292. Central retinal artery occlusion as debut of pediatric ANCA-associated vasculitis: a case report

Presentation of case: An eleven-year-old female patient previously healthy presented to us with a 3-month history that begins with bilateral conjunctival injection and headache. After 2 months, other symptoms were associated such as arthralgia, myalgia, and feverish sensation. Finally, in the week before hospital admission, skin lesions with purpuric characteristics were added in the lower limbs, and visual acuity of the right side decreased acutely. The physical examination revealed localized dermatosis at the level of the lower limbs, with brownish crusty lesions and other purpuric lesions, some with a bullous center. In the right eye, total amaurosis was observed, areflectic pupil, photo-motor reflex absent. The ophthalmological examination revealed retinal hemorrhage in the right eye, which made it impossible to visualize the posterior pole, which is why angiofluorescein was performed, which reported absence of perfusion of the central artery of the right retina and ocular ultrasound that reported serous detachment of the right retina. Diagnostic testing: Laboratory tests reveal involvement of multiple systems, increased inflammatory markers (CRP: > 118.6 mg/dl, fibrinogen= 634 mg/dl), C3, C4 in range, ANA and ANTI DNA negative, microhematuria (10-12/field), proteinuria (30 mg/dl), ANCA myeloperoxidase (MPO) positive (>300). Echocardiogram and abdominal ultrasound were normal. An infectious examination was negative for tuberculosis, HIV, CMV, Toxoplasmosis, blood culture. The skin biopsy reported residual changes of leukocytoclastic vasculitis, with thrombosis. In papillary and residual dermis, dilated capillaries were seen, some congestive with thrombi inside, surrounded by lymphocytes, with few neutrophils, and nuclear dust. Renal biopsy was indicated, where 31 glomeruli were observed, some totally sclerosed, others with segmental sclerosis, with fibrinoid necrosis, fibrin exudate and fragments of neutrophil nuclei, corresponding to a focal segmental necrotizing glomerulonephritis, throwing the diagnosis of microscopic polyangiitis.

Discussion and Management: The patient presented with a systemic disease that started with non-specific symptoms. Myalgias, arthralgias, mild fever and finally there were multiple palpable purpuric lesions on the lower limbs, leading to suspicion of inflammatory small vessel disease. Henoch-Schoenlein purpura is the most common systemic small vessel vasculitis in children; however, the sudden decrease in vision in her right eye required further diagnostic testing. The elevations of inflammatory markers but above all hemogram with presence of toxic granulations (15%) lead us to initiate antibiotic therapy. Despite this treatment we observed extension of skin lesions, persistence of inflammatory markers elevated, urinalysis revealed hematuria and proteinuria, so small vessel vasculitis was suggested as a diagnosis, and noting the central retinal artery occlusion (CRAO) that can affect the quality of life of the patient, we started immediate immunosuppressive therapy with methylprednisolone, at 1g/day for three days followed by oral prednisolone. After having renal biopsy results confirming small vessel vasculitis and positive ANCA-MPO, an ANCA-associated vasculitis (AAV) was confirmed. She also received cyclophosphamide (3 doses currently). Despite the start of corticosteroid therapy, and treatment with cyclophosphamide, there was no improvement in right visual acuity.

Conclusions: AAV is extremely rare in the paediatric population, making diagnosis a real challenge. Total CRAO, due to its rarity, requires a high diagnostic suspicion based on clinical, physical examination and laboratory analysis. Immediate administration of corticosteroids is sometimes necessary, especially when severe complications occur that can negatively impact quality of life such as CRAO.

Disclosures: None

Figure: Clinical manifestations at cutaneous and ocular level