Call your primary care doctor or a dermatologist if you have:
An itchy rash that does not respond to over-the-counter treatments
A rash that involves large areas of your body, including parts that are covered by clothing
A persistent rash that covers sun-exposed areas of your face, especially if you are a woman or a person of American Indian heritage
Abnormal bleeding under the skin in sun-exposed areas
Call for emergency help immediately if you suddenly develop hives together with swelling around your eyes or lips, faintness or difficulty breathing or swallowing. These may be signs of a life-threatening allergic reaction.