What is the most likely diagnosis and recommended work‑up for a 4‑year‑old boy with bilateral gray‑blue discoloration of the outer one‑third of the sclera present since birth?

Bilateral Gray-Blue Scleral Discoloration in a 4-Year-Old: Diagnosis and Work-Up

Most Likely Diagnosis

This presentation is most consistent with oculodermal melanocytosis (nevus of Ota) or scleral melanocytosis, benign congenital pigmentary conditions affecting the sclera and periocular tissues that require ophthalmologic evaluation to rule out associated ocular complications, particularly glaucoma. 1

The bilateral gray-blue discoloration of the outer third of the sclera present since birth in an otherwise healthy 4-year-old represents a congenital pigmentary anomaly rather than a systemic disorder. While the provided evidence focuses heavily on methemoglobinemia, that condition presents with diffuse slate-gray or lavender discoloration of mucous membranes (lips, buccal mucosa) and skin—not isolated scleral changes. 1 Methemoglobinemia causes generalized cyanosis that does not improve with oxygen and is accompanied by systemic findings, which does not match this localized ocular presentation. 2

Essential Ophthalmologic Evaluation

The child requires comprehensive ophthalmologic examination including:

• Slit-lamp biomicroscopy to characterize the pigmentation pattern, assess for iris heterochromia, and evaluate anterior segment structures 1
• Gonioscopy to examine the iridocorneal angle for trabecular meshwork pigmentation, as pigmentary conditions can predispose to glaucoma even in childhood 3, 4
• Intraocular pressure measurement to establish baseline and screen for glaucoma, which can develop in association with ocular melanocytosis 3
• Dilated funduscopic examination using indirect ophthalmoscopy to evaluate for choroidal involvement and optic nerve appearance 1
• Documentation with external photography to establish baseline appearance for future comparison 1

Critical Differential Considerations

Epibulbar choristomas can present as bilateral masses obscuring portions of the eye present from birth, but these are typically raised lesions rather than flat pigmentation. 5 The description of gray-blue discoloration rather than a mass makes this less likely.

Alkaptonuria (ochronosis) causes scleral pigmentation but typically presents later in life and involves other systemic manifestations including dark urine and arthropathy, making it unlikely in an isolated 4-year-old presentation.

Work-Up Algorithm

1. Refer to pediatric ophthalmology for comprehensive examination within 4-6 weeks (non-urgent but should not be delayed) 1

2. Document specific findings for the ophthalmologist:

   • Exact location and extent of pigmentation (outer third bilateral) 1
   • Presence or absence of periocular skin involvement 5
   • Any associated findings (iris heterochromia, vision concerns) 1

3. Establish baseline intraocular pressure as children with ocular pigmentary conditions require lifelong glaucoma surveillance 3, 4

4. Obtain family history of pigmentary conditions, glaucoma, or similar ocular findings, as some pigmentary disorders show familial patterns 3

Long-Term Management Considerations

Children with congenital scleral pigmentation require:

• Annual ophthalmologic examinations with intraocular pressure monitoring throughout childhood and into adulthood, as glaucoma risk persists lifelong 3
• Gonioscopy at regular intervals to monitor for trabecular meshwork pigmentation that may develop or progress 4
• Reassurance to family that isolated scleral melanocytosis is typically a benign cosmetic finding, though surveillance is necessary 1

Common Pitfalls to Avoid

Do not assume this is methemoglobinemia based solely on "gray" discoloration—methemoglobinemia causes diffuse mucosal and skin cyanosis, not isolated scleral changes, and presents with systemic findings. 1, 2

Do not delay ophthalmologic referral assuming this is purely cosmetic—associated glaucoma can develop even in childhood with pigmentary conditions and requires early detection. 3, 4

Do not overlook the need for lifelong surveillance—even if initial examination is reassuring, glaucoma risk persists and requires ongoing monitoring. 3