Introduction

Acute-onset strabismus and diplopia in children are clinically alarming symptoms with a broad differential diagnosis, ranging from benign refractive errors to serious intracranial pathologies.​​ Prompt and accurate evaluation is essential to ensure proper treatment and prevent visual and neurological complications.

Material and methods

We present a retrospective case series of five paediatric patients referred to our centre with sudden-onset strabismus. Clinical findings, diagnostic workup, management, and outcomes were analysed.

Results

The underlying aetiologies were heterogeneous. Two children were diagnosed with acquired esotropia – one partially accommodative, necessitating optical correction, and non-refractive in the other. Surgical treatment was performed in both patients. One patient presenting with vertical strabismus, nystagmus, and headache was later diagnosed with neuroborreliosis and concurrent human herpesvirus (HHV)-6 and HHV-7 infections, with complete resolution after targeted antimicrobial therapy. Another patient developed acute esotropia secondary to sinusitis with orbital involvement, resolving after endoscopic sinus surgery and systemic treatment. The final patient, diagnosed with hydrocephalus from a pineal gland tumour, presented with acute-onset exotropia, limited eye movement, headaches, and vomiting.

Conclusions

Sudden-onset strabismus in children should be regarded as a potentially urgent clinical presentation. A detailed history and comprehensive physical examination are essential to identify red flags, including cranial nerve dysfunction, nystagmus, and signs of increased intracranial pressure, which warrant urgent neuroimaging and multidisciplinary management. If systemic symptoms are absent, refractive causes should be considered initially, with cycloplegic refraction as a first-line diagnostic step. This individualised diagnostic approach facilitates early, accurate diagnosis, reduces unnecessary investigations, and optimises therapeutic outcomes.