What Is a Sunburn?
A sunburn is a burn of the skin from ultraviolet (UV) radiation, either from the sun or UV-emitting lamps (tanning saloons). It appears as a reddened and/or swollen, itchy, burning skin.
A sunburn occurs when sun exposure exceeds ability of skin pigment melanin to protect the skin.
On the cellular level, there is formation of sunburn toxins that cause skin inflammation, and decrease of Langerhans’ and mast cells (important immune cells).
Symptoms of a Sunburn (First-Degree Burn)
Symptoms of a sunburn are not apparent immediately after the sun exposure. They may appear within 30 minutes, but usually only after 2-6 hours, and may continue to develop for 6-48 hours before starting to subside. Sunburn usually affects only epidermis (first-degree burn). Symptoms may include:
- Redness (erythema)
- Swelling (edema)
- Skin feels warm to the touch
- Skin peeling – usually starts 3rd-8th day
- In severe cases, blisters, chills and fever may appear
It may take few days to three weeks for sunburns to heal completely.
Symptoms of Long Term (Years) Exposure to Sun
Repeated skin exposure to sun may cause:
- Deep wrinkles
- Dry thin skin
- Spider nevi – small red/purplish vessel nets on the face and upper trunk
- White spots on arms and legs
- Brown spots – solar lentigines
- Solar (actinic) keratoses – rough scaly changes of various colors (whitish, red, brown…) that may develop into cancer
- Skin cancer: basal or squamous cell carcinoma, or melanoma – these may itch, and especially melanoma is fast growing and life threatening cancer that metastases in other organs early.
What Causes a Sunburn?
Ultraviolet rays UV-A and UV-B cause a sunburn. These rays come from the sun and UV emitting lamps like in tanning saloons. Antibiotics, anti-psoriasis and anti-acne drugs may make skin photo-sensitive and increase the possibility to get sun-burn.
Risk Factors to Get Sunburn
Risk factors for getting sunburn include:
- People with pale white skin (low amount of melanin in the skin), blue eyes and blond hair may develop sunburn after only 15 minutes of sun exposure
- Regions around equator
- Time between 10 am and 2 pm
- Prolonged exposure to sun
- High altitude; amount of UV rays doubles every 300 m
- Sun reflecting surfaces – any white surface (sand), water surface (sea, lake), and snow
- Diseases like albinism (complete lack of melanin production), vitiligo (small white patches of skin without melanocytes), psoriasis, systemic lupus erythematosus (SLE), xeroderma pigmentosum, and porphyria make skin susceptible for a sunburn.
- Drugs like some antibiotics (tetracycline), and anti-acne drugs may cause photo-sensitivity – vulnerability of skin to get a sunburn.
How to Prevent a Sunburn?
Seriously consider this:
- Avoid sun, especially between 10 am and 4 pm
- Wear wide hat, long pants and shirts with long sleeves
- Apply a cream (sunscreen) with a sun protecting factor (SPF) at least 30. Be aware that there is no cream that can completely protect the skin from the sun. Sunburn protective substances are vitamins C and E, carotenoids (beta-carotene), and Polypodium leucotomos (see below).
NOTE: There is no scientific proof that getting some skin tanning before ‘serious’ sun exposure can protect someone from sunburns (2). Only sunscreens can provide some skin protection.
How to Ease a Sunburn Before it Develops?
If you expect you will develop a sunburn, you may take the following steps to ease the symptoms:
- Get out of the sun
- Immediately take two aspirins (or other anti-inflammatory drug such as ibuprofen), and then two every four hours. Aspirin should be avoided in children with fever.
- Take a cool shower or bath, or apply cold compresses soaked in water. Do not rub the skin when you are drying yourself with the towel.
- Polypodium leucotomos extract from a tropical plant grown in Middle and South America is photo-protective and reduces skin inflammation. It is currently available in New Zealand as an oral supplement, combined with beta carotene and green tea extract.
How to Treat a Sunburn?
Sunburns are actually not treated, but their developing may be limited and symptoms eased.
- Follow prevention measures mentioned above, even when a sunburn has already developed.
- If there are no blisters, apply moisturizing cream, Aloe vera lotion, or corticosteroid cream on exposed parts of the skin 2 times a day (corticosteroids are not active after 24-48 hours after a sunburn appearance).
- If there are blisters, cover the skin with a dry sterile gauze to prevent infection. Do not break the blisters. When blisters break spontaneously, cover them only if they are irritated by clothes, otherwise leave them as they are. Cream with silver sulfadiazine (1%) may be used to prevent bacterial infections in burns with broken blisters.
Precautions in Therapy of a Sunburn
- Aspirin should be avoided in children with fever (to prevent a rare but serious Reye’s syndrome)
- Lotions with local anesthetics (benzocaine, lidocaine), since you may develop allergy to them
- Do not apply petroleum jelly (Vaseline), butter or other home remedies on the skin, since they slow the healing.
- Creams containing PABA should be avoided due to high rate of allergic reactions they cause.
- If blisters develop, do not use corticosteroid creams, since they increase the risk for infection.
- No real ’sunblock’, ‘all-day protection’ or ‘waterproof’ creams exist. A sunscreen should be re-applied several times a day, especially after swimming or sweating.
- What Is a Good Sunscreen?
- Safe Sunscreen Ingredients
- Harmful Sunscreen Ingredients
- Natural and Organic Sunscreens
- Types of Skin Rashes
- Itchy Skin – Causes
- Itchy Skin – Diagnosis and Treatment
- About sunburns (nlm.nih.gov/medlineplus)
- Skin tanning is not protective against sunburns (mayoclinic.com)
Article reviewed by Dr. Greg. Last updated on February 17, 2010