Hand, Foot, and Mouth Disease
A common viral illness in children characterized by fever, oral ulcers, and a vesicular rash on the hands and feet.
Emergency Management: Acute cardiopulmonary failure (pulmonary edema, shock) in EV-A71 infection requires immediate intubation, mechanical ventilation, and inotropic support in a PICU.
Hand, foot, and mouth disease (HFMD) is a highly contagious viral illness characterized by a distinct vesicular eruption on the hands, feet, and oral mucosa. It is primarily caused by enteroviruses, most commonly Coxsackievirus A16 and Enterovirus A71. The disease typically affects infants and children under 5 years of age but can occasionally occur in adults.
Detailed Overview
HFMD presents with a brief prodrome of fever, malaise, and sore throat, followed by the development of painful oral enanthemas and maculopapular or vesicular exanthemas on the palms and soles. While Coxsackievirus A16 usually causes mild, self-limiting disease, Enterovirus A71 is associated with more severe neurological complications, such as brainstem encephalitis, aseptic meningitis, and acute flaccid paralysis. Transmission occurs via the fecal-oral route, respiratory droplets, or direct contact with fluid from vesicles. Diagnosis is primarily clinical, though viral culture or PCR can be used in severe cases.
Epidemiology & Demographics
Incidence peaks in late spring to early fall in temperate climates. Extremely common in children <5 years old. Frequent outbreaks occur in daycare centers and schools.
Etiological Mechanism
Most commonly caused by Coxsackievirus A16 and Enterovirus 71 (EV-A71), which belong to the human enterovirus A species of the Picornaviridae family.
Primary Causes
["Coxsackievirus A16 (most common cause of typical, mild HFMD)", "Enterovirus A71 (associated with severe neurological complications and large outbreaks)", "Coxsackievirus A6 (associated with atypical, more extensive rash and onychomadesis)"]
Following ingestion or inhalation, the virus replicates in the lymphoid tissue of the lower intestine and pharynx (tonsils, Peyer patches). This is followed by a primary viremia with spread to regional lymph nodes. A secondary viremia ensues, disseminating the virus to target organs including the skin and mucous membranes, leading to the characteristic vesicular lesions.
Diagnostic Criteria & Guidelines
Clinical diagnosis based on the characteristic presentation of oral ulcers and a vesicular rash on the hands and feet. No specific diagnostic criteria are typically required.
Supportive care. Acetaminophen (10-15 mg/kg PO Q4-6H, max 5 doses/day) or Ibuprofen (10 mg/kg PO Q6-8H, max 40 mg/kg/day) for fever and pain. Maintain hydration.
Second-Line & Adjunctive Therapy
For severe dehydration, hospitalization for IV fluid replacement (e.g., D5 1/2 NS at maintenance rates). IVIG (2 g/kg over 2-5 days) and Milrinone (0.25-0.75 mcg/kg/min) may be used for severe EV71 autonomic nervous system dysregulation or cardiopulmonary failure.
Surgical & Procedural Management
None indicated.
Patient Counseling & Advice
Reassure parents that HFMD is typically self-limiting and resolves in 7-10 days. The child is most contagious during the first week of illness. Emphasize handwashing, especially after changing diapers.
Follow-Up & Monitoring Schedule
Usually not required unless signs of dehydration or neurologic involvement appear.
Preventive Strategies
Strict hand hygiene, especially after diaper changes and using the toilet. Disinfect shared toys and surfaces. Exclude children from daycare/school until fever resolves and lesions are crusted.
Excellent for typical HFMD, with complete recovery in 7-10 days. Onychomadesis (nail shedding) may occur 1-2 months after infection but nails regrow normally. EV-A71 can carry a mortality rate of up to 20% in cases of severe cardiopulmonary compromise.