Reactions Weekly | 2019
Methotrexate/nonsteroidal anti-inflammatory drugs/steroids
Abstract
Amoebic encephalitis due to Balamuthia mandrillaris species: case report A 71-year-old man developed fatal amoebic encephalitis due to Balamuthia mandrillaris during treatment with methotrexate, unspecified steroids and unspecified NSAIDs for rheumatic arthritis [route and dosage not stated]. The man presented to the hospital in South-Korea with partial spasm from the left thigh to the left upper limb for a day without any infectious symptoms. He had a history of rheumatic arthritis for 30 years and had been receiving immunosuppressive therapy with methotrexate, unspecified NSAIDs and steroids. Initial MRI of the brain showed numerous ring-enhancing nodules in both cerebral hemispheres sized up to 3.7 × 3.2 × 1.8cm, based on which a brain metastasis of an unknown aetiology was suspected. Blood work-up showed normal WBC count and increased CRP level. The CSF analysis showed elevated protein level and normal glucose level. A week later, he complained of stuporous mentality and fever. Hence, a second brain MRI was performed, which showed number of nodules that were larger as compared with the first MRI. Thereafter, he was admitted and an open biopsy of the brain was performed. During the procedure, the frozen sections with squash preparation revealed an acute inflammation along with haemorrhagic necrosis; however, no final diagnosis could be made. After the procedure, the permanent sections revealed diffuse or perivascular infiltration of amoebic trophozoites in the setting of necrosis and haemorrhage. Some scattered cysts were also observed. Based on all these findings and symptoms, a final diagnosis of amoebic encephalitis due to Balamuthia mandrillaris was made. The man was treated with pentamidine and paromomycin. On day 10 of the admission, he died due to amoebic encephalitis. Author comment: Unlike the other amoeba species, Balamuthia mandrillaris affects not only immunocompromised but also immunocompetent people, especially the young and the elderly.