Is lidocaine (local anesthetic) safe for treating paresthesia in adults with hand, foot, and mouth disease (HFMD)?

Topical Lidocaine is Safe and Appropriate for Paresthesia in Adults with Hand, Foot, and Mouth Disease

Topical lidocaine (2% viscous solution or 5% cream/patch) can be safely used for symptomatic relief of paresthesia and pain in adults with hand, foot, and mouth disease (HFMD), following the same principles established for other mucocutaneous conditions.

Application for Oral Paresthesia

For oral involvement with paresthesia or pain in HFMD:

• Apply viscous lidocaine 2%, 15 mL per application, as a topical anesthetic for oral discomfort 1
• Use before eating to facilitate oral intake when benzydamine hydrochloride provides inadequate pain control 1
• Apply to affected oral areas not more than 3-4 times daily in adults 2
• After applying, wash hands thoroughly with soap and water 2

Application for Cutaneous Paresthesia (Hands and Feet)

For paresthesia affecting the hands and feet:

• Lidocaine 5% cream or patches may be applied to painful areas on hands and feet to enable activities of daily living 1
• Apply patches to intact skin only; up to 3-4 patches can be worn for 12-24 hours per day 3
• Use lidocaine cream for areas where patches may not adhere well or to complement patch coverage 3
• Avoid application to broken or inflamed skin 3

Safety Considerations

Topical lidocaine has an excellent safety profile due to minimal systemic absorption:

• Pharmacokinetic studies demonstrate systemic lidocaine levels remain within safe ranges with up to four patches in 24 hours 3
• Adverse reactions are rare, mild, and mostly limited to local skin reactions 3
• Monitor for signs of systemic absorption (dizziness, confusion, bradycardia), though these are uncommon with topical application 3
• Avoid excessive heat application over treated areas, as this may increase systemic absorption 3

Contraindications

Do not use topical lidocaine in patients with:

• Known hypersensitivity to amide anesthetics 3
• Advanced liver failure 3
• Application sites with broken or inflamed skin (use viscous lidocaine for oral ulcers, but avoid patches on broken skin) 1, 3

Clinical Context for HFMD in Adults

While HFMD predominantly affects children, adult cases are increasingly recognized and often present with atypical symptoms 4, 5:

• Adults typically experience constitutional symptoms, fever, and macular palmoplantar rash with oral/oropharyngeal ulcers 4
• The condition is usually self-limited, lasting less than 1 week 6
• Symptomatic treatment with topical anesthetics follows the same principles as other mucocutaneous conditions 1

Adjunctive Measures

Combine lidocaine with other supportive care:

• Apply white soft paraffin ointment to lips every 2 hours 1
• Use mucoprotectant mouthwashes three times daily for oral ulcers 1
• Consider anti-inflammatory oral rinses containing benzydamine hydrochloride every 3 hours as first-line before escalating to lidocaine 1
• For persistent pain, gabapentinoids (pregabalin 25-50 mg/day or gabapentin 100-200 mg/day as starting doses) may be considered for neuropathic components 1