Bilateral Atopic Cataracts in a Child with Eosinophilic Esophagitis: An Association to Look Out For

INTRODUCTION Eosinophilic esophagitis is a poorly understood clinicopathologic entity that is quite different from the relatively better known forms of eosinophilic enteropathies. It is characterized by the presence of 20 or more eosinophils per high-power field in esophageal mucosal biopsy specimens. It may present with mucoid vomiting and dysphagia, often of intermittent nature, which may lead to the misdiagnosis of this condition as simple gastroesophageal reflux (1). Apart from dietary exclusion regimens, primary eosinophilic esophagitis has been successfully treated with not only systemic but also inhaled corticosteroids, particularly fluticasone propionate (2,3). These lend support to the hypothesis that there is an allergic component in its etiopathogenesis. We report the development of bilateral atopic cataracts necessitating surgical extraction followed by intraocular lens implantation in a child with eosinophilic esophagitis. CASE REPORT A 15-month-old boy was referred with poor weight gain and persistent vomiting since 8 months of age. There had been no improvement with thickened feedings, antacids or ranitidine. The patient's mother gave a history of hay fever, and his elder sibling had had eczema as an infant. There was no family history of cataracts and the antenatal period was uneventful. Remarkable investigations were an eosinophil count of 1240 cells/cubic millimeter (normal range, up to 800/cubic millimeter) and an elevated immunoglobulin E of 101 IU/L (normal range, 0 to 15 IU/L). His complete blood count was otherwise normal, as were hepatic and renal function tests, sweat test and celiac disease screen. Upper gastrointestinal barium contrast study was normal. Upper endoscopy revealed a macroscopically edematous and furrowed oesophageal mucosa. Histology revealed marked basal cell hyperplasia, elongation of the papillae with large numbers of intraepithelial eosinophils, between 14-27 (average, 22) per high-powered field, of which numerous appeared to be degranulated (Fig. 1). These findings were present in biopsies taken both from mid- and lower esophagus. The stomach and duodenum were macroscopically and microscopically normal, as was the colon on a subsequent occasion.FIG. 1: Photomicrograph of a hematoxylin-and-eosin stained esophageal mucosal biopsy taken from the mid-esophagus representing one high-powered field. The presence of more than 20 eosinophils is diagnostic of an eosinophilic esophagitis.Use of an elemental feed (Neocate, SHS International) was associated with an amelioration of symptoms that returned on reintroduction of normal feedings. He was treated with two short courses of 20 mg of prednisolone once a day for 2 weeks, followed by a 3 week taper. At 3.5 years of age his parents became concerned that he insisted on standing close to the television when viewing. Their concerns were heightened as the patient's elder sibling had earlier undergone treatment of amblyopia in one eye and his maternal grandfather had monocular blindness secondary to longstanding undiagnosed amblyopia in childhood. Ophthalmologic assessment employing routine refraction followed by slit-lamp examination revealed bilaterally decreased visual acuity (right eye, 3/7.5; left eye, 3/24) secondary to atopic cataracts in both eyes. The optic discs were normal. At 4.5 years he underwent surgical extraction of the left cataract followed by intraocular lens implantation. The immediate postoperative period was complicated by the development of a slow-onset anaphylactoid reaction in the form of pallor, floppiness, excessive sweating and bronchospasm possibly related to the use of codeine analgesia. He briefly required intensive therapy with fluid resuscitation, corticosteroids and antihistamines and recovered in several days. His right eye lens did not show any further progression and the opacities were confined to the periphery. Presently there are no immediate plans for surgery on the right eye. DISCUSSION Eosinophilic esophagitis is an inflammatory lesion characterized by a dense and diffuse infiltration by eosinophilic granulocytes of the esophageal mucosa and submucosa, without involvement of other areas of the gastrointestinal tract in the absence of gastroesophageal reflux or parasitic infestations (4). It appears to have an allergic component and exposure to air allergens and food allergens may have an aetiological role (5,6). Eosinophilic degranulation followed by the release of inflammatory mediators such as major basic protein, eosinophil cationic protein, peroxidase and other free oxygen radicals are all thought to be involved in the pathogenesis of this disease (7). Atopic cataracts are a recognized associated condition in adults and children with atopic eczema, although there are no reliable prevalence data. They are especially found in those with significant facial involvement and/or wearers of contact lenses (8). Similar "allergic" cataracts have also been seen with parasitic infestations such as toxocariasis in which they are thought to be caused by the eosinophilic response to the Toxocarae larvae. The eosinophil is thought to play a pivotal part in the development of atopic cataracts. Yokoi et al. demonstrated epithelial major basic protein deposition in the anterior lens capsule lens of adult patients with atopic cataract in association with eczema (9). Moreover, major basic protein was also detected in the aqueous fluid of these patients. There are two mechanisms proposed to explain the development of atopic cataracts. First, because the lens is epidermal in origin, atopic processes might affect it in the same way as other epidermal tissues such as skin, mucosa and smooth muscle. Alternatively the lens might be indiscriminately affected by cationic proteins released from activated eosinophils, especially major basic protein, causing cell damage and cataract formation. Two morphologic types of atopic cataract have been described. Most commonly there is an anterior plaque or shield-like opacity, which lies subcapsularly and in the pupillary zone. These result in anterior subcapsular cataracts that are also seen after uveitis, trauma, irradiation and rare conditions such as Alport's syndrome (10). The "complicated" type is less common. Changes start at the posterior pole in the immediate subcapsular region. This can result in cataractous changes in the posterior subcapsular region that are often indistinguishable from those brought about by corticosteroid therapy (11). Our patient had opacities in the posterior capsule of the latter type. Although on occasion even short-term steroids can cause posterior cataracts, in the majority of cases these are related to large doses. We feel it is unlikely that the cataracts reported here are related to the short course of low dose oral prednisolone our patient received. Moreover there were no antenatal or extraneous factors that could have predisposed to the development of congenital or early-onset cataracts. In view of the rarity of both these conditions and the biologic plausibility that eosinophils link the two problems, we postulate that there may be an association between eosinophilic esophagitis and the development of cataracts that is independent of the use of steroids. The patient had no other risk factors for the development of "atopic" cataracts. To the best of our knowledge, this is the first reported case of eosinophilic esophagitis complicated by the development of cataracts. A MEDLINE search using the search terms "Oesophagitis"/"Esophagitis" AND "Cataract"/ AND "Eosinophils" did not find any reports of this association. We feel that it is prudent to be aware of this possible association and to routinely check for cataracts in this condition and to have a low threshold of suspicion if there are any concerns over visual acuity. Our patient developed clinical symptoms of eosinophilic esophagitis in infancy, whereas in the series reported by Orenstein et al. the median ages at onset of symptoms and diagnosis were 4 years and 7 years, respectively (12). In addition our patient has a persistent eosinophilia and elevated immunoglobulin E, which are not a consistent association of eosinophilic esophagitis. It is possible that these features represent specific risk factors for the development of this complication. In conclusion, we report a previously unrecognized and potentially serious association of eosinophilic esophagitis and suggest regular ophthalmic assessments as part of the follow-up of patients with this challenging problem.