Methods: The patient was a 56-year old Caucasian woman suffering from rheumatoid arthritis since 1995. She was subsequently diagnosed with Sjoegren’s syndrome and autoimmune thyroiditis. In 2009, the patient had a skin rash which disappeared after corticosteroid treatment. In January 2012 a routine chest X-ray detected a pleural effusion, that was treated by various cycles of antibiotics and corticosteroids without improvement. The patient was then referred to us because of a concomitant eosinophilia. She also had difficulty in breathing, and allergy was suspected as a possible cause. The patient underwent allergy tests, parasitological evaluation and a routine blood examination, including IgG antibodies to T. canis.
Results: Allergy tests were negative, while IgG antibodies to T. canis were positive by both ELISA and Western Blotting. An anti-elminthic treatment was prescribed using mebendazole (one 100 mg tablet b.i.d. for three days), repeated in subsequent cycles with a 1-month time interval. After the first cycle, a chest X-ray showed that the pleural effusion had improved. Complete recovery was shown after 4 months by X-ray and ecography, being associated to a negative serology result for T. canis and to resolution of eosinophilia.
Conclusions: T. canis infection should be taken into account in cases of pleural effusion resistant to conventional treatment. The in vitro detection of T. canis-specific IgG antibodies leads to appropriate, effective anti-elminthic treatment.