Differential Diagnosis of Upper Eyelid Rash with Eye Pain and Decreased Vision

Immediate Priority: Rule Out Vision-Threatening Emergencies

The American Academy of Ophthalmology recommends urgent ophthalmology evaluation within 24 hours for patients with eye pain and decreased vision, even with a clear cornea, as the combination of these symptoms with eyelid involvement suggests serious underlying pathology 1
The presence of moderate-to-severe pain with visual changes constitutes red flag features requiring same-day ophthalmology referral, regardless of corneal appearance 1

Herpes Zoster Ophthalmicus presents unilaterally with vesicular dermatomal rash or ulceration of upper eyelid, conjunctival injection, watery discharge, and follicular reaction, and requires immediate ophthalmology referral and systemic antiviral therapy 1
Herpes Simplex Virus Keratouveitis usually presents unilaterally with eyelid involvement, bulbar conjunctival injection, and palpable preauricular lymphadenopathy, and can cause stromal keratitis and uveitis leading to vision loss 1
Orbital or Preseptal Cellulitis requires emergent hospitalization and IV antibiotics, and vision loss in preseptal cellulitis suggests orbital involvement or progression 1, 2
Sebaceous Carcinoma can masquerade as chronic unilateral blepharoconjunctivitis resistant to treatment, and biopsy is indicated for unifocal recurrent lesions, resistance to therapy, focal lash loss, or chronic presentation unresponsive to treatment 1, 2

Atopic Keratoconjunctivitis is a chronic inflammatory keratoconjunctivitis with eyelid and periorbital skin involvement, and can cause punctate epithelial erosions, corneal vascularization, and pannus formation, with a high risk of herpes simplex keratitis or keratouveitis 3

The American Academy of Ophthalmology recommends checking for proptosis, painful/impaired eye movements, fever, or systemic toxicity, and if any are present, immediate hospitalization, contrast-enhanced CT orbits/sinuses, IV antibiotics, and urgent ophthalmology/ENT/ID consultation are required 1, 2
Fluorescein staining is mandatory in every case to detect corneal involvement not clinically apparent, and can show dendritic pattern in HSV keratitis or punctate epithelial keratopathy in atopic disease 1, 3

The American Academy of Ophthalmology recommends never dismissing vision loss as "just dermatitis", and urgent ophthalmology evaluation is required 1
Antiviral therapy should not be delayed if HSV/VZV is suspected, as permanent vision loss can occur rapidly 1
Fluorescein staining should always be performed, even if the cornea appears clear on gross examination 1
Presumed "preseptal cellulitis" should not be treated with oral antibiotics alone if vision is decreased, as this suggests orbital involvement requiring hospitalization 2
Biopsy should be performed on any chronic unilateral eyelid lesion resistant to treatment to rule out malignancy 1, 2