What is the recommended approach for a focused neuro exam in a patient with eczema herpeticum?

Focused Neurological Examination for Eczema Herpeticum

A focused neurological examination in eczema herpeticum should specifically assess for signs of herpes simplex virus encephalitis, as this represents a potentially life-threatening complication requiring immediate intervention. 1, 2

Key Components of the Neurological Examination

Mental Status Assessment

• Evaluate for altered consciousness, confusion, or behavioral changes that may indicate viral encephalitis 1, 3
• Assess orientation to person, place, and time 1
• Document any memory deficits which may be early signs of herpes encephalitis 1

Cranial Nerve Examination

• Assess for meningeal signs including neck stiffness and photophobia 2, 3
• Evaluate pupillary responses and extraocular movements to detect early cranial nerve involvement 1
• Check facial symmetry and strength as herpes simplex can affect cranial nerves 1

Motor and Sensory Function

• Test for focal motor weakness which may indicate CNS involvement 1, 3
• Assess deep tendon reflexes for asymmetry or hyperreflexia 1
• Evaluate for sensory deficits, particularly if the patient reports unusual sensations 1

Coordination and Gait

• Assess for ataxia or unsteady gait which may indicate cerebellar involvement 1
• Test finger-to-nose coordination to detect subtle neurological deficits 1

Red Flags Requiring Immediate Action

• Fever with altered mental status in a patient with eczema herpeticum requires immediate administration of intravenous acyclovir 1, 2
• Seizures or focal neurological deficits warrant urgent neuroimaging and lumbar puncture to rule out herpes encephalitis 1, 3
• Headache with neck stiffness should prompt consideration of meningitis 2, 3

Diagnostic Workup When Neurological Symptoms Present

• Brain MRI with and without contrast should be performed if neurological symptoms are present 1
• EEG is indicated for patients with altered mental status to rule out subclinical seizures 1
• Lumbar puncture for CSF analysis including HSV PCR testing is essential when encephalitis is suspected 1, 3

Management Considerations

• Early recognition of neurological complications is critical as untreated eczema herpeticum with CNS involvement has a mortality rate of up to 10% 3
• Immediate initiation of intravenous acyclovir has been shown to significantly reduce mortality in patients with eczema herpeticum complicated by encephalitis 1, 2
• Timing of acyclovir initiation directly correlates with length of hospital stay and outcomes 1

Common Pitfalls to Avoid

• Focusing only on skin manifestations while missing subtle neurological signs 3
• Attributing altered mental status to fever alone rather than considering CNS infection 2, 3
• Delaying antiviral therapy while waiting for confirmatory test results in patients with suspected neurological involvement 1, 2
• Failing to recognize that eczema herpeticum can disseminate hematogenously to the central nervous system 3, 4

Remember that eczema herpeticum is a dermatological emergency that can rapidly progress to systemic complications including encephalitis, requiring prompt recognition and treatment 2, 3.