How To Recognize the Common Signs of Lupus

Lupus is an autoimmune disease that affects different parts of the body. Systemic lupus erythematosus (SLE) is the most common type of lupus, according to Johns Hopkins Medicine.

Lupus can take years to diagnose because the symptoms of this autoimmune disease can masquerade as other illnesses.

Lupus isn't rare—around 1.5 million Americans, mostly women, are affected, according to the Lupus Foundation of America. Lupus can easily be misdiagnosed as rheumatoid arthritis or as another condition. Also, symptoms that seem like lupus can sometimes be due to a virus.

According to the Lupus Foundation of America, if a patient has at least four of these 11 lupus symptoms (though not necessarily all at the same time), they may be diagnosed with lupus.

Butterfly Rash

A persistent rash across the cheeks and nose, in the general shape of a butterfly, is "very characteristic" of lupus, said Gary Gilkeson, MD, a professor of medicine at the Medical University of South Carolina in Charleston.

While about 30% of lupus patients typically get this butterfly rash, it can also be due to rosacea or other skin conditions, and this symptom alone is not enough to diagnose lupus.

Sunlight-triggered Rash

Exposure to sunlight or other ultraviolet light sources (even artificial) can worsen a lupus patient's butterfly rash. It can also trigger sores on other body parts, usually in sun-exposed areas, leading to joint pain and fatigue. Fair-skinned patients tend to be most affected.

However, this symptom can be overused in diagnosis: "It is a confusing one," said Dr. Gilkson. "A lot of people say that they are sun-sensitive."

Mouth or Nasal Sores

Mouth ulcers are one of the most common symptoms of lupus. But what makes a lupus mouth ulcer unique, said Dr. Gilkeson, is that it usually comes pain-free. And rather than developing on the sides of the mouth or gums, these sores typically reside on the roof of the mouth. Lupus-related ulcers can also appear inside the nose.

Joint Swelling

Joints that are red, warm, tender, and swollen may be a sign of lupus. Aching and stiffness alone aren't enough; the joints have to be affected by arthritis and these other "cardinal signs of inflammation," says Michael Belmont, MD, director of the lupus clinic at Bellevue Hospital and medical director at the New York University Hospital for Joint Diseases in New York City.

Dr. Belmont said that at least two joints, typically smaller ones, have to be persistently affected for at least six weeks for the symptom to qualify as one of the four diagnostics.

Inflammation of the Lining of the Heart or Lung

Inflammation of the lining around the heart (pericarditis) or lungs (pleuritis) can be a sign of lupus. But both conditions are more commonly due to viral illnesses, said Dr. Belmont.

Even though the inflammation rarely affects the functioning of the heart or lungs, it can cause sharp chest pain—especially when a person is coughing or taking a deep breath—and may occasionally spark shortness of breath.

Urine Abnormalities

Microscopic blood cells and proteins that are not normally found in urine can appear in the urine samples of some lupus patients. Yet again, a lot of other illnesses can be to blame, including urinary tract infections and kidney stones.

A healthy kidney filters proteins out of the blood as it creates urine, said Dr. Belmont. But if the kidney is inflamed and not functioning properly, as can be the case with lupus, proteins may sneak into the urine.

These abnormalities don't usually cause symptoms. However, if the loss of protein (specifically albumin) is substantial, the feet may swell. And if someone has progressed to kidney failure, they might have some nausea and weakness.

Seizures or Psychosis

Lupus can trigger various brain and nervous system problems, including nonspecific symptoms like anxiety, headaches, and vision problems. However, two additional concrete symptoms make the list: seizures and psychosis, which is a break from reality and can include delusions and hallucinations.

For less specific symptoms like headaches, it can be difficult to tease out whether they are caused by lupus, the medications used to treat it, or the stress of living with the disease.

Anemia

Anemia, or an inadequate number of circulating red blood cells, is very common, especially in lupus's target population: women. Iron deficiency anemia, for example, is frequently present during menstrual cycles. More specific to lupus, however, is a disorder called hemolytic anemia.

"It's not just a low blood count. The condition is actively destroying the cells," explains Dr. Gilkeson, adding that certain lab tests can tell the types apart.

Discoid Rash

A discoid rash is a "fairly classic" lupus symptom, said Dr. Gilkeson. The disc-shaped patches appear red and raised and typically develop on the face, scalp, and neck. They often leave scars.

While relatively common in SLE, discoid rashes can also stand alone in diagnosing discoid lupus, a type that only affects the skin.

Positive ANA Test

The antinuclear antibody (ANA) test is the go-to screening test for lupus, according to the National Library of Medicine. If the result is negative, said Dr. Gilkeson, you can "almost guarantee" that a patient doesn't have lupus. On the other hand, a positive result is much less clear; 90 to 95% of people who have a positive ANA test don't have lupus.

ANAs are proteins the body makes that can attach to DNA and other substances inside cells. But just because they are present in the body doesn't necessarily mean they will attack these substances. These antibodies are found in at least 5% of the general population, so "many more people walking around with ANAs who are perfectly healthy or have some illness that has nothing to do with lupus," said Dr. Belmont.

Other Antibody Tests

To unravel which people with positive ANA tests have lupus, additional blood work can be done. Healthcare providers look for other potentially troublesome antibodies, so they will test for anti-double-stranded DNA and anti-Smith antibodies. Anti-Smith antibodies are ribonucleoproteins found in the nucleus of cells, found almost exclusively in people with lupus, according to Johns Hopkins Medicine. These tests are less likely to be positive unless a patient has lupus. However, a person with negative test results could still have lupus, even though this is not so in the case of ANA tests.

"These confirmatory antibodies are very critical to the accuracy and reliability of the diagnosis," said Dr. Belmont. The series of tests, combined with the ANA, added Dr. Belmont, will usually provide a fairly reliable answer.