Sunburn and Sun Poisoning

What is sunburn?

Sunburn is an inflammation of the skin that is caused by overexposure to ultraviolet (UV) radiation from the sun. A similar burn can follow overexposure to a “sun” (tanning) lamp. UV radiation can also damage the eyes, although no surface burn is apparent.

Can sunburn cause permanent damage?

Yes. Sunburn early in life increases the risk of developing skin cancer later on. Repeated overexposure to ultraviolet rays can also scar, freckle, dry out, and wrinkle the skin prematurely. In addition, frequent overexposure to ultraviolet rays can increase the risk of developing eye cataracts and macular degeneration, a leading cause of blindness.

What is UV light?

UV light is radiation energy in the form of invisible light waves. UV light is emitted by the sun and by tanning lamps.

The sun discharges three types of ultraviolet radiation:

1. ultraviolet A (UV-A),

2. ultraviolet B (UV-B), and
3. ultraviolet C (UV-C).

Only UV-A and UV-B reach earth. (UV-C does not penetrate the earth’s upper atmosphere.)

Although research has long implicated UV-B as the most likely form of UV radiation to damage the skin and cause skin cancer, recent studies suggest that UV-A can also be dangerous.

Tanning lamps also produce UV-A and/or UV-B. These artificial rays affect the skin in the same way as do UV-A and UV-B from the sun.

When and where are UV rays most intense?

UV rays are most intense at noon and the hours immediately before and after (between 10 a.m. and 3 p.m.), particularly in the late spring, summer, and early autumn. Although they are less concentrated at other times of the day and year, UV rays can still damage the skin and eyes - even in the dead of winter and on cloudy or rainy days.

UV rays also increase in intensity in relation to altitude and latitude. The higher the altitude, the greater is the concentration of UV rays. Likewise, the rays are more powerful the nearer the latitude to the equator.

UV rays “bounce” off reflective surfaces - including water, sand, and snow. Thus, a skier, swimmer, fisherman, or beachcomber may be bombarded with UV rays from above and below.

What are the symptoms of sunburn?

• First, the skin becomes red, tender and hot.

• Touching or rubbing the skin causes pain.
• Because heat triggers fluid loss, a sunburn victim can also become dehydrated.
• For several days after exposure, the skin may swell, blister, and peel. Some sufferers develop welts or rashes.

The symptoms of sunburn can be mild, moderate, or severe, depending mainly on the following:

1. The skin type of the person affected. (more detail to follow later in this article)

2. The time, length, location, and altitude of exposure.
3. Medications the person has been taking (sun-sensitizing drugs that may increase a person’s susceptibility to sunburn).
4. Skin preparations the person has been using.

Symptoms of severe sunburn (sun poisoning)

In severe cases of sunburn, the individual may experience (severe cases of sunburn require emergency treatment):

• fever,

• nausea,
• chills,
• dizziness,
• rapid pulse,
• rapid breathing,
• dehydration, and
• shock with loss of consciousness.

What first-aid measures should be taken with sunburn?

If symptoms of severe sunburn are present, the patient should contact their primary healthcare provider, urgent care facility, or Emergency Department. While awaiting treatment, the affected person should not drink cold water, which can trigger chills. If compresses are applied, they should be dipped in cool or tepid water, not cold water.

If the symptoms of sunburn are mild or moderate, the patient may drink plenty of water to replenish the fluid lost from the sunburn and to avoid dehydration. Those affected may then do any or all of the following:

• Apply dampened cloths or compresses to reduce the heat and lessen the pain;

• Soak in a bathtub of plain, soap-free water (soap can irritate the burn);
• Gently pat the skin dry afterward - do not rub it;
• Apply a soothing cream, lotion, or another preparation approved by a physician or pharmacist;
  • Note that some preparations, in particular those containing benzocaine (Endocaine, Hurricaine), can trigger an allergic reaction, and certain ointments can retard healing by sealing off the skin from the air.
• If blistering occurs, apply a bandage to prevent infection;
• If the discomfort is significant, take a painkiller such as acetaminophen (Tylenol and others) or ibuprofen (Advil, Children’s Advil/Motrin, Medipren, Motrin, Nuprin, PediaCare Fever, and others), and;
• Moisturizing measures with creams or Aloe Vera gel may also help with symptoms of sunburn.

