Home > Case of the Week

Title : 19 year-old male w/Fever which sustained for a month
Date : January 27, 2012
Contributed by

Contributed by Eun-Jeong Joo, M.D, Samsung Medical Center, Korea

Patient History
Age/Sex 19 year-old male
Chief complaint Fever which sustained for a month
Present illness

The patient visited Samsung Medical center complaining of fever and calf pain. Fever developed a month ago and followed by cough and sputum. Despite antibiotic therapy in local clinic, fever waxed and waned. Within a week prior to visiting, he had suddenly felt leg pain on both calves. For the further evaluation of FUO, he was requested to outpatient clinic of division of infectious diseases in Samsung Medical Center.

Past medical history

He had been diagnosed to have HS purpura and recovered without complication 11 year ago.

He has been treated as gonorrhea 6 months ago. 

*Social history

He has multiple sex partners except a girlfriend.

He enjoyed eating raw meat and fish. Two months ago, he ate meat of wild boar in some of which was not well cooked. 

Physical examination

Body temperature was 38.3°C

Tenderness was detected on both calves

Initial laboratory findings

WBC 12,000/uL(eosinophil 2.9%)

CRP 2.35mg/dL

procalcitonin 0.69

Muscle enzymes were within the normal limit

Enzyme immunoassay for Mycoplasma pneumonia, IgG/IgM (+/+)

Anti HIV Ab (-)

Urinary analysis was clear

RPR non-reactive, TPLA non-reactive

FANA negative, ANCA negative

Radiologic findings


Normal heart function, initially



Radiologic findings

Chest and abdomen CT showed non-specific findings

Multifocal patch high signal intensity lesions were observed in both lower leg in MR imaging  

Hospital course

Under the impression of extrapulmonary mycoplasma infection, azithromycin (500mg q 24hr) was prescribed to him for 7 days. Despite initial improvement of fever and calf pain, high fever was saddened observed after 7 days of treatment and chest pain developed. Echocardiography revealed the typical features of acute pericarditis. Tissue specimens which had been biopsied from calves area showed the infiltration of lymphocyte and nuetrophils, but there was no evidence of parasite or eosionphilic infiltration.

Question - ID Case of the Week ( January 27, 2012 )
What is your presumptive diagnosis for this patient?
Correct Answer

Extrapulmonary mycoplasma infection presenting with myositis and pericarditis




Serology is an important tool for the diagnosis of M. pneumoniae infection. Before the availability of more advanced serologic techniques, detection of cold agglutinins was considered a valuable tool for M. pneumoniae diagnosis. However, cold agglutinins are not very reliable indicators for M. pneumoniae infection, as they are elevated in only 50-60% of patients. In order to achieve a rapid diagnosis, separate detection of IgM antibodies is helpful. IgM antibodies appear during the first week of the illness and reach peak titers during the third week. They decline towards lower levels within a few months. A major disadvantage of IgM-based diagnosis is that these antibodies are not constantly produced in adults, most likely as a result of multiple previous infection. Therefore, a negative IgM result does not rule out acute M. pneumoniae infection in the elderly. In contrast, measurement of IgM has been shown to be useful in pediatric patients.


In this case patient, extrapulmonary mycoplasma infection was diagnosed because IgM antibodies for M. pneumoniae were positive, and then this positive result of IgM has shown to be very reliable as a diagnostic tool in young aged group. M. pneumoniae infection usually manifested extrapulmonary symptoms in 25-50% of patients. Maculopapular rash was observed in 25% of cases and cases presenting with myositis are extremely rare with just a few case reports. Cardiac involvement including myopericarditis accounts for less than one percent.


This patient was initially treated with azithromycin for 7 days, but fever redeveloped. At this point, we suspected macrolide resistance of M. pneumoniae and changed the regimen to levofloxacin. Colchicine and NSAIDs were also co-administered to treat acute pericarditis. Chest pain and fever was improved after 7 days of treatment with levofloxacin and antipyretics. The patient was discharged without any complication.     


Macrolide resistant M. pneumoniae isolates possessing a nucleotide mutation in 23S rRNA first were isolated from pediatric patients with CAP, as reported by Okazaki and colleagues in 2001. Together with growing use of macrolide in Japan, resistant strains increased rapidly year by year. Subsequently, a high isolation rate (92%) were reported in China


In South Korea, detection of genetic mutations associated with macrolide resistance was performed in nasopharyngeal aspirates from 62 children diagnosed as M. pneumoniae between 2000 and 2003, but the A2064G mutation was observed in 1 specimen. In 2011, the genetic mutation related to macrolide resistance was confirmed in several pediatric cases diagnosed as M. pneumoniae including one patient in SMC. Although the increasing prevalence of macrolide resistance was not reported yet in recent Korea studies, the rapid dissemination of resistance in Japan and China might affect Korean population in a moment.   




Dexboeck et al. Clin Microbiol Infect 2003;9:263-73

Morozumi et al. J Infect Chemother 2010;16:78-86

Oh et al. Korean J Pediatr 2010;53:178-83


޴ٷΰ ΰ