Overview
Definition:
Hand-foot-and-mouth disease (HFMD) is a common, contagious viral illness typically affecting infants and young children
It is characterized by fever, malaise, and a characteristic rash primarily on the hands, feet, and in the mouth.
Epidemiology:
HFMD is most common in summer and autumn, though outbreaks can occur year-round
It is caused by several strains of enteroviruses, most notably coxsackievirus A16 and enterovirus 71 (EV71)
Transmission occurs through direct contact with respiratory secretions, blister fluid, or fecal-oral routes.
Clinical Significance:
While typically a mild illness, HFMD is important for DNB and NEET SS candidates to understand due to its high prevalence in pediatric populations, potential for outbreaks, and rare but serious neurological complications, particularly with EV71 infection
Effective symptomatic management, especially hydration and pain relief, is crucial for patient comfort and preventing dehydration.
Clinical Presentation
Symptoms:
Fever typically appears first, followed by sore throat and loss of appetite
Within 1-2 days, painful sores appear in the front of the mouth
A non-itchy rash with small red spots, some blistering, develops on the palms of the hands and soles of the feet
It may also appear on the knees, elbows, buttocks, or genital area
Children may be irritable due to pain and discomfort.
Signs:
Macular or papular rash on palms and soles
vesicular or ulcerative lesions on oral mucosa (tongue, gums, buccal mucosa)
mild cervical lymphadenopathy
low-grade fever
Vital signs are usually normal unless complications arise.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on the characteristic rash distribution and oral lesions in a febrile child
No specific laboratory tests are routinely required for diagnosis, though viral PCR from throat or stool specimens can confirm the causative enterovirus in severe cases or outbreaks.
Diagnostic Approach
History Taking:
Enquire about onset of fever, sore throat, rash development and distribution, appetite, oral intake, and any recent exposure to sick contacts
Assess for signs of dehydration
Red flags include neurological symptoms (seizures, lethargy, ataxia), respiratory distress, or severe vomiting.
Physical Examination:
Examine for fever
assess oral mucosa for characteristic vesicles and ulcers
inspect hands and feet for maculopapular or vesicular rash
check for lesions on buttocks, knees, and elbows
palpate for lymphadenopathy
evaluate hydration status (mucous membranes, skin turgor, urine output).
Investigations:
Investigations are generally not required for uncomplicated HFMD
In severe cases or during outbreaks, viral isolation and typing may be performed by PCR on throat swabs, stool, or cerebrospinal fluid (if meningitis is suspected)
Complete blood count may show mild leukocytosis
Electrolytes and renal function tests may be helpful if dehydration is suspected.
Differential Diagnosis:
Other conditions with vesicular or ulcerative oral lesions and rash include herpangina (lesions predominantly on posterior pharynx), varicella (generalized rash, vesicles on trunk and limbs), herpes simplex stomatitis (more severe oral lesions, systemic symptoms), allergic reactions, and impetigo
The characteristic distribution of rash on hands and feet is key to diagnosing HFMD.
Management
Initial Management:
The primary goal is symptomatic relief and preventing complications
This involves encouraging fluid intake to prevent dehydration and managing fever and pain.
Hydration:
Adequate fluid intake is paramount
Offer frequent small sips of cool liquids such as water, diluted fruit juices (avoid acidic ones like orange juice that can irritate mouth sores), or oral rehydration solutions (ORS)
For infants, continue breastfeeding or formula feeding as tolerated
Monitor urine output closely
decreased output is an early sign of dehydration
Severe dehydration may require intravenous fluid resuscitation.
Pain And Fever Control:
Analgesics like paracetamol (acetaminophen) or ibuprofen can be used to manage fever and pain
Dosing should be age and weight-appropriate according to standard pediatric guidelines
Topical oral anesthetic gels or sprays may provide temporary relief for mouth sores, but caution is advised to avoid gagging or aspiration in younger children
Offer soft, bland foods and cold liquids to ease swallowing.
Supportive Care:
Maintain comfort through rest and a calm environment
Good hand hygiene by caregivers is essential to prevent spread
Monitor for signs of complications such as dehydration, neurological involvement (encephalitis, meningitis), or myocarditis
Isolation of affected children during the highly contagious phase (when blisters are present) is recommended.
Complications
Early Complications:
The most common complication is dehydration due to painful oral ulcers leading to reduced fluid intake
Neurological complications are rare but serious, including aseptic meningitis, encephalitis, acute flaccid paralysis (especially with EV71), and Guillain-Barré syndrome.
Late Complications:
Rarely, post-infectious sequelae or persistent neurological deficits can occur following severe EV71 infection
Nail changes (onychodystrophy) or nail loss can occur a few weeks after the rash resolves but are generally transient.
Prevention Strategies:
Good hygiene practices, including frequent handwashing with soap and water, especially after changing diapers and using the toilet, are critical
Avoid close contact with infected individuals
Prompt identification and isolation of symptomatic individuals can limit outbreaks in schools and childcare settings.
Prognosis
Factors Affecting Prognosis:
Prognosis is generally excellent for most cases caused by coxsackievirus A16, with full recovery within 7-10 days
Cases caused by enterovirus 71 have a higher risk of severe neurological and systemic complications, which can lead to significant morbidity or mortality.
Outcomes:
Most children recover fully with supportive care
Severe complications are uncommon
Long-term sequelae are rare, primarily associated with EV71 infection.
Follow Up:
Routine follow-up is not typically required for uncomplicated HFMD
However, children with severe complications or suspected neurological involvement need close medical supervision and follow-up by specialists.
Key Points
Exam Focus:
DNB/NEET SS candidates should focus on the clinical presentation, distinguishing features from herpangina and other vesicular rashes, and the management of hydration and pain
Recognize EV71 as a potential cause of severe neurological complications.
Clinical Pearls:
Emphasize maintaining hydration by offering fluids frequently and in small amounts
Avoid acidic or salty foods that can exacerbate oral pain
Monitor urine output as a key indicator of hydration status
Educate parents on hygiene practices to prevent spread.
Common Mistakes:
Overlooking early signs of dehydration in infants and young children
Inadequate pain management leading to poor oral intake
Misdiagnosing HFMD due to atypical rash presentations or confusion with other viral exanthems
Failure to consider EV71 in cases with neurological signs.