Sun and Ultraviolet Exposure in Athletes

The sun delivers ultraviolet A (UVA) and ultraviolet B (UVB). Ultraviolet B causes most sunburn, both types contribute to skin cancer, and ultraviolet A penetrates more deeply and drives photoageing and most drug photosensitivity reactions. Exposure is stronger at higher altitude, where the thinner atmosphere filters less, nearer the equator, in summer, and in the middle of the day, and it is added to by reflection off snow, water and sand, with snow reflecting the most. Ultraviolet exposure can stay high under cloud cover, so burning is possible on an overcast day, and a cool wind is falsely reassuring because it does nothing to reduce ultraviolet. The ultraviolet index gives a simple guide, and protection is worth taking once it reaches 3 or above. Beyond the skin, the eyes are also at risk, and intense reflected sun on snow or water can cause a painful surface eye injury, called photokeratitis or snow blindness. All skin tones can sustain ultraviolet damage and develop skin cancer, though the risk is higher in fair-skinned people who burn easily, who need to take particular care.

Sunburn is red, hot and painful skin that appears within a few hours of exposure and peaks over the following day, sometimes with swelling and, when more severe, blistering. Management is simple: get out of the sun, cool the skin with cool water and a soothing aftersun or aloe vera, keep well hydrated, take simple pain relief such as paracetamol or an anti-inflammatory if suitable, and avoid further sun until the skin has healed. Most sunburn settles over a few days. The clinician stays alert to more serious situations, including extensive blistering or marked swelling, sunburn accompanied by the features of heat illness, and any changing skin lesion that needs a proper look, which is where the red flags matter.

Good protection combines several measures. A broad-spectrum sunscreen of at least sun protection factor (SPF) 30, with at least a 4-star ultraviolet A rating or the ultraviolet A circle logo, is applied generously, since most people apply too little, and reapplied every two hours and straight after swimming, towel drying or heavy sweating, even when it is labelled water-resistant. Sunscreen alone is not enough, so it is paired with tightly woven clothing or garments with an ultraviolet protection factor (UPF) rating, a wide-brimmed hat, wrap-around sunglasses that block ultraviolet, and time in the shade, avoiding the strongest sun, which in the UK is between 11am and 3pm. The lips are easily missed and are protected with a lip balm that contains an SPF. For athletes, the practical trick is to build reapplication into the session, at breaks and after being in water, and to use sweat-resistant and water-resistant formulations rather than relying on a single morning application.

Some medicines make the skin react abnormally to ultraviolet, either as an exaggerated sunburn, called a phototoxic reaction, or as an itchy rash, called a photoallergic reaction. Examples that matter for athletes include doxycycline and other tetracycline antibiotics, some other antibiotics such as the fluoroquinolones, thiazide diuretics used for blood pressure, some non-steroidal anti-inflammatory drugs (NSAIDs), amiodarone, the retinoids used for skin conditions, St John's Wort and some antifungal medicines. The classic situation in sport is an athlete taking doxycycline for malaria prevention who then trains in strong sun and burns more easily than expected. The management is to be aware of the risk and step up sun protection, and where a reaction is troublesome, to review the timing or a possible alternative with the prescriber. An essential medicine such as malaria prophylaxis is not stopped without advice, and an alternative antimalarial may be considered after an individual assessment of the travel risk. Any medicine is also checked against anti-doping rules in the usual way.

• •National Health Service (NHS) advice on sun safety and sunburn covers sunscreen use, protective clothing and when to seek help.
• •TravelHealthPro provides sun protection guidance aimed at travellers, including reflected ultraviolet and eye protection.
• •The British Association of Dermatologists and Cancer Research UK inform skin cancer prevention and the use of the ultraviolet index.
• •Product information for medicines such as doxycycline sets out their photosensitivity risk and precautions.

• •Ultraviolet exposure is stronger at altitude, nearer the equator, in summer and at midday, and is added to by reflection off snow, water and sand.
• •Ultraviolet can stay high under cloud cover, and a cool wind is falsely reassuring, so burning is possible on cool, overcast days.
• •Manage sunburn by cooling, hydrating and simple pain relief, and refer extensive blistering, marked swelling or any changing skin lesion.
• •Protect with broad-spectrum factor 30 or higher with a high ultraviolet A rating, reapplied every two hours and after water or sweat, plus clothing, a hat, sunglasses and shade.
• •Do not rely on sunscreen alone, and build reapplication into training and travel.
• •Doxycycline and other medicines can cause photosensitivity, so increase protection but do not stop essential malaria prophylaxis without advice.