Sun care and photosensitivity
During summer direct sun exposure increases; boosting vitamin D levels, improving bone health and even mood. Melanin production is also stimulated by the sun; this hormone makes the skin darker in people who acquire a tan. Overexposure to ultraviolet rays could have very damaging long-lasting consequences, like: premature ageing of the skin or skin cancer; as well as sunburn or photosensitivity reactions.
In order to maximise sun benefits, whilst minimising the associated risks, it is key that a good sun cream is used to prevent sunburns, which are painful, could last up to one week and predispose to skin cancer in the future. Complete sun avoidance (wearing proper clothes, sun glasses and a hat) may be required under certain circumstances. The darker the skin, the better it usually copes with the sun radiation. This is the reason why being pale and having freckles or moles, may increase the risk of developing skin cancer in this situation.
Sun cream provides a barrier between your skin and the sun that can protect you from the harmful radiation. However, the protection only lasts for a finite amount of time and should be re-applied periodically (usually after two hours). It is important that a thick enough layer of sun cream is applied and that it is allowed to absorb into the skin before being exposed to the sun. The NHS recommends to use a minimum sun protector factor (SPF) of 30. The SPF measures how well the product protects skin against sunburn; for example, SPF 20 means that it would take 20 times longer to burn the skin with a sunscreen on than it does without it. However, it is wrong to think that more time under the sun applying SPF 50+ products is possible, as other factors play an important role in the aetiology of skin sunburns.
Some diseases have been related to abnormal photosensitivity reactions, related to painful severe rash after ultraviolet exposure. Moreover, patients taking certain drugs are also at a higher risk of suffering these serious skin reactions. The table below summarizes common drugs and medical conditions associated with photosensitivity. Patients in these categories should avoid direct sun exposure or use a SPF 50+ cream if sun avoidance is not an option.