Common allergens include pollen, dust, food, animals and insects, mold, certain medication, and latex. According to the American Academy of Allergy, Asthma & Immunology, the amount of school children around the world affected by allergic reactions to one or more common allergens is quickly approaching between 40 to 50 percent. Here are five of the strangest allergies people actually suffer from:

1. Water – People with aquagenic urticaria experience itchy white or red lumps on a part of their body that is exposed to direct contact with either hot or cold water. An allergic reaction to water is extremely rare affecting one out of every 23 million.

2. Exercise – Allergy experts believe exercise-induced anaphylaxis is caused by eating a food that causes an allergic reaction and working out directly after. Symptoms that occur during physical activity include shock, a severe drop in blood pressure, and in some cases even death.

3. Cold – An allergic reaction to cold temperatures, also known as cold urticaria, is characterized by redness, itching, swelling, and hives caused by the release histamines into the body. People affected by this allergic reaction can experience a drop in blood pressure and even death if they are exposed to cold temperatures for an extended period of time including cold water and beverages.

4. Semen – People with a semen allergy can experience hives, itching, and difficulty breathing caused by proteins in their partner’s semen. Women affected by a semen allergy may require artificial insemination in order to become pregnant.

 5. The Sun – Allergic reactions to the sun go well beyond a typical sunburn. People who are allergic to the sun can develop itchy red bumps, rashes, or blisters after being exposed to sunlight. The most common sun allergy, polymorphic light eruption, is also known as sun poisoning.