Dermatology Questions? Ask an Online Dermatologist.
They are hives. You don't need to worry about them. Take over-the-counter antihistamine such as Allegra and apply over-the-counter 1% hydrocortisone cream.
There are many causes such as foods, medications, common allergens include pollen, animal dander, latex and insect stings, environmental factors including heat, cold, sunlight, water, pressure on the skin, emotional stress and exercise, underlying medical conditions including immune system disorders such as lupus, some types of cancer such as lymphoma, certain thyroid conditions, and infections with bacteria or viruses such as hepatitis, HIV, cytomegalovirus or Epstein-Barr virus, and so forth.