"Red eye" is one of the main reasons of urgent consultation in Primary Care and in Ophthalmologic Emergencies. In many cases, the underlying cause is a benign condition that can be managed by the Primary Care Physician. However, not every red eye is a conjunctivitis, so it is important to recognize the warning signs and symptoms associated with potentially serious conditions. Causes of red eye include diseases of the ocular surface (conjunctivitis), which are generally benign; internal eye diseases (uveitis, glaucoma, scleritis, trauma) and extraocular diseases (cavernous sinus thrombosis, orbital cellulitis), which are generally ophthalmic and systemically severe, respectively. In this expert review, we aim to provide a practical approach to the differential diagnosis of red eye in general practice, defining the criteria of severity and urgency for referral to a specialized Ophthalmology consultation.

Paediatric orbital tumours are rare, and primary orbital lymphomas are particularly uncommon, with an incidence of approximately 0.12 per 1000 000 children. Such lymphomas may present as orbital cellulitis, sinonasal or orbital masses. Due to overlapping clinical and radiological features, these cases are often misdiagnosed initially, with rhabdomyosarcoma being a common provisional diagnosis. We report a rare case of primary orbital B cell lymphoblastic lymphoma in a toddler, initially misdiagnosed as rhabdomyosarcoma, later confirmed via histopathology and immunophenotyping.

Nocardia species are infrequently associated with ocular conditions, such as keratitis, dacryocystitis, endophthalmitis, and orbital cellulitis, particularly related to ocular trauma involving vegetative matter. Their incidence in acute-onset post-operative endophthalmitis is rarely documented. We discuss a 65-year-old diabetic female patient who presented with acute-onset vision loss, with corneal perforation and panophthalmitis two weeks following cataract surgery. Evisceration had to be performed. The culture of ocular contents revealed the presence of Nocardia otitidiscaviarum, identified by MALDI-TOF MS. The case highlights the importance of microbiological diagnostics and antimicrobial susceptibility testing, coupled with early intervention in the management of acute-onset post-cataract surgery panophthalmitis.

Preseptal cellulitis is a common pediatric infection involving the eyelids and surrounding periocular tissues. It is typically benign and rarely progresses to intracranial complications, unlike orbital cellulitis. However, when secondary to rhinosinusitis, the infection may behave unpredictably and extend beyond expected anatomical boundaries. We report a rare case of migratory preseptal cellulitis in a 12-year-old boy, initially presenting with unilateral eyelid swelling, erythema, and fever. Despite prompt initiation of empirical intravenous antibiotics, the condition failed to improve and instead demonstrated an unusual migratory pattern, spreading superiorly to the forehead and crossing the midline to involve the contralateral eye. This atypical progression raised concern for deeper infection and prompted advanced imaging. Computed tomography and magnetic resonance imaging revealed maxillary sinusitis with intracranial extension, resulting in a left frontal subdural empyema. The patient underwent multiple surgical interventions, including incision and drainage of the eyelid, craniotomy for empyema evacuation, and functional endoscopic sinus surgery to address the underlying sinonasal source. Broad-spectrum intravenous antibiotics were continued, as there was no growth after 5 days of incubation. Following combined surgical and medical management, the patient made a full recovery within 20 days, with complete resolution of neurological and ocular symptoms. This favorable outcome underscores the importance of early recognition and aggressive treatment of intracranial complications arising from seemingly localized infections. This case highlights that intracranial extension can occur even in preseptal cellulitis, particularly when symptoms worsen or fail to respond to standard therapy. Migratory eyelid swelling should heighten clinical suspicion for atypical or progressive disease. Prompt imaging, identification of the primary infectious source, and timely multidisciplinary intervention are essential to prevent life-threatening complications.

Extranodal natural killer (NK)/T-cell lymphoma is a rare malignant tumor, more prevalent in Asia and Latin America, and associated with Epstein-Barr virus infection. Its diagnosis is challenging due to its clinical presentation, which may mimic chronic sinusitis, dacryocystitis, or granulomatous diseases. This lymphoma follows a rapid and aggressive course, with a poor prognosis. We report the case of a 71-year-old man presenting with nasal obstruction, clear rhinorrhea, and facial heaviness. Initially, acute dacryocystitis and periorbital cellulitis were suspected and treated with antibiotics; however, the patient showed a poor response. After multiple consultations and unsuccessful treatments, a biopsy confirmed the diagnosis of extranodal NK/T-cell lymphoma of the nasal type. Histopathological and immunohistochemical analysis revealed an infiltrate of atypical lymphocytes positive for cluster of differentiation 2 (CD2), cluster of differentiation 56 (CD56), T-cell intracellular antigen-1 (TIA-1), and Epstein-Barr virus-encoded RNA (EBER), with prominent tissue necrosis. This case highlights the diagnostic challenges and aggressive clinical course of sinonasal NK/T-cell lymphoma. Its initial presentation can mimic common inflammatory conditions, requiring a high index of suspicion. Standard treatment includes combined chemotherapy and radiotherapy, yet the prognosis remains poor. This report aims to raise awareness of this entity and emphasize the importance of considering it in atypical or treatment-refractory cases of orbital cellulitis, bacterial sinusitis, and other inflammatory conditions.