How Does Your Doctor Diagnose Lupus?

Lupus is a long standing disease and complex enough to make it difficult to diagnose. Some of the symptoms of Lupus mimic other diseases like Rheumatoid arthritis. That is why Lupus is called a “great imitator.” Symptoms of Lupus come, go and reappear. Hence it may take years to diagnose Lupus. There is no single lab test till date which can surely diagnose a person affected with Lupus.

Your doctor may need the following to diagnose Lupus:

    • Physical signs such as swollen joints.
    • Lab reports such as protein in urine.
    • Tests such as skin biopsy which reveal signs of the disease.
    • Medical history and family history: History of illness that you and your family have suffered so far. A detailed description of medicines you take.
    • Specific tests to rule out other diseases.  

Doctors use 11 criteria of Lupus suggested by the American College of Rheumatology to diagnose Systemic Lupus Erythematosus/ SLE. Four or more of the following needs to be present to diagnose SLE:

1.      Butterfly Shaped Rash

A rash is seen on the face, covering the bridge of the nose and adjacent cheeks in the shape of a butterfly. This rash leaves a scar when it disappears.

2.      Discoid Rash

Raised red patches are seen on the skin.

3.      Sensitivity to Light

Skin sores are formed on parts that are exposed to the sun.

4.      Kidney Disease

Excess protein is excreted in the urine. Cellular casts are also seen. Casts are cylindrical structures present in urine and are visible through a microscope. Casts that are composed of red blood cells is an abnormality found in diseases such as Lupus.

5.      Arthritis

Inflammation of joints is called arthritis. It involves 2 or more joints in Lupus. Swelling, warmth, pain, redness and difficulty in moving are the signs of inflammation. In arthritis caused by Lupus, surrounding bones are not destroyed like in other forms of arthritis.

6.      Pericarditis/ Pleuritis

Inflammation of the lining around heart is called Pericarditis. Inflammation of the lining of lungs is called Pleuritis.

7.      Ulcers in the Nose and Mouth

Ulcer occurs when the lining of the skin erodes while exposing the underlying tissue. In Lupus, ulcers formed in the nose and mouth are painless.

8.      Blood Disorder

Reduced cell count is seen in Lupus. Red blood cells, white blood cells and platelets all may be reduced in Lupus.

9.      Nerve Disorders

Seizures are when the body shakes suddenly, rapidly, unintentionally and uncontrollably. Psychotic disorders such as depression are also common in Lupus.

10.  Immune Disorders

Immune system protects the human body against foreign invaders such as bacteria and germs. It forms certain proteins called antibodies which attack the invaders. In Lupus, antibodies are formed against self components such as DNA, the basic coding structures of the human body.

11.  A Positive ANA Test

A positive Anti Nuclear Antibody test shows that your body is generating antibodies against itself. It is one of the 11 criteria for diagnosing Lupus but ANA is also positive in other cases.

While the above is about diagnosing systemic lupus erythematosus, here’s a note on less severe forms of Lupus:

Cutaneous Lupus:

This form of Lupus affects only the skin and not any other part of the body. Skin rashes remain for days or years.

Drug Induced Lupus:

In certain cases, medicines are the culprit. They trigger Lupus which exhibits relatively mild symptoms. It goes away once the medicines causing the condition are stopped.

Your doctor may advice 7 tests to diagnose Lupus:

1.      Blood Count:

Complete blood count measures the number of cells present in blood: Red blood cells, white blood cells and platelets. It also measures protein and haemoglobin in blood.

Anemia/ lack of red blood cells is common in Lupus. Platelets and white blood cells are also likely to be reduced in Lupus.

2.      ESR / Erythrocyte Sedimentation Rate:

This test measures the rate at which the red blood cells settle down at the bottom of the test tube. Higher rate indicates the chances of Lupus.

3.      Biopsy:

Kidney biopsy is necessary in certain cases.

A long, fine needle is inserted into the kidney and a small portion of kidney tissue is taken out.

It is then examined under a microscope to know the amount of inflammation and the extent of scarring in kidneys.

4.      Urine Analysis:

Excess protein is excreted in urine when kidneys are damaged.

Blood in urine, foamy appearance of urine and the presence of cell casts (cells in urine) indicate kidney damage.

5.      ANA Test:

A positive Anti Nuclear Antibody test as mentioned before may indicate Lupus.

6.      Chest X-ray:

This will check if Lupus has damaged the lungs. The lining of the lungs get inflamed and fluid-filled.

7.      ECG:

Echocardiogram checks the abnormalities in heart beat and valves.

If symptoms develop simultaneously, it could be easier to diagnose Lupus but if symptoms develop slowly and inconsistently, it will be difficult to diagnose. Be sure to see your doctor whenever you develop a new symptom. Early diagnosis prevents permanent damage to your organs.

The Importance of Diagnosis

The above tests provide a good insight into the present condition of the patient. These however, can only be done if the patient understands the symptoms of lupus. If you notice two or three related symptoms which are a notch different from the ordinary, it becomes your duty to take care of your heath and to get a thorough heath check up done. The doctor can prescribe blood tests and other sample collections, but nothing works well if the patient is unwilling to cooperate. Diagnosis is the first step towards treatment. Hence practice care and precaution and report any symptoms immediately. While milder dosages can work wonders initially, they might not have the same impact during later stages. Inconsistency of manifestation makes Lupus difficult to handle but try and make it relatively easy to manage.