Mycoplasma Pneumoniae

Case studies (adult and pediatric) associating mycoplasma pneumoniae infection with both dermatomyositis and polymyositis onset and progression, as well as the outcomes of various treatment approaches.

A Pediatric Case of Polymyositis Associated with Mycoplasma pneumoniae Infection. Scandinavian Journal of Rheumatology. Volume 26, 1997 – Issue 6

The case of a 10-year-old female is described, who developed polymyositis that was associated with mycoplasma pneumoniae infection. The child was diagnosed, based upon mild muscle weakness, elevated muscle enzymes and muscle biopsy. Neither oral prednisone nor IV methylprednisolone pulse therapy was effective and she was put on the immune-suppressant medications, cyclophosphamide and methotrexate. Study authors report this to be the first case of steroid-resistant polymyositis, associated with m. pneumoniae infection.

A Case of a 14-year-old Girl Who Developed Dermatomyositis Associated with Mycoplasma pneumonia Infection. Soonchunhyang Med Sci. December 2015. 21:130-33.

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The case of a 14-year-old girl is presented who had a two-week history of fever, fatigue and myalgia. Laboratory investigations confirmed infection with mycoplasma pneumoniae and juvenile dermatomyositis. The child was treated with the antibiotic, clarithromycin 500mg daily, and within one week, mycoplasma IgM and IgG antibodies had significantly decreased, but myalgia and muscles enzymes had increased (Jarisch-Herxheimer?) and a pruritic rash evolved. By the 9th day, shortness of breath was experienced and X-rays of the lungs indicated ground glass opacity and pleural effusions. The child was then treated with IV immunoglobulin and high dose prednisone that was then tapered, whereupon methotrexate was added. Due to hair loss methotrexate was switched to mycophenolate mofetil, and she tapered the prednisolone to 5 mg every other day and maintained this protocol, without recurrence. In a discussion of this case report, study authors examine the infectious triggers of myositis diseases, indicating that respiratory infections seemed to be a common occurrence in the 3 months prior to disease onset. The authors also state that extra-pulmonary manifestations including pericarditis, arthritis, and encephalitis can be caused by Mycoplasma pneumoniae by mechanisms described in their concluding remarks. A few previous cases of Mycoplasma pneumoniae-induced polymyositis have been recorded in the literature, but these authors claim that dermatomyositis may also manifest as a result of this infection.

Myositis related to mycoplasma infection. Postgrad Med J 1993;69:959–60.

The case of a 21-year-old male, suffering from headache, fever, shortness of breath, dry cough, and gastrointestinal symptoms, including cramping, diarrhea, nausea and vomiting, but denying arthralgia or myalgia, is described who, upon clinical work-up, was found to have hypoxia with respiratory alkalosis, elevated liver and muscle enzymes (creatinine kinase of >16,000 IU/l) and also mildly-elevated white blood cells. X-ray of the lungs showed a diffuse interstitial pattern. Upon infection testing, elevated IgM and IgG mycoplasma titers were found and he was treated with IV fluids, alkalinization and erythromycin, whereupon he made a full recovery. The author of this Letter states that previous reports of antibodies to smooth muscles and mycoplasma pneumoniae have been documented and that this case should be added to the list of prior reports so that awareness of the association of this infection with myositis is increased in diagnostic work-ups of similar cases.

Acute polymyositis in an adult associated with Mycoplasma pneumoniae infection. Postgrad Med J 1990;66:47–8.

Case report of an otherwise healthy adult who contracted mycoplasma pneumoniae and developed acute polymyositis as a complication of this infection.

More on polymyositis associated with Mycoplasma pneumoniae infection. Scand J Rheumatol 1999;28:125.

Case report of a healthy 27-year old woman, presenting with a two-week history of progressive muscle weakness and diffuse muscle pain that was preceded by a sore throat and persistent dry cough. Lab studies revealed moderately elevated ESR and highly elevated LDH, liver and muscle enzymes and positive autoimmune panel, including ANA, anti-Jo-1 antibody, anti-DNA antibody, anti-Sm antibody and anti-RNP antibody. Extensive infection testing proved mycoplasma pneumoniae infection based upon positive muscle biopsy and serologic elevations in both IgM and IgG detected by immunofluorescence testing. The treatment described for the acute infection was hospital bedrest for 11 days, at which time the patient was discharged and improved.  One month later the patient had made a complete recovery and had no relapses were reported at 17 months. The author concludes that this patient exhibited all the clinical and pathological features of polymyositis, induced by upper respiratory tract infection of mycoplasma pneumoniae. Also, the case was unique by way of spontaneous remission that may be the result of an interplay of genetics and autoimmune factors that may produce sub-sets of mycoplasma pneumoniae-induced polymyositis.

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