• Is there any medical treatment for sunburn?

  Certain medical treatments have been tried and studied to treat sunburn. However, in general, most remedies have not shown any clinically proven benefit as far as speeding the recovery or reversing the damage. Therefore most of the treatments available are only used to treat symptoms.

  Non-steroidal antiinflammatory drugs (NSAIDs) in oral (ibuprofen, Motrin, Naprosyn, Advil etc.) or topical diclofenac 0.1% gel (Solaraze) forms have shown to reduce redness if applied before or immediately after UVB exposure. This benefit may be diminished after 24 hours. It should be noted that these medications may also help with the symptoms of sunburn such as pain and discomfort.

  Topical steroid creams were also studied, but these did not show any significant improvement. Oral steroids such as prednisone did not prove beneficial and have been associated with some significant side effects.

  Applying Aloe Vera gel to the skin has also not been beneficial in treating the actual sunburn. This, again, may be beneficial in treating the symptoms.

  Other advertised remedies such as topical anesthetics (benzocaine) may help with symptoms of sunburn, however, very little clinical data is available to substantiate their effectiveness.

  Is a follow-up visit with a physician necessary?

  A follow-up visit with a physician is not necessary unless the sunburn was severe (sun poisoning). However, every patient who has suffered a significant sunburn should report the incident to his or her doctor so that the burn can become part of the patient’s medical history. Doing so will alert the physician, during future check-ups, to look closely for symptoms of skin cancer and other problems that sunburn can cause.

• Why does the skin tan after exposure to UV rays?

  The skin contains a pigment called melanin. It colors the skin, imparting the variety of skin tones we all recognize.

  Melanin blocks at least some of the UV rays from penetrating the skin. After repeated or prolonged exposure to UV rays, the skin produces more melanin. Consequently, the skin darkens, or tans, which in turn protects the skin to a certain degree.

  Who is most susceptible to sunburn?

  Persons with certain pigment disorders (such as albinism) and persons with fair skin are at highest risk of suffering a burn. The American Academy of Dermatology classifies skin types into six categories (in terms of susceptibility to sunburn) for skin colors ranging from fair to black. This is called the Fitzpatrick classification. These skin types are as follows:

  Types 1 and 2: High Susceptibility to Sunburn

• Individuals with Skin Type 1 have very fair skin (pale or milky white), blond or red hair, and possibly freckles. Such persons can suffer a burn in less than one-half hour when exposed to summer sunlight at midday. People with Skin Type 1 never tan.
• Individuals with Skin Type 2 have very light brown skin and possibly freckles. They burn in a short time in the sun, although they can achieve a very light tan.

Types 3 and 4: Moderate Susceptibility to Sunburn

• Individuals with Skin Type 3 (called “average Caucasians” by The American Academy of Dermatology) have skin that is slightly more brown than the skin of a Type 2. They can develop a moderate sunburn and a light brown tan.

• Individuals with Skin Type 4 have olive-colored skin. Ordinarily, they develop only a minor sunburn while acquiring a moderate tan.

Types 5 and 6: Minimal or No Susceptibility to Sunburn

• Individuals with Skin Type 5 have brown skin and can develop a dark tan while rarely burning.

• Individuals with Skin Type 6 have black skin and never burn.
• It is often difficult to accurately determine an individual’s skin type simply by looking at the color of the skin. It is best to ask the person how quickly they may burn and how easily they tan. Based on the response to these simple questions, the skin type can be determined.

• Can diseases cause a heightened sensitivity to UV rays?

  Yes. Certain disorders place their sufferers at very high risk of skin damage — including severe sunburn, blisters, and sores — from exposure to UV radiation. The following is a small sample of afflictions that increase the skin’s sensitivity to UV radiation:

• Albinism: Individuals with classic oculocutaneous albinism lack melanin in their skin and eyes — hence, the term “oculocutaneous” (”oculo” for eyes, and “cutaneous” for skin). Without the protection of this pigment, their white skin and pink eyes are both highly sensitive to UV and susceptible to the rays’ damage.
• Systemic lupus erythematosus: Individuals with lupus can have inflamed tissues, including the skin on the face. The “butterfly” rash (or malar rash) of lupus over the cheeks and nose is extremely sensitive to UV rays. In fact, UV-B and UV-A rays can cause lupus to flare. This butterfly rash and its sensitivity to sun is one of common characteristics of lupus.
• Porphyrias: The porphyrias are disorders of specific enzymes that are needed for the metabolism of heme (part of the pigment hemoglobin that permits red blood cells to transport oxygen and carbon dioxide). Patients with these disorders manufacture abnormally large amounts of substances called porphyrins. Stimulation of the excess porphyrins in the skin by the UV rays causes damage and scarring of the skin. This skin damage is a prominent feature of several forms of porphyria including porphyria cutanea tarda, hereditary coproporphyria, variegate porphyria, and, particularly, congenital erythropoietic porphyria.
• Vitiligo: Vitiligo is a relatively common disorder that causes patches of white de-pigmented skin. These patches lack melanin and are extremely sensitive to UV rays.
• Xeroderma pigmentosum: This disorder appears to result from an inherited hypersensitivity to the cancer-causing (carcinogenic) effects of ultraviolet light. Sunlight causes DNA damage that is normally repaired. Individuals with xeroderma pigmentosum have defective inability to repair the DNA after UV damage. Affected individuals are hundreds times more vulnerable to developing skin cancer than other people. Their extreme skin photosensitivity predisposes them to pronounced skin damage and scarring but also to the early onset of skin cancer (basal cell and squamous cell carcinomas and malignant melanoma).

• What kinds of cancer can UV rays cause?

  Overexposure to UV rays can cause three varieties of skin cancer; malignant melanoma, basal cell carcinoma, and squamous cell carcinoma.

  Malignant melanoma

• Malignant melanoma is by far the most dangerous form of skin cancer.
• The current lifetime risk of developing a melanoma is approximately 1/60.
• Melanomas may begin from changes in a pre-existing mole or birthmark, or arise as a brand new mole from otherwise clear skin (de novo).
• Multiple features are more common in melanomas versus regular moles including asymmetry, irregular borders, multiple colors, and size larger than a pencil eraser.
• Melanomas may be black or brown - and sometimes red, white or blue, or a mixture of those colors.
• Melanoma can spread (metastasize) rapidly. If diagnosed early, melanoma is often curable. However, if the diagnosis is delayed, melanoma can spread and may be potentially fatal.

Basal and squamous cell carcinomas

Basal and squamous cell cancers are slow-growing and are far less likely to metastasize (spread to other parts of the body) than melanoma. Both basal and squamous cell cancers can be cured in at least 90 percent of the cases if diagnosed early.

Basal cell carcinoma

• Basal cell carcinomas are flattened, pearly, small bumps with translucent edges and slightly depressed centers.

• They may bleed.
• Usually, they appear on the head, neck, upper trunk, and hands.
• If ignored, these cancers can cause considerable localized damage.

Squamous cell carcinoma

• Squamous cell carcinomas are rough patches or crusty scaly areas on the skin that do not clear up and do not respond to the usual skin creams.

• They may bleed a little.
• They tend to appear particularly on the ear rims, face, lower lip, and hands.
• f ignored, they can spread to other parts of the body.

These conditions are very common and if diagnosed properly and promptly, they are highly curable. Therefore it is very important to have routine skin checks by a trained skin doctor (dermatologist) annually. Annual screening can help in early diagnosis of skin cancer or pre-cancerous conditions that may lead to skin cancer.

How can sunburn and skin cancer be prevented?

The ideal methods of preventing sunburn, and hopefully skin cancer, involve:

1. Limit the amount of time of sun exposure and avoiding the peak sunshine hours of late morning to early mid-day, generally 10 a.m. to 4 p.m.;

2. Wear protective clothing such as a broad-brimmed hat (at least 6 inches), long- legged pants, and shirts with sleeves that cover the arms (thicker fabrics and dark clothing in general protect better compared with light clothing - there are clothing products available that offer “UV” protection);
3. Be aware that sunburn can occur even on a cloudy day (clouds don’t stop the ultraviolet rays), and even when you are in the water;
4. Remember that sand, water, and snow reflect the sun’s rays and increase the chance of burning during beach activities or skiing; and
5. Use a protective sunscreen to minimize the penetration of UV rays. Sunscreens with a skin protection factor (SPF) of at least 15 are recommended for everyone exposed to the sun. It is recommended that light skinned people use a higher SPF when in direct sun. This should be applied several minutes before going into the sun and reapplied often.

How do sunscreens work?

Sunscreens protect the skin by absorbing or reflecting the UV radiation. It is important to realize that many available sunscreens protects mainly against UVB and may not adequately protect against long standing UVA exposure.

Sunscreens may be classified into two groups, physical sunscreens and chemical sunscreens.

Physical sunscreens

• Physical sunscreens act by reflecting and scattering the UV rays (A and B) and thus, limiting their exposure to the skin.

• They include chemicals such as zinc oxide, titanium dioxide, ferric chloride, ichthamnol, and talc.
• Their use has been somewhat limited by their opaque appearance and tendency to stain clothing.
• Current preparations of zinc oxide are more cosmetically acceptable and easier to use.

Chemical sunscreens

• Chemical sunscreens work by absorbing the light prior to reaching the skin.

• Traditionally, these sunscreens have protected mainly against UVB rays.
• Some examples of this group include para-aminobenzoic acid (PABA), PABA esters, salicylates, and camphor derivatives.
• More recently, newer sunscreens have been developed to also absorb UVA such as avobenzone, Mexoryl, dibenzoylmethanes, anthranilates, benzophenones, triazoles, and some camphor derivatives.
• PABA has been essentially phased out of sunscreen preparations because of the high rate of allergic reactions to this chemical.

The most recommended practice is to use a combination of physical and chemical sunscreens for the most adequate protection.

What is SPF?

SPF, or Sun Protection Factor, is the measurement of how well an agent may protect against sunburn. This can be multiplied by the time that it takes to develop mild redness or burning in an unprotected person. For example, if someone develops mild sunburn-related redness in 20 minutes, he or she may develop the same degree of redness in 300 minutes (5 hours) with an SPF 15 sunscreen (15 times 20 minutes) when properly applied.

What is the best way to apply sunscreen?

It advised to apply sunscreen 15 to 30 minutes before expected sun exposure. Reapplication of sunscreen every 1-2 hours is also generally advised. Some experts, however, encourage more frequent reapplication, especially shortly after initial exposure. It is also important to apply sunscreen very liberally; spreading the product too thin may not achieve the desired degree of protection.

SPF 15 sunscreen is the minimum requirement for most individuals. Stronger sunscreens are recommended for people who easily burn in the sun and have longer exposure time in the sun. Water exposure may wash off the sunscreen, so it should be reapplied after the body dries up.

Do sunscreens expire?

Sunscreens may degrade over time or after long exposure to sun and heat. Therefore, the bottle should not be kept in the car or under direct sun exposure for a long period of time. If the expiration date has passed, the product needs to be discarded and replaced with a new one. Sunscreens generally expire or loose their effectiveness after about three years.

Can antioxidants protect against sunburn?

Antioxidants are agents that can prevent certain harmful reactions in the body. The formation of some potentially harmful molecules, called free radicals, is one if these reactions. Antioxidants are natural agents that may prevent or reduce this formation.

Some of sun damage is a result of this reaction. Oral or topical antioxidants (vitamins A, C, and E, and green tea) may theoretically protect the skin against sunburn. Clinical data is not sufficient to support their use instead of or in addition to, traditional sunscreen.

Sunburn At A Glance

• Sunburn may cause permanent skin damage and skin cancer.

• UVB as well as UVA rays may cause damage to skin.
• UV rays may bounce off water, sand, snow, and other surfaces.
• The best way to prevent sunburn is to avoid long exposure to sunlight.
• Sunscreen and sun-protective clothing are important measures to limit sun damage.
• Apply sunscreen before going outdoors, apply it liberally, and re-apply frequently.

Reference: The American Academy of Dermatology