Dr. Monach, can you walk us through your approach to this patient? Are we seeing manifestations of fibromyalgia? What diagnoses concerns you and how would you proceed?
►Dr. Monach. The history and exam are most helpful in raising or reducing suspicion for an underlying inflammatory disease. Areas of tenderness described in her case are typical of fibromyalgia, although it can be difficult to interpret symptoms in the hip girdle and shoulder girdle because objective findings are often absent on exam in patients with inflammatory arthritis or bursitis. Similarly, tenderness at sites of tendon insertion (enthuses) without objective abnormalities is common in different forms of spondyloarthritis, so tenderness at the elbow, knee, lateral hip, and low back can be difficult to interpret. What this patient is lacking is prominent subjective or objective findings in the joints most commonly affected in rheumatoid arthritis and lupus: wrists, hands, ankles, and feet.
►Dr. Swamy. Initial laboratory data include an erythrocyte sedimentation rate of 79 with a normal C-reactive protein. A tentative diagnosis of polymyalgia rheumatic is made with consideration of a trial treatment of prednisone.
Dr. Monach, this patient has an indolent infection and is about to be given glucocorticoids. Could you describe the situations in which you feel that glucocorticoids cause a relative immunosuppression?
►Dr. Monach. Glucocorticoids are considered safe in a patient whose infection is not intrinsically dangerous or who has started appropriate antibiotics for that infection. Although all toxicities of glucocorticoids are dose dependent, the long-standing assertion that doses below 10 mg to 15 mg do not increase risk of infection is contradicted by data published in the past 10 to 15 years, with the caveat that these patients were on long-term treatment.
►Dr. Swamy. The patient was started on prednisone 15 mg per day for 15 days. She returned to the clinic after 1 week of prednisone troutment and noted “significant improvement in fatigue, morning stiffness of shoulders, thighs, leg, back is better, leg cramps resolved, shooting pain in many joints resolved.” Further laboratory results were notable for a negative rheumatoid factor, negative antinuclear antibody, and a cyclic citrullinated peptide of 60. A presumptive diagnosis of rheumatoid arthritis (RA) was made and plaquenil 200 mg twice daily was started.
Dr. Monach, can you explain why RA comes up now on serology but was not considered initially? Why does this presentation fit RA, and was her response to treatment typical? How does this fit in with her previous diagnosis of fibromyalgia? Was that just an atypical, indolent presentation of RA?
►Dr. Monach. Though her presentation is atypical for RA, in elderly patients, RA can present with symptoms resembling polymyalgia rheumatica. The question is whether she had RA all along (in which case “elderly onset” would not apply) or had fibromyalgia and developed RA more recently. The response to empiric glucocorticoid therapy is helpful, since fibromyalgia should not improve with prednisone even in a patient with RA unless treatment of RA would allow better sleep and ability to exercise. Rheumatoid arthritis typically responds very well to prednisone in the 5-mg to 15-mg range.
►Dr. Swamy. Given the new diagnosis of an inflammatory arthritis requiring immunosuppression, bronchoscopy with BAL is performed to evaluate for the presence of MAC. These cultures were positive for MAC.