Hand Foot Mouth Disease Causing Fourth Nerve Palsy and Acute Maculopathy in Adult Male Patient

This case report describes a rare presentation of Hand, Foot, and Mouth Disease (HFMD) in an adult male who developed right fourth nerve palsy and acute maculopathy with sub-macular edema in the left eye. Published in the Journal of Clinical Research and Clinical Case Reports in 2023, the study highlights uncommon neuro-ophthalmic and retinal complications of HFMD in adults that clinicians should consider when evaluating patients with recent viral illness and new-onset visual symptoms.

Background

Hand, Foot, and Mouth Disease is a common viral infection caused by the coxsackievirus, a member of the enterovirus family. It predominantly affects children under 5 years of age, presenting with low-grade fever, sore throat, and characteristic vesicular rashes on the hands, feet, and mouth. The disease typically resolves within 7 to 10 days without medical intervention.

While HFMD is rare in adults, those who do become infected are often misdiagnosed because of the low clinical suspicion for this typically pediatric disease. Ocular complications of HFMD in adults have been reported only in isolated case reports, primarily involving unilateral acute idiopathic maculopathy. Cases involving cranial nerve palsy from HFMD are exceedingly rare, with only a few reports in the literature describing encephalitis-related diplopia from enterovirus infection. Prior to this case, the combination of both fourth nerve palsy and acute maculopathy had not been described in an adult with HFMD.

The Patient

A 31-year-old male with no significant prior medical history presented with:

• Red spots on hands consistent with HFMD lesions
• Headaches
• Blurry vision
• Vertical diplopia (double vision)
• History of his son recently being diagnosed with HFMD at daycare

The patient did not experience any encephalopathic symptoms such as tremor, unsteadiness, or stiffness, which have been reported in severe adult HFMD cases.

Diagnostic Workup

Visual Acuity and Exam Findings

• Visual acuity: 20/20 in both eyes with correction
• Color vision: 11/11 OD (right eye), 10/11 OS (left eye) -- mildly reduced in the left eye
• Intraocular pressure: 12 mmHg OD, 11 mmHg OS (within normal limits)
• Visual field testing: Scattered scotoma in the left eye
• Sensorimotor exam: 3 prism diopters right hypertropia in primary gaze, increased in left gaze and right head tilt, consistent with right fourth nerve palsy

Retinal Imaging

• OCT of the macula: Sub-macular fluid in the left eye with central macular thickness significantly elevated
• Dilated fundus examination: Roth spot (retinal hemorrhage with white center) in the left eye, indicating systemic illness
• OCT of the optic nerve: Normal retinal nerve fiber layer (RNFL) thickness -- 104 microns OD and 107 microns OS

Neuroimaging and Laboratory Studies

• MRI of the brain and orbits: Normal, ruling out compressive lesions
• Bloodwork: Normal except for mildly elevated erythrocyte sedimentation rate (ESR), consistent with recent viral infection

Findings

Treatment Protocol

Based on the clinical presentation and the temporal relationship to HFMD infection, the patient was started on:

1. Valacyclovir (antiviral): 1 gram three times daily for 21 days
2. Prednisone (oral steroid, started 3 days after antiviral): 60 mg initially, tapering down by 10 mg every 3 days

Two-Week Follow-Up Results

• Diplopia resolved in primary gaze and right gaze, with residual 3 prism diopters right hypertropia only in left gaze
• OCT of the macula: Complete resolution of sub-retinal fluid in the left eye
• Fundus photography: Macular scar present in the left eye
• Patient status: Being monitored and expected to make a full recovery

Clinical Significance

This case is significant for several reasons:

• It represents one of the first reported cases where HFMD simultaneously caused both cranial nerve palsy (fourth nerve) and acute maculopathy in an adult patient
• The rapid response to combination antiviral and steroid therapy suggests an inflammatory or direct viral mechanism for the ocular complications
• It underscores the importance of obtaining a thorough history of recent infections, including those in household contacts, especially in patients presenting with unexplained diplopia or visual field deficits
• The presence of a Roth spot serves as an important clinical clue pointing toward a systemic infectious process

In the literature review, several other adult HFMD cases with maculopathy were identified, but none exhibited concurrent nerve palsy. Prior reports included patients aged 24 to 41 years with findings such as subretinal exudate, ellipsoid layer disruption, outer retinitis, and macular hemorrhage. Most cases resolved spontaneously or with oral steroid treatment, though some left residual macular scarring.

Citation

Khachikyan N, Manasyan A, Gaytan S, Hashemi N. Hand Foot Mouth Disease Causing Fourth Nerve Palsy and Acute Maculopathy in Adult Male Patient: A Case Report and Review Literature. Clinical Research and Clinical Case Reports. 2023;4(1). DOI: 10.2023/1.1063

References