A dozen fairly common viruses and bacterial infections can cause a maculopapular rash, which is characterized by a dark pink sea of flat or raised spots and lesions that can spread over any area of skin. However, the main reason people get this type of rash is after an allergic reaction to any number of prescription drugs or foods. After ruling out more serious infections, a doctor will try to see what is causing this adverse reaction and then remove it from the patient's diet.
According to the EB Medicine website, a maculopapular rash is the most common type of rash treated in emergency rooms around the world. Its most common cause is an allergic reaction to drugs. Medical experts have categorized this type of rash as "morbilliform" because it looks like the patient might have measles. These mottled areas may be concentrated on one part of the body or may be randomly scattered from head to toe.
A maculopapular rash can be caused by drugs used to treat cancer, boost immunity, or relieve pain, including sulfonamides, dapsone, and phenytoin. Since it might not be a drug that caused the disorder, doctors will first rule out other possibilities. A topical reaction could be occurring, or any number of serious disorders. According to EB Medicine, a drug allergy is likely to cause a skin rash that is confined to a certain area, but so does Lyme disease, typhoid fever, rubella, and several other viral infections. However, when a maculopapular rash is randomly spaced around the body, it could be due to half a dozen other conditions, such as syphilis, foot-and-mouth disease, or Rocky Mountain spotted fever.
If a doctor determines that a drug may be causing a maculopapular rash, it will not be taken again. An alternative medication may be prescribed or the course of treatment may change dramatically. Most of these conditions will subside as soon as the offending agent is removed. Often, if itching accompanies the rash, an antihistamine is prescribed until the redness subsides.
It is important to understand the other symptoms that may accompany a maculopapular rash. This outbreak could be present with a fever or severe swelling of the lymph nodes. When experiencing a severe allergic reaction, called anaphylaxis, all of these symptoms can lead to shock and even death, if left untreated.