Acute acquired toxoplasmosis causing neuroptico-meningoencephalitis in an immunocompetent boy

Atypical presentations of ocular toxoplasmosis

The diagnosis of ocular toxoplasmosis is based most often on the presence of characteristic clinical findings, which include focal retinochoroiditis, an adjacent or nearby retinochoroidal scar, and moderate to severe vitreous inflammation. However, a variety of less common, "atypical" presentations may be unfamiliar to clinicians, delaying both diagnosis and treatment. Patients who are immunocompromised or elderly may, for example, present with large, multiple and/or bilateral lesions. Other unusual manifestations include punctate outer retinal toxoplasmosis, retinal vasculitis, retinal vascular occlusions, rhegmatogenous and serous retinal detachments, a unilateral pigmentary retinopathy mimicking retinitis pigmentosa, neuroretinitis and other forms of optic neuropathy, and scleritis. Although in the past most cases of ocular toxoplasmosis were considered to result from reactivation of a congenital infection, it is now believed that postnatally acquired infection accounts for many cases of this disease. With appropriate use of antiparasitic therapy, the visual prognosis for patients with both typical and atypical forms of ocular toxoplasmosis may be good.

Toxoplasmosis neuroretinitis

BACKGROUND

Neuroretinitis is a distinct clinical entity consisting of moderate to severe visual loss, optic nerve head edema, macular exudate in a stellate pattern, and variable vitreous inflammation. Although the etiology is usually postviral or idiopathic, an acute infectious cause occasionally is demonstrated.

METHODS

Five juvenile or young adult patients with neuroretinitis are presented with serologic evidence of Toxoplasma gondii infection. Four of the five patients were treated with systemic antibiotics and corticosteroids; one patient was not treated.

RESULTS

With a mean follow-up period of 50 months, visual acuity returned to 20/25 or better in four patients, with one patient regaining visual acuity of 20/60. Two patients had one or more recurrent episodes of neuroretinitis, distinguishing toxoplasmosis from idiopathic neuroretinitis, which is usually a monophasic illness.

CONCLUSION

Toxoplasmosis infection is a rare, but potentially treatable, form of neuroretinitis and should be included in the differential diagnosis of "Leber's idiopathic stellate retinopathy."