Sunburn is reddening of the skin caused by exposure to the suns ultraviolet (UV) light at wavelengths between 290 and 320nm. It may range from a mild, asymptomatic redness to a more severe reaction with redness, tenderness, pain, swelling and sometimes blister formation. Mild reactions take place anywhere from 6 to 12 hours after exposure, and peak in intensity within 24 hours. It usually diminishes over a period of 3 to 5 days. It then goes on to a tan over a period of days. More intense reactions peak on the 2nd day at which time large blisters may occur in the more severely affected areas. After several days the redness and swelling subside and are followed by peeling of the skin. If the sunburned area is extensive, symptoms such as nausea, malaise, headache, fever, chills and delirium may occur. Ultraviolet light can also reach the skin through the reflection from snow (80-85%), sand (17-25%), water (5% but when directly overhead up to 100%), sidewalks and grass. On a bright cloudy day with a thin cloud cover it is possible to receive 60-80% of the UV light that is present on a bright clear day.

Measures that reduce the exposure to strong sunlight are important for infants and children as well as fair skinned individuals. Outdoor activities could be timed to avoid the peak exposure times of between 10h00 to 14h00. Wearing caps and light textured materials such as T shirts will give only partial protection to the sun. Infants should be kept under an umbrella at the beach and strollers should be walked in a direction towards the sun.

Sunscreens are topical preparations designed to protect the skin from the effects of ultraviolet light. They act to ‘screen out’ the light at a particular wave length or act as a barrier that impedes or blocks the passage of UV light. Zinc oxide ointment is an example of the latter. Sunscreens are classified on the basis of their ‘sun protective factor’ (SPF). A rating of 4 is limited protection. A rating of 8 is maximum sunburn protection (allows tanning and limits sunburn). A rating of 15 gives ultra protection (absorbs burning as well as tanning rays). Anything higher than this is usually unnecessary. The pitfall with most sunscreens is that they need to be applied frequently during the day because they loose their ability to block the suns rays (most certainly after swimming). Some sunscreens are water proof and do not have to be reapplied to the skin as frequently as the others.

The treatment of sunburn is as follows:

• Cool compresses or cool tub bath (Aveeno oatmeal, baking soda or cornstarch may be added to the bath water).
• Topical cortisone (hydrocortisone 1%) may be applied to the burned areas.
• Anti-inflammatory medication such as ibuprofen may be given.
• A preparation containing aloe may be applied for its soothing and healing ability.

Some countries have Aloe Vera plants growing wild.