoactive drugs and an increase in the risk of developing actinic keratoses, nonmelanoma skin cancer and, even, malignant melanoma [13,15]. Also, photoaging may be enhanced by the exposure to topical or systemic photosensitizers.…”