Sunbeds

Abstract

Ultraviolet radiation (UVR)-emitting sunbeds for self-tanning purposes have been available for around two decades. Originally claimed to be safe by commercial interests, because new technology enabled the emission of mostly UVA (315-400 nm) radiation, rather than the more profuse UVB (280-315 nm) present with UVA in midday summer or tropical sunlight, these devices have now been demonstrated to have similar deleterious cutaneous effects. However, such effects have taken time to define, and sunbed operators have continued to advocate their equipment as safe, with a tendency to tan without the sunburn characteristic of sunlight exposure; now that it indeed appears that sunbed UVA, along with not inconsiderable amounts of UVB usually also emitted, is similarly damaging to sunlight, a recent move has been to produce lamps emitting truly sunlight-like radiation instead. UVB and UVA both apparently exert their effects mainly through cutaneous cellular DNA damage, probably particularly in the germinative basal cell layer, UVB very likely through direct absorption and UVA more through secondary photosensitisation effects. As a result, sunburn, a tissue repair process, is initiated, along with an immediate tanning effect in those who tan readily; the former reaction, which may vary from subclinical to severe, sometimes leads in excessive instances to a persisting cutaneous hypersensitivity, or very rarely in extreme cases a fatal outcome. Delayed tanning also occurs after UVR exposure, again as a result of cutaneous DNA damage, the latter more marked in the fair-skinned who are perhaps more likely to use sunbeds in the first place. In addition, a sunbed tan usually only mildly protects the skin against later sunlight-induced damage, while irregular patchy tanning, dryness and itching of the skin are also common outcomes, and induction of the unsightly, pruritic polymorphic light eruption and more severe potentially debilitating disorders such as lupus erythematosus are possible; severe cutaneous burning may also occur in sunbed users taking certain photosensitising medications. In the longer term, again particularly in the fair-skinned, skin fragility with blistering, crusting and often superficial scarring occasionally occur over months of sunbed use, while skin photoageing seems likely in all long-term regular users; this has not yet been unequivocally demonstrated in human subjects, however, although marked degenerative changes are readily induced in animals. Finally, there have now been reports of skin pre-cancers in man, particularly too in the fair-skinned who have used sunbeds regularly over several years; cancers are readily produced in animals. Adequate warnings on sunbeds are therefore strongly advocated and exposure to such devices strongly discouraged.