Controlled exposure to sunlight provides numerous benefits to both your body and sense of well-being. Sunlight helps your body produce vitamin D, lowers blood pressure and stimulates production of serotonin, the “feel good” hormone. However, overexposure to the sun can cause a number of problems with no offsetting benefit. One potential problem is sun poisoning. Sun poisoning is an allergic reaction to the ultraviolet, or UV wavelengths, in the sun.
You can define sun poisoning using different terms. MayoClinic.com calls it polymorphous light eruption while the numerous medical dictionaries, as well as the University of Maryland Medical Center define it using the term photodermatitis. Whichever term you prefer to use, all agree that sun poisoning is an abnormal skin condition caused by a reaction in your immune system that triggers an allergic response to UV light.
While overexposure to sunlight is a major cause of sun poisoning, there are additional contributing factors. Race and genetic makeup can leave you more susceptible. MayoClinic.com notes that sun poisoning is the most common type of sun allergy in light-skinned or Caucasian people. Medical conditions such as pellagra and certain medications that make your skin more sensitive to light can also be contributing factors.
The most common and usually first symptom is the appearance of a red rash. While you may see this rash develop in areas exposed to sunlight, it may also develop in unexposed areas as well. MayoClinic.com defines the most common locations as the front of your neck, chest, arms and thighs. Burning and itching may accompany the rash, along with bumps that blister and swell. Flu-like symptoms such as chills, headache and nausea are also common. Symptoms can appear within minutes or hours of exposure and last one week or more.
When you expose your skin to sunlight, melanin present in the upper layers of your skin normally prevents damaging UV rays from penetrating to sensitive skin cells in underlying layers. When not enough melanin is present, or contributing factors limit the protective action of melanin, your immune system senses the intruding UV rays and reacts. The resulting rash and related symptoms are the result of this reaction.
You can treat a mild case of sun poisoning on your own but should see your doctor if symptoms get worse or do not clear up within a week. At home, preventative treatments include staying out of direct sunlight, wearing sunscreen and protective clothing if you must be outside, and using a cool compress or applying anti-inflammatory creams on affected areas. Treatments your doctor may prescribe include a corticosteroid cream or, if the reaction is severe, azathioprine, a drug that works to suppress immune system responses.
Tanning beds and lamps can also cause sun poisoning. Such tanning devices should be avoided, according to the University of Maryland Medical Center.
The University of Maryland Medical Center website also warns that if your predisposition to sun poisoning is genetic, your chances of developing skin cancer increase with repeated occurrences of this condition.