What is the most likely diagnosis and recommended treatment for a painless, 1‑cm nodular redness localized to the temporal bulbar conjunctiva that has recurred intermittently over 6 months, with each episode resolving within a month with or without therapy?

Diagnosis: Nodular Episcleritis

The most likely diagnosis is nodular episcleritis, and the recommended treatment is observation with topical lubricants for mild cases, or topical NSAIDs for persistent symptoms. 1

Clinical Reasoning

The key diagnostic features pointing to nodular episcleritis include:

• Recurrent episodes in the same location over 6 months, with spontaneous resolution within 1 month—this pattern is characteristic of nodular episcleritis, which tends to be more recurrent than simple episcleritis 1
• Painless presentation with localized redness at the temporal bulbar conjunctiva 1
• Self-limited course with or without treatment 1
• 1-cm nodular appearance consistent with the nodular subtype 1

The temporal bulbar location and nodular character distinguish this from simple episcleritis, which presents with more diffuse sectoral redness. 1

Critical Differential Diagnoses to Exclude

While nodular episcleritis is most likely, recurrence in the same location is a warning sign that requires urgent evaluation to exclude malignancy, particularly in elderly patients. 2, 3

Malignant Lesions Requiring Biopsy:

• Conjunctival lymphoma: Presents as painless, indolent "salmon patch" swelling, most commonly on superior or inferior conjunctiva, with up to 20% developing systemic disease 4
• Conjunctival melanoma: Painless, flat or nodular brown or white-pink lesion that can spread to adnexal structures and metastasize 4, 3
• Sebaceous carcinoma: May appear as yellowish subconjunctival multilobulated mass, often misdiagnosed as benign lesions 2, 3

Slit-lamp biomicroscopy is essential to evaluate the location, depth, elevation, and vascular pattern of the lesion. 2

When to Biopsy

Consider biopsy if any of the following are present: 2

• Atypical features (irregular borders, pigmentation changes, intrinsic vessels)
• Enlargement of the lesion over time 2, 3
• Development of new blood vessels or thickening 2, 3
• Elderly patient with history of multiple excisions 2
• Lack of complete resolution between episodes

Treatment Algorithm for Nodular Episcleritis

First-Line Management:

• Cold compresses and artificial tears provide symptomatic relief for mild cases 1
• Observation alone is appropriate if symptoms are minimal, as most attacks resolve within 1-3 months 1

Second-Line for Persistent Symptoms:

• Topical NSAIDs (e.g., ketorolac 0.5% four times daily) for persistent discomfort 1
• Topical corticosteroids may be used for refractory cases, but require ophthalmologic supervision 1

Refractory Cases:

• Systemic NSAIDs or corticosteroids are rarely necessary 1
• Immunosuppressive therapy is reserved for resistant cases with underlying autoimmune disease 1

Ophthalmology Referral Indications

Refer to ophthalmology if: 1, 5

• Severe ocular pain or tenderness (suggests scleritis rather than episcleritis) 1, 5
• Decreased visual acuity 5
• Significant photophobia 5
• Any features suggesting malignancy (see biopsy criteria above) 2
• Failure to resolve within 3 months 1

Workup for Underlying Systemic Disease

Consider rheumatologic workup if episodes are frequent or bilateral, as episcleritis can be associated with systemic autoimmune conditions, though most cases are idiopathic. 1

Common Pitfall

The nodular type of episcleritis is more recurrent and painful than simple episcleritis, and the recurrence in the same location can mimic malignancy. 1 Do not assume benignity based solely on self-resolution—the pattern of recurrence in the identical location over 6 months warrants at minimum slit-lamp examination and consideration of biopsy, especially if the patient is elderly or has atypical features. 2