Fever and Arthritis 3
Nina a previously healthy 8 year-old female and from a rural area in Brazil, was referred to Paediatric Rheumatology with a 2 week history of prolonged fever, weight loss and limb pain. She had an abnormal musculoskeletal exam with limited movements due to pain and could not raise her arms above the shoulders on pGALS assessment. She also had axillary lymph nodes but no hepatosplenomegaly.
Investigations showed high ESR and CRP, normal muscle enzymes. Blood film showed no evidence of malignancy but high platelets and eosinophils. Bone marrow biopsy was unremarkable except for bone marrow reactive inflammation with eosinophils infiltration. Chest radiograph showed asymptomatic subtle middle lobe lung infiltrate with symmetrical osteolytic lesions in both clavicles and humerus metaphysis.
Her pain was not controlled with pain killers or NSAIDs and a bone biopsy indicated a specific granulomatous osteomyelitis with positive staining for Paracoccidioides brasilienses. She was treated with cycles of co-trimoxazole and lipid formulated B-amphotericin followed by itraconazole. During her follow up she also presented with symmetrical arthritis involving wrists, elbows and ankles and a new osteomyelitis focus was identified in the calcaneum suggesting a treatment resistant osteomyelitis.
Diagnosis: Osteomyelitis due to South American blastomycosis
- Bone lesions with lytic appearance, prolonged fever, and bone inflammatory infiltrate with eosinophilia and positive fungal staining were clues for her diagnosis, but the musculoskeletal symptoms were her presenting features. She had no evidence of being immunosuppressed.
- South American blastomycosis also known as Paracoccidioidomycosis results from spore inhalation following exposure to contaminated soil in endemic area, and represents only 3% to 10% of all reported cases. Most children have pneumonia; skeletal involvement is more common than cutaneous manifestations. It is a well-known but infrequently seen complication of Paracoccidioides sp infection. Septic arthritis generally occurs secondary to osteomyelitis of adjacent bones. Diagnosis is usually performed by typical budding yeast forms on histology.
- Although rare, this diagnosis should be considered in the differential diagnosis of bone pain in children and adolescents living in endemic areas (Latin America) or having travelled to an endemic area. Both immunocompetent and immunocompromised persons can be infected, but more severe disease occurs in the immunocompromised.
- Blastomycosis is endemic in Latin America. It is described, albeit rarely, in North America and Europe and in these cases, prior residence in Latin America was documented.
Further information is available - Centre for Disease Control and Prevention