Medical Mystery: Pain, inflammation defy easy diagnosis

B.L., a 59-year-old man, came to me in May 2014 complaining of pain in his thighs and left shoulder, as well as muscle stiffness in the mornings.

On exam, I found signs of rotator cuff tendonitis in his shoulder and torn cartilage in his left knee. I ordered lab work and an MRI of the knee and injected his left rotator cuff with a steroid, and he felt better.

Blood work revealed an elevated C-reactive protein level (CRP), indicating inflammation somewhere in the body, but it also can sometimes be a clue to something more ominous.

My nurse practitioner was concerned about polymyalgia rheumatica, or PMR. This is a systemic condition characterized by an aching pain in both shoulders and both hips that often starts suddenly and is associated with elevated markers of inflammation, such as the CRP. Standard treatment is nine months of prednisone, starting at 15 mg a day with a slow taper.

This case did not fit, however. His pain was not symmetric. His range of motion in one hip had decreased, suggesting a structural problem. And he responded well to the shoulder injection, suggesting local inflammation.

However, the shoulder pain soon recurred and we opted to give him a trial of steroids for a week - with good results. Based on his CRP and response to steroids, I decided to treat him as a PMR patient by starting him on prednisone, but I kept my eyes open for something else as I recognized his pain pattern was not classic for PMR.

By his third visit, in July, he was feeling fairly well. I listed his diagnosis as atypical PMR and began to wean him off prednisone.

At his November visit, he mentioned some hand pain, and I did note a little inflammation there, which would not be expected in PMR. Nonetheless, he was down to half of the original dosage of prednisone. I felt somewhat more comfortable with the diagnosis. But a surprise awaited me.

In January 2015, the patient began to have more pain as the prednisone was tapered further. He had a routine screening colonoscopy, and was told it showed inflammation, despite the absence of any GI symptoms such as diarrhea or abdominal pain.

This was not to last.

By February, he had developed abdominal pain, bloating, and blood in his stool and was formally diagnosed with inflammatory bowel disease (IBD).

The GI doctor started him on Mesalamine, which had an interesting side effect: His joint problems improved.

I began to suspect his joint complaints were related to his bowel disease. From a rheumatology perspective, IBD can be associated with an asymmetric inflammatory arthritis, an elevated CRP, and a variable response to steroids.

By April, he had weaned off prednisone completely. He had no further joint problems, but his gut rebelled and he had to go to the hospital. His GI doctor increased his prednisone to 40 mg with good results. Ultimately, he was started on Humira, a drug useful in IBD and also in rheumatologic conditions such as rheumatoid arthritis. When I saw him last month, he was doing well, with no joint or GI complaints.

This case offers two lessons: First, physicians must always keep their eyes open when a diagnosis is not a perfect fit. B.L.'s real problem was discovered through a routine colonoscopy, before he even had GI symptoms.

Second, keeping up with preventive care such as colonoscopies can pay unexpected dividends.

Mark Lopatin is a rheumatologist in Willow Grove and chairman of the Montgomery County Medical Society.

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