We report a 14-year-old male, born in Ecuator, diagnosed of severe idiopathic aplastic anemia who underwent an allogeneic bone marrow transplantation from his HLA-identical sibling donor. The early phase of transplantation was uneventful and the patient achieved full-donor chimerism on day +11 postransplant. He was discharged home on day +13 with prophylactic cyclosporine, acyclovir, fluconazole and trimethoprim/sulfamethoxazole with a hesitant treatment adherence.
On day +70 he presented with a sudden onset of diminished vision of the right eye without other symptoms. Physical examination was normal except his fundus eye that showed a white mass in the posterior pole of the right eye extending toward the macula suggestive of granuloma (see Fig. 1). A cranial CT and laboratory test were normal. He did not have peripheral eosinophilia. Stool parasites were negative. The differential diagnosis was made with toxoplasmosis, toxocariosis, neurocysticercosis, retinoblastoma and virus infections that were discarded. The serum enzyme-linked immunosorbent assay test (ELISA) IgM and IgG were positive for Toxocara canis (0.67, normal up to 0.25) and he was diagnosed of ocular toxocariasis. Despite the lack of an optimal treatment for OT, some patients can be treated successfully with anthelmintic drugs and systemic or periocular corticosteroids. Steroids can limit the inflammation or fibrosis in a patient who had a sudden onset of diminished vision. This case was considered a medical emergency because the patient had severe symptoms. Thus, he received treatment with topic steroids and oral Albendazole for 5 days with a good outcome. After the treatment of toxocariasis the fundus eye examination showed a decrease in the size of the granuloma with disappearance of macular involvement.
Toxocariasis is a zoonotic disease caused by the infestation of humans by second stage larvae of the dog nematode T. canis or the cat nematode Toxocara cati.1 Prevalence estimates for the United States ranged from 8% to 15%, depending on the age, the region and socioeconomic status.2 Ocular toxocariasis mainly affects younger children and constitutes 1–2% of uveitis in children. Since many infections were asymptomatic and thus can be misdiagnosed, the global burden of toxocariasis is likely to have been underestimated. The highest number of ocular toxoplasmosis cases has been reported in Japan and Korea, France, Brazil and the USA. Inflammation is typically unilateral. This parasite can cause uveitis, posterior and peripheral retinochoroiditis, endophthalmitis, papillitis,1,3 and other ocular lesions that often lead to loss of vision in the affected eye. Because of its specificity, serum enzyme-linked immunosorbent assay (ELISA) is helpful in identifying patients with ocular toxocariasis. The test is highly sensitive (78%) and specific (92%), but the sensitivity and specificity vary according to the cut-off titter chosen to define a positive test.4 Fundus photography, fluorescein angiography, ophthalmic ultrasound and OCT can assist in the detection of eye granulomas and in the differentiation of OT from similar ocular conditions.5,6
Prevention of the infection is based on measures such as appropriate health care for dogs and cats, including regular antihelmintic treatments, prevention of contamination of the environment with feces, and responsible pet ownership. Furthermore, precautions based on hygiene are required, and education is important for prevention.7
Our patient had very bad social conditions with a poor level of hygiene. He also had a dog at home, so with this clinical history and the typical lesions observed in his fundus eye, the diagnosis of ocular toxocariasis was made. He had a good outcome with the treatment with a partial recovery of vision and a decrease in the size of the granuloma with disappearance of macular involvement. In ocular toxocariasis therapy should be guided according to visual acuity, severity of inflammation or irreversible ocular damage.1,8
In conclusion, in an immunocompromised patient who suffers an infection we do not have to consider only typical infections secondary to the poor recovery of the immune system such as toxoplasma or cytomegalovirus, but also imported infections. A good clinical history, keeping in mind the origin of the patient and the socioeconomic status can help us to find the right diagnosis.
Funding sourceThere are no study sponsors.
Conflict of interestThe authors declare no conflict of interests.
