Not all joint pain is arthritis

As a rheumatologist, I’m becoming an expert in evaluating all types of joint pain.  My adult patients are wonderful at describing how their joints feel: burning, stabbing, pressure, stiffness, crushing, aching, throbbing.  Children use more creative language: the joint feels like ice cream, like aliens are poking at them with needles from the inside, like bugs are crawling over them.

Pain in a joint is one of the most common reasons why patients are referred to a rheumatologist, often with the suspicion that the pain is due to arthritis.   Although there are many causes of joint pain, one simple question can help to differentiate between arthritis and most of the other conditions.

Arthritis is a term that refers to inflammation of a joint.  There are two basic types of arthritis: inflammatory arthritis (like rheumatoid arthritis) and osteoarthritis.  It’s easy to see inflammatory arthritis: it causes joint swelling, warmth, redness, and pain. Osteoarthritis, on the other hand,  does not  cause much joint inflammation and usually only presents pain.

So how is one to tell the difference between all of the entities that cause joint pain?   Just ask this question: “when do your symptoms occur?”

Morning symptoms are most common in inflammatory arthritis.  Patients describe significant stiffness in their joints when they wake up.  This is referred to as the “gelling phenomenon,” which occurs because the fluid inside the joint becomes thickened, like a gel, and makes movement difficult.  Patients with inflammatory arthritis have a hard time getting out of bed; it may take them over an hour before their joints begin to feel better.  This stiffness improves as they pursue different activities (when the “gel” is warmed up), but if they sit for prolonged periods of time, their symptoms will return.  One of my patients with active rheumatoid arthritis tells me that in the morning, her hands feel clumsy and weak, and she finds it difficult and painful to button her blouse, open jars for breakfast, or drive to work.  Her symptoms improve later in the day.

In children, who are  rarely able to describe “stiffness,” it is usually the parents who first notice the symptoms of juvenile arthritis (kids get arthritis too!).  Parents say that their child has a limp that is worse in the morning, and improves throughout the day.  They may also notice a swollen knee or ankle.  However, even with a limp and active arthritis, children  usually  continue to do most of their activities,  including sports.  I had a patient with juvenile arthritis affecting her legs, who continued to run cross-country despite active disease.  She would do well in races at “home,” when she was able to warm up well before a race.  However, whenever she went to an “away” race, she became stiff after the long bus ride, and as a result her speed suffered.

In contrast, osteoarthritis and diseases caused by damage to the joint, such as sprains, strains, and fractures, usually present with symptoms that are worse later in the day.  Pain is exacerbated when patients are involved in activities: climbing stairs, running, walking, writing, cooking, cleaning, etc.  When they sit down to rest, pain improves.   In osteoarthritis, the pain is due to joint damage as a result of wear-and-tear.  Osteoarthritis is the kind of arthritis that people usually talk about  when they say that “Aunt Bertha had arthritis of the hips and needed a hip replacement,” or “I can’t play golf with you, Lenny, the arthritis in my back is killing me!”     As you can imagine, this type of arthritis becomes more common as people age, and predominantly affects weight-bearing joints such as the knees, hips, as well as the fingers.  Stiffness is not a predominant symptom in patients that have non-inflammatory causes of joint pain.

Finally, I evaluate patients that have severe pain in multiple joints “all the time.”  These patients don’t have the warm, swollen joints that are seen in inflammatory arthritis.  They  are often young, and don’t have evidence of wear-and-tear, as seen in osteoarthritis.  They weren’t involved in an accident, and they didn’t sustain strains, sprains, or fractures to multiple joints.  How can they have so much pain, if all of their joints look so normal?  This is a topic that we are only beginning to understand.   It appears that some patients develop abnormalities in the way in which their nervous system is wired, and as a result, they experience pain due to abnormal processing of pain signals.  These patients are often given the diagnosis of chronic pain syndrome or fibromyalgia.  The most puzzling aspect of these conditions is that the pain is real–and often excruciating–even though the joint looks normal.  Treatment for these conditions are aimed at correcting the nervous system abnormalities, not at the joint.   This includes aerobic exercise, cognitive behavioral therapy, and medications that help to reduce pain sensitivity.

Take-home points:

  • Inflammatory arthritis (such as rheumatoid arthritis) usually causes joint swelling, stiffness, and pain that is worse in the morning and improves with activity.
  • Osteoarthritis and other causes of joint damage (strain, sprain, fracture) present with pain that worsens with activity, and improves with rest.
  • Pain amplification syndrome and fibromyalgia cause persistent pain without any visible abnormalities to the joint as a result of abnormalities in the nervous system.

What the heck are autoinflammatory diseases?

Autoinflammatory diseases are a relatively new category of illnesses caused by disorders of one arm of the immune system. Many of these diseases are characterized by recurrent fevers, rash, chest and abdominal pain, and evidence of systemic inflammation on blood tests; these manifestations often mimic infectious or other illnesses, and it may take several years for the diagnosis to be made.

Most autoinflammatory diseases are genetic (inherited), start in childhood, and persist throughout adult life. These diseases are often present in several members of a family. Other autoinflammatory diseases appear to be acquired, perhaps due to the interplay of genetic and environmental factors, and can present at any time during childhood or adulthood.

The list of autoinflammatory diseases continues to grow every month.  Here is a list of the autoinflammatory diseases as they stand so far:

Your child with frequent fevers: is it autoinflammatory?

When I was little, I used to get a lot of fevers.  With my fevers, I would develop pain in one or both of my ears, and I felt so drained that I just wanted to be left alone to watch TV (or play Atari).  If my fever spiked in the middle of the night, my parents would soak me in a tub of lukewarm water to lower my temperature (how I hated those baths!).  On the following day, I would visit my pediatrician, who would invariably diagnose me with an ear infection.  He prescribed a delicious bubble-gum flavored antibiotic that my parents kept at the top shelf in the refrigerator (out of my reach so I wouldn’t overdose).  I’m not sure if it was the taste or the active ingredient, but this antibiotic always made me feel better.  After what seemed like the millionth episode of fever, my pediatrician recommended that I get tubes in my ears, and the episodes of fever and ear pain subsided.

Recurrent infections, like those I had when I was a child, are the most common cause of frequent fevers in children.  Usually, these infections are due to viruses, such as the ones that cause the common cold.  Children with colds often develop symptoms attributable to the virus, including a runny nose, nasal congestion, or cough.  Multiple infections, one after the other, are especially common in children attending daycare or school, where they trade viruses like I used to trade baseball cards with my friends.  When I see these the worried parents of these children in my office, I have to remind them that it is normal for a child to have 9-12 colds every year.  Fortunately, these children continue to grow and gain weight without difficulty, and they are healthy between episodes. “As your child grows,” I tell the parents, “his immune system will become better at fighting infections, and the frequency and severity of fevers will diminish.”  Aside from stressing the importance of hand washing among all family members, there is not much that can (or needs) to be done about these episodes. 

However, if the episodes do not clearly match the above description, other diagnoses should be considered.  In this post, I will provide some tips that may help parents and physicians recognize a rare cause of fever in children: autoinflammatory diseases.  The most common autoinflammatory disease in children is called PFAPA, which stands for Periodic Fevers, Aphthous stomatitis (canker sores or oral ulcers), Pharyngitis (sore throat) and Adenitis (enlarged glands in the neck).   This disease usually presents in children less than 5 years of age, and causes episodes of fevers in addition to the features that make up the name of the disease (oral ulcers, sore throat, enlarged glands in the neck).  The fever usually lasts about 4 days, and it recurs at regular intervals, usually every month.  What is unique about PFAPA is that parents can usually predict when the child is “due” to get ill.  The episodes of fever are so regular as to be predictable.  This regularity is rare in most other diseases.  PFAPA is commonly misdiagnosed as frequent Strep infections, and testing for Strep throat is usually negative.  Patients do not readily respond to antibiotics, although their symptoms can disappear with one dose of steroids.

Another clue that the child may have an autoinflammatory disease is that all of the episodes of fever look alike.  For example, if the child always develops abdominal and joint pain with the fevers, then he may have familial Mediterranean fever (FMF).  If, in addition to fever, she always develops a painful rash, muscle pain, and red eyes, then she may have TNF-receptor associated periodic fever (TRAPS).  If he develops fevers, rashes, and joint pain after exposure to cold weather, then the child may have familial cold-induced autoinflammatory syndrome (FCAS).

The length and frequency of fever, associated symptoms, and age at which the fevers began can help differentiate between these (and other) autoinflammatory diseases.   Thus, it is very helpful to keep a fever diary,  specifying the characteristics of each episode.  Because many of these autoinflammatory diseases are inherited (genetic), there is often a history of other family members having similar symptoms.  In addition, it is important to note that some autoinflammatory diseases are more common in people of certain ethnic backgrounds, such as FMF in Sephardic Jews, Turks, and Armenians.

In addition to autoinflammatory diseases, there are some features of recurrent fevers that should warrant a closer look by a child’s  pediatrician.  These include prolonged episodes of fever (more than one week), recurrent fever without symptoms attributable to a viral infection, difficulty growing or gaining weight, or if the child does not return to his baseline between episodes.  Other causes of fever that should be considered in these instances include:

  • Immunodeficiencies: problems in the immune system that makes the child more susceptible to infections
  • Anatomic and metabolic abnormalities: abnormalities in certain organs that make them more prone to infections (like my ears), or diseases such as cystic fibrosis
  • Inflammatory bowel disease: inflammation of the intestines
  • Cancer: such as leukemia or lymphoma

With this knowledge, parents and pediatricians alike can help distinguish between the majority of children that develop recurrent fevers because of frequent viruses, from causes which may require additional workup or treatment.

What the heck is a connective tissue disease?

This week, I was called to evaluate a young man with several aneurysms (ballooning of his blood vessels) and a dilated (widened) aorta.  The medical team thought he had a “connective tissue disease” because a family member also had a connective tissue disease–she had lupus.  Unfortunately, doctors can mean very different things when they talk about a “connective tissue disease;” this is a common source of confusion for doctors and patients alike.  After reading this post, I hope you’ll be able understand the difference.

Connective tissue is the “stuff” that holds your body together.  That is, the bones, ligaments, tendons, cartilage, fat, and “glue” that keeps all your organs in place.  Two very different types of diseases can affect these tissues–you can have problems in MAKING the connective tissues, or these tissues can be ATTACKED by the body’s own immune system.

In the first type of “connective tissue disease,” the body is unable to produce strong connective tissues.  It’s like trying to build a house with weak materials.   If the materials are weak, the house is likely to develop cracks on the walls, holes in the roof, and the whole structure may fall down.  There are many genetic (heritable) diseases that prevent the body from making high-quality building blocks.  Marfan syndrome, for example, is a disease where the body is unable to make high-quality fibrillin (a protein present in many types of connective tissues).  This causes weakness of various parts of the body including the eye (causing lens dislocation), the aorta (causing dilation and potential to rupture), and lungs (causing pneumothorax, or collapse of a lung).   Ehlers-Danlos is another group of diseases where patients have difficulties making collagen, another protein necessary for high-quality connective tissues.  In this disease, patients have loose joints that often dislocate, fragile skin that is unusually “stretchy,” and have difficulties healing after injuries.  In the most severe cases of Ehlers-Danlos, the blood vessels are also weak, making them prone to breaking and causing internal bleeding.  Because these types of connective tissue diseases are genetic (hereditary), medical geneticists are the experts in this field.

The second type of “connective tissue disease” does not involve problems in making the building blocks of the body.  In fact, the body is able to make all of the connective tissues without a problem.  However, once these tissues are made, they are attacked by the body’s own immune system (and thus they are autoimmune diseases).  The body’s own immune cells (white blood cells) are tricked into thinking that the connective tissue is abnormal, and thus they  attacking those tissues.  In a sense, the body can build a house with high-quality materials, but the house is invaded by wild animals that can damage the structure of the house.  In Sjogren syndrome, for example, the glands that make tears and saliva are attacked.  In scleroderma, the skin and internal organs are attacked.  In lupus, many organs can be attacked, including the kidneys, skin, and lung.  To date, we have very little idea what causes these diseases.  Because these types of diseases are autoimmune and often involve inflammation, rheumatologists are the experts in these types of illnesses.

Don’t you think we should change the name that we use to refer to these two very different types of diseases?  What names do you propose?

After reading this post, what kind of disease do you think my patient had? Genetic or autoimmune?

Uncovering the mysteries of autoinflammatory diseases and other rheumatic illnesses.

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