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10 extremely unusual allergies

sunshine

Photo: Guillaume Cattiaux/Flickr

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Sun

Much more than the occasional sunburn, a sun allergy is an immune system reaction to sunlight that often manifests itself as an itchy rash, headache and nausea, but can also cause symptoms as severe as blisters and bleeding under the skin. In extreme cases, just a few minutes of sun exposure can cause a reaction, making it essential for those affected to stay out of the sun and protect their skin with sunscreen.