What are the symptoms and treatment of Hand, Foot, and Mouth Disease (HFMD)?

Hand, Foot, and Mouth Disease: Clinical Presentation and Management

Visual Characteristics and Clinical Presentation

HFMD presents with a highly characteristic distribution of small pink macules that evolve into vesicular lesions, primarily affecting the palms, soles, and oral mucosa. 1, 2

Initial Symptoms (First 1-3 Days)

• Fever is typically the first symptom, usually low-grade but can exceed 102.2°F (39°C), accompanied by malaise, irritability, and sore throat 2
• Constitutional symptoms include general discomfort, myalgia, and occasionally respiratory symptoms (cough, rhinitis) 2, 3
• Gastrointestinal symptoms (nausea, vomiting, diarrhea) may occur in some toddlers 2

Characteristic Rash Pattern (Days 2-4)

• The exanthem begins as small, blanching pink macules on the hands, feet, and oral mucosa that evolve to vesicular lesions 4, 2
• Oral lesions appear as painful vesicles and ulcers on the tongue, gums, and inside of cheeks 1, 5
• Hand and foot lesions are tender vesicles concentrated on palms and soles, though may extend to legs and buttocks 1, 3
• Unlike chickenpox, vesicles are concentrated rather than widely distributed 2

Atypical Presentations

• Widespread exanthema beyond classic distribution may occur, particularly involving the legs and buttocks 1, 6
• Children with atopic dermatitis may develop "eczema coxsackium" where eczematous skin becomes superinfected, resembling herpes infection 5, 6
• Nail changes (onychomadesis/nail shedding) can occur 3-8 weeks after infection 5, 6

Diagnostic Approach

Diagnosis is primarily clinical based on the characteristic distribution of vesicular lesions. 1

When Laboratory Confirmation is Needed

• Reverse transcriptase PCR (RT-PCR) targeting the 5' non-coding region is the preferred diagnostic method 1
• Vesicle fluid samples have the highest viral loads and are ideal for testing 1
• Respiratory samples or stool specimens can be used when vesicle fluid is unavailable 1

Critical Differential Diagnoses

• Distinguish from herpes simplex virus infection, as HSV has available antiviral treatment whereas HFMD does not 1
• Rule out drug hypersensitivity reactions, which can also present with palmar-plantar rash 4, 2
• Consider syphilis, meningococcemia, and Rocky Mountain spotted fever in atypical presentations with palmar-plantar involvement 2
• Differentiate from Kawasaki disease (HFMD has vesicular lesions vs. diffuse erythema) 2

Treatment and Management

Treatment is entirely supportive, as no specific antiviral therapy exists for HFMD. 1, 3, 5

Pain and Fever Management

• Use oral acetaminophen or NSAIDs for limited duration to relieve pain and reduce fever 1
• Avoid aspirin in children due to Reye's syndrome risk 1

Oral Lesion Management

• Apply white soft paraffin ointment to lips every 2 hours to prevent drying and cracking 1
• Clean mouth daily with warm saline mouthwashes 1
• Apply benzydamine hydrochloride oral rinse or spray every 3 hours, particularly before eating 1
• Use chlorhexidine oral rinse twice daily as antiseptic 1
• For severe oral involvement, consider betamethasone sodium phosphate mouthwash four times daily 1
• Use mild toothpaste and gentle oral hygiene 1

Hand and Foot Lesion Management

• Apply intensive skin care with moisturizing creams, particularly urea-containing products 1
• Use zinc oxide as a protective barrier to soothe inflamed areas and reduce itchiness 1
• Apply zinc oxide in thin layers after gentle cleansing; reapply as needed 1
• For nighttime relief, apply zinc oxide followed by loose cotton gloves to enhance effectiveness 1
• Avoid friction and heat exposure to affected areas 1

Management of Open Sores on Feet

• Wash feet daily with careful drying, particularly between toes 1
• Wear appropriate cushioned footwear; avoid walking barefoot 1
• Do not soak feet in footbaths, as this induces skin maceration 1
• Monitor for signs of secondary bacterial infection: increased redness, warmth, purulent drainage, or worsening pain 1
• Treat any secondary bacterial infections that develop 1
• Reassess after 2 weeks if lesions are not improving 1

Critical Pitfalls to Avoid

• Do not use chemical agents or plasters to remove corns or calluses 1
• Do not routinely use topical antiseptic or antimicrobial dressings for HFMD foot lesions 1
• Avoid applying zinc oxide to open or weeping lesions 1

Prevention and Infection Control

Hand hygiene with soap and water is the most important preventive measure and is more effective than alcohol-based hand sanitizers. 1

Environmental Measures

• Clean toys and objects that may be placed in children's mouths 1
• Avoid sharing utensils, cups, or food 1
• Follow standard precautions and good hand hygiene in healthcare settings 1

Return to Daycare/School Guidelines

Children can return to daycare once fever has resolved and mouth sores have healed, even if skin rash is still present. 1

• Exclusion based solely on healing skin lesions is unnecessary 1
• By the time HFMD is diagnosed, the child has likely been shedding virus for weeks 1
• Children should avoid close contact with others until fever resolves and mouth sores heal 1

Severe Complications and Red Flags

Enterovirus 71 (EV-A71) is associated with more severe outbreaks and neurological complications, particularly in Asia. 1, 3, 7

Neurological Complications Requiring Immediate Evaluation

• Meningoencephalitis and brainstem encephalitis (70% of neurological complications) 7
• Acute flaccid myelitis (AFM) 1
• Acute flaccid paralysis (AFP) 1
• Warning signs: severe headache, altered mental status, myoclonic jerks, seizures, persistent vomiting 7

High-Risk Populations

• Immunocompromised patients may experience more severe disease and require close monitoring 1, 8
• Children under 5 years are at highest risk for complications 3, 7

Follow-Up

• If evidence of infection has not resolved after 4 weeks, re-evaluate and consider alternative diagnoses 1
• Monitor for delayed nail changes (onychomadesis) 3-8 weeks post-infection 5