Why does it happen?
Sunburn occurs due to an inflammatory reaction of the skin when exposed to ultraviolet (UV) radiation (especially UV-B exposure). UV exposure comes from the sun, tanning beds, and some types of lamps. Most sunburns are “first-degree” or superficial sunburns. Other causes and associations include use of photosensitizing drugs and heavy alcohol use.
Who is at risk?
Anyone can be at risk due to sun exposure. However, people who spend a lot of time outdoors – like farmers and outdoor athletes – are most prone to significant ultraviolet exposure. In the United States, about 1 out of 3 people experience a sunburn each year. The greatest risk of sunburn comes from those living closer to the equator and higher in altitude. Additionally, lighter skinned people are more prone to getting sunburns.
Symptoms may include redness in exposed areas, skin peeling and scaling, pain, tanning, rash, blistering, fluid leakage. The patient may also experience fever, chills, malaise, nausea or vomiting.
Sunburn is categorized by the degree, or extent of the burn, with first-degree burns being the least damaging and third-degree burns being the most damaging.
|Degree of Sunburn||Symptoms|
|First Degree||Tenderness, Redness, Peeling Skin|
|Second Degree||Swelling, Blistering, Deep redness, Surface skin is wet to the touch, Fever, Nausea|
|Third Degree||Severe blistering, Skin fissuring, Surface skin appears “charred”, loss of sensation, Potential loss of affected body part|
Signs of sunburn may not be visible for several hours. It often worsens between 24 to 36 hours and improves after 3 to 5 days. Ultraviolet radiation causes direct damage to cellular DNA, causing inflammation and programmed death of skin cells. Histamine, serotonin, and cytokines are a few of many molecules that are released after UV exposure. Tanning may occur due to an increase in skin pigmentation. Immediate pigment darkening occurs with changes to melanin, while delayed tanning occurs in response to increased synthesis of melanin in the epidermis. A severe sunburn may lead to dehydration and eventually shock. Symptoms of shock, such as fainting, low blood pressure, and major weakness require immediate medical attention. The skin usually heals itself by peeling from the topmost damaged layers.
Diagnosis and Differential diagnosis
Sunburn is often diagnosed by the physician by asking if you had any recent periods of prolonged sun exposure, especially without the use of sunscreen.
Differential diagnoses include: acute intermittent porphyria, allergic contact dermatitis, atopic dermatitis, cellulitis, chemical burns, drug-induced photosensitivity, thermal burns, exfoliative dermatitis, heat stroke, systemic lupus erythematosus, xeroderma pigmentosum
If you experience sunburn, run the burnt area under cool water or bath. Use a moisturizer or aloe vera to retain moisture and soothe the burn. Avoid touching or applying pressure to the burnt area, especially if there are blisters.
Future prevention is important for avoiding sunburns. It is necessary to wear sunscreen every day, even when you do not spend a lot of time outdoors. Most American sunscreens use SPF ratings and Korean sunscreens use PA ratings (PA+, PA++, PA +++, PA++++). A higher SPF number or more “+” after PA corresponds to more UV protection and longer time before tanning occurs. Make sure to reapply sunscreen to skin every 2 hours or as directed by the product. Wearing light-colored, tightly woven, and long-sleeved clothes in addition to using sunscreen will also help reduce risk of sunburn.
Most sunburns have an excellent prognosis and heal on their own. However, you should visit a dermatologist if you are experiencing a lot of pain or your burn appears worse. With aggressive burns, fluid resuscitation and skin care are important.
American Academy of Dermatology – How to Treat SunburnJohns Hopkins Medicine – Sunburn
Walker SL, Hawk JL, Young AR. Acute effects of ultraviolet radiation on the skin. Freedberg IM, ed. Fitzpatrick’s Dermatology in General Medicine. 6th ed. New York, NY: McGraw-Hill; 2003. 1275-1282.
Matsumura Y, Ananthaswamy HN. Toxic effects of ultraviolet radiation on the skin. Toxicol Appl Pharmacol. 2004 Mar 15. 195(3):298-308. [Medline].
Walsh LJ. Ultraviolet B irradiation of skin induces mast cell degranulation and release of tumour necrosis factor-alpha. Immunol Cell Biol. 1995 Jun. 73(3):226-33. [Medline].
Narbutt J, Lesiak A, Sysa-Jedrzejowska A, Boncela J, Wozniacka A, Norval M. Repeated exposures of humans to low doses of solar simulated radiation lead to limited photoadaptation and photoprotection against UVB-induced erythema and cytokine mRNA up-regulation. J Dermatol Sci. 2007 Mar. 45(3):210-2
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