Hand, foot, and mouth disease in Child
HFMD is highly contagious and commonly transmitted in day care centers, schools, summer camps, and hospitals. Transmission of HFMD occurs via the fecal-oral route and through secretions, including secretions of vesicular fluid and nasal / oral fluid. Following infection, individuals can shed the virus via gastrointestinal passage for 4-6 weeks or via the upper respiratory tract for 3 weeks. Outbreaks usually occur from June to October. The incubation period for the virus is approximately 3-6 days.
HFMD primarily affects children, but adults can also develop the disease. Prodromal symptoms may include fever, abdominal pain, fussiness, emesis, and diarrhea. The typical course of infection starts with a mild fever, sore throat and mouth, cough, headache, malaise, diarrhea / vomiting, and occasional arthralgias. One to two days after the start of systemic symptoms, small oral macules can develop into vesicles and ultimately ulcerate. Lesions then develop on the hands, feet, and groin and can eventually become more widespread. Patients may have associated submandibular and cervical lymphadenopathy.
Coxsackievirus A6 (CV-A6) may cause atypical HFMD where more extensive vesicle formation, including on the forearms and in the perioral area, is seen. "Tomato flu" is an atypical presentation of HFMD that has been noted to occur in children in Kerala, India. Tense vesicles of differing sizes are seen on the extremities, including palms and soles. Oral lesions may occur. Coxsackievirus A16 (CV-A16) has been isolated in 2 known cases.
HFMD from enterovirus A71 (EV-A71) can result in uncommon, severe sequelae, including encephalitis, interstitial pneumonia, flaccid paralysis, myocarditis, heart failure, meningoencephalitis, pancreatitis, conjunctival ulceration, and spontaneous abortion. Lesions are more likely to present on atypical sites such as the face, scalp, and ankles or diffusely on the whole body. Some patients may develop persistent myalgia / arthralgia. Complications are more severe under the age of 1 or with EV-A71 infection.
Eczema coxsackium refers to the spread of a coxsackie viral exanthem in an underlying rash, most commonly atopic dermatitis. Widespread vesicles may be seen more frequently in this setting.
B08.4 – Enteroviral vesicular stomatitis with exanthem
266108008 – Hand foot and mouth disease
Differential Diagnosis & Pitfalls
- Varicella – Vesicles develop from papules in crops over face, trunk, and extremities.
- Dyshidrotic dermