Herpes Zoster Ophthalmicus (Shingles) Until Proven Otherwise
This presentation of eyelid lesions with ipsilateral facial numbness is herpes zoster ophthalmicus (HZO) until proven otherwise, and requires urgent ophthalmology referral within 24-72 hours to prevent vision-threatening complications.
Primary Diagnostic Consideration
The combination of eyelid lesions with cheek numbness in a dermatomal distribution is pathognomonic for varicella zoster virus (VZV) reactivation affecting the ophthalmic division of the trigeminal nerve 1. HZO accounts for 4-20% of all herpes zoster cases and leads to ocular involvement in approximately 50% of patients, with up to 25% developing chronic or recurrent disease 2.
Key Clinical Features to Confirm HZO:
- Vesicular dermatomal rash or ulceration of the eyelids - the distinctive sign that differentiates HZO from other causes 1
- Unilateral presentation respecting the midline, typically involving the forehead, upper eyelid, and nose 1
- Hutchinson's sign (lesions on the tip of the nose) indicates nasociliary nerve involvement and predicts higher risk of ocular complications 2
- Numbness or altered sensation in the affected dermatome precedes or accompanies the rash 3
Why This Matters for Vision and Life
Ocular Complications (Morbidity):
HZO can cause conjunctivitis, keratitis, uveitis, and less commonly optic neuropathy or retinitis 2. The guideline specifically warns that recurrent disease can lead to keratitis of the epithelium or stroma with subsequent scarring, late corneal anesthesia, dry eye, and retinitis 1.
Critical Pitfall - Malignancy Masquerading as Infection:
Facial numbness presenting to ophthalmology carries a 57% mortality rate in case series, with 71% caused by neoplastic pathology 3. While HZO is the most likely diagnosis with vesicular lesions, the presence of facial numbness without the characteristic rash, or unilateral chronic presentation unresponsive to therapy, should raise suspicion for perineural spread from squamous cell carcinoma (36% of facial numbness cases) or sebaceous carcinoma 4, 3.
Immediate Management Algorithm
Step 1: Confirm HZO Diagnosis
- Look for vesicular dermatomal rash or ulceration on the eyelids and forehead 1
- Check for Hutchinson's sign (nasal tip involvement) 2
- Document the distribution of numbness (should follow V1 dermatome) 2, 5
Step 2: Assess for Ocular Involvement
- Visual acuity testing is mandatory 6
- Check for conjunctival injection, corneal involvement with fluorescein staining, and anterior chamber reaction 1, 7
- Document any epithelial defects, stromal infiltrates, or keratitis 7
Step 3: Initiate Antiviral Therapy
Early recognition and timely treatment with antivirals may prevent ocular complications 2. Start oral antivirals (acyclovir, valacyclovir, or famciclovir) within 72 hours of rash onset 2, 5.
Step 4: Urgent Ophthalmology Referral
Due to the potential for vision impairment, ocular involvement requires urgent ophthalmic consultation 2. Refer within 24-72 hours even if no obvious ocular signs are present, as complications can develop 2, 5.
Red Flags Requiring Alternative Diagnosis Consideration
When to Suspect Malignancy Instead:
- Marked asymmetry or chronic unilateral presentation unresponsive to standard therapy 4
- Loss of normal eyelid margin anatomy or focal lash loss 4
- Absence of vesicular rash despite facial numbness 3
- Conjunctival cicatricial changes in the affected eye 4
If any of these features are present, biopsy is indicated to rule out sebaceous carcinoma or perineural spread from squamous cell carcinoma 4, 3.
Prevention of Future Episodes
Both recombinant adjuvanted vaccine (RZV/Shingrix) and live-attenuated vaccine significantly reduce the incidence of HZ and HZO in older adults, with RZV being more effective 2. Vaccination is recommended even after an episode of HZO, though data on preventing recurrent disease are limited 2.