Unilateral Flaking Dry Lower Eyelid: Autoimmune Differential Diagnosis
Discoid lupus erythematosus (DLE) is the primary autoimmune disease that presents with unilateral flaking, dry lower eyelid involvement, often mimicking chronic blepharitis that fails to respond to conventional treatment. 1, 2
Primary Diagnostic Consideration: Discoid Lupus Erythematosus
Lower eyelid involvement occurs in approximately 6% of patients with DLE and can be the presenting or sole manifestation of the disease. 2, 3 The clinical presentation is distinctive:
- Edematous, erythematous plaques on the lower eyelid with scaling and flaking 1, 2
- Unilateral presentation is well-documented, though bilateral involvement can occur 1, 4
- May be associated with madarosis (eyelash loss) without preceding scarring 2
- Often misdiagnosed as chronic blepharitis that persists despite standard treatment with ophthalmic medications and eyelid hygiene 1, 2, 3
Diagnostic Approach
Obtain a full-thickness eyelid biopsy for histopathological examination and direct immunofluorescence studies to confirm DLE diagnosis. 1, 2, 4 This is critical because:
- Clinical features alone are insufficient for diagnosis 1
- Histopathology shows interface dermatitis with basement membrane thickening, follicular plugging, and dermal mucin deposition 2
- Direct immunofluorescence demonstrates immunoglobulin and complement deposition at the dermal-epidermal junction 4
Check ANA (antinuclear antibody), anti-dsDNA, anti-Ro/SSA, and anti-La/SSB antibodies to evaluate for systemic lupus erythematosus (SLE). 5, 4 While localized DLE may have negative or low-titer ANA, this workup is essential because:
- Unilateral facial involvement can be a rare presenting sign of SLE 5
- Patients with widespread DLE have higher risk of developing SLE 2
- Early identification prevents progression to systemic disease 5
Treatment Algorithm
Initiate hydroxychloroquine 400 mg daily as first-line systemic therapy. 2, 4 This recommendation is based on:
- Documented efficacy in resolving eyelid lesions with minimal scarring 2
- Moderate improvement typically seen within 3 months 4
- Prevention of progression to conjunctival scarring or symblepharon formation 1
Add topical corticosteroids and sun protection as adjunctive measures. 2 However, note that:
- Corticosteroid eye drops alone are ineffective for DLE-related eyelid involvement 2
- Systemic therapy is required for disease control 2, 4
Secondary Consideration: Sjögren's Syndrome
While Sjögren's syndrome causes dry eyes, it typically presents bilaterally with aqueous tear deficiency rather than unilateral eyelid flaking. 6 However, consider this diagnosis if:
- Patient has concurrent dry mouth (xerostomia) 6
- Symptoms include arthralgia, myalgia, or fatigue 6
- Patient is a non-elderly woman with rapid onset or marked severity of tear deficiency 6
Perform Schirmer test (≤5 mm/5 minutes), check anti-SSA/Ro and anti-La/SSB antibodies, and measure unstimulated salivary flow rate (≤0.1 ml/minute) if Sjögren's syndrome is suspected. 6, 7
Co-manage with rheumatology due to 5% lymphoma risk and potential systemic complications. 6, 8
Critical Pitfalls to Avoid
Do not continue treating as simple blepharitis beyond 4-6 weeks without biopsy if symptoms persist. 1, 2, 3 Delayed diagnosis leads to:
- Eyelid margin deformities requiring complex reconstruction 3
- Progression to conjunctival scarring or symblepharon 1
- Missed opportunity to diagnose systemic lupus 5, 3
Do not assume bilateral presentation is required for autoimmune disease. 5, 1, 4 Unilateral involvement is well-documented in DLE and can be the sole manifestation for years before systemic features develop.
Do not overlook the possibility of SLE when DLE is diagnosed. 5, 2 Check for oral ulcers, proteinuria, thrombocytopenia, and abnormal ANA titers to identify systemic disease requiring more aggressive management.