Allergic reactions to 14 karat gold earrings and other metal jewelry are fairly common. Signs and symptoms can appear soon after exposure to new jewelry, or may develop over time as the metal on your earrings wear down.

Juniper trees are a common source of allergies due to the pollen they create. Individuals with a juniper allergy are said to have seasonal allergies, meaning the symptoms flare up only when the tree is producing pollens.

Your thyroid gland produces hormones that help regulate your energy, metabolism, moods and body temperature. After you eat goitrogens, substances that occur naturally in various foods, a healthy thyroid will compensate by releasing more hormones than usual.

Itchy skin after eating tomatoes may be more common than you think. The acidity from the tomato can cause skin irritation and can even cause allergic contact dermatitis.

About 6.6 million Americans are allergic to seafood, which can include shellfish and other types of fish such as tuna, according to a study in the July 2004 issue of the “Journal of Allergy and Clinical Immunology.” Seafood allergy is lifelong, and if you are allergic to tuna you may also have allergies to other fish.

Pollen is one of the most common types of allergens. Grains of pollen are expelled into the air from trees, grasses and weeds in different regions and at different times of the year. Coughing is one of many symptoms of pollen allergy, which can be relieved with proper treatment.

Croup is a medical condition characterized by difficulty breathing and a distinctive cough caused by constricted airways. Croup, which usually affects children who are 5 years old or younger, results from inflammation and swelling of the larynx and trachea.

If you suffer from gluten intolerance or celiac disease, you must eliminate all sources of gluten from your diet. Gluten is a protein in wheat and other grains. Following a gluten-free diet takes some practice because not every food or food ingredient that contains gluten is obvious.

Grass allergy rates in the top three pollen allergies along with ragweed and birch tree allergies. People with pollen allergies develop allergic rhinitis, a reaction triggered by the pollen of certain plants as it is released into the air.

Histamine naturally occurs in the body and is released during allergic reactions and times of stress. Histamine is also present in certain foods and is broken down by the enzyme diamine oxidase.

Toddlers are no strangers to minor health issues such as colds and flu, as their immune system continues to grow and develop. Stomach pain also is a common toddler complaint, and while the majority of the time it is nothing serious, a more ominous problem such as a bowel obstruction is possible.

Lactose intolerance may cause stomach upset and other intestinal problems when you consume dairy products such as milk, cheese and yogurt. If you have an allergic reaction to a component in dairy, you could have other symptoms that may include swollen eyelids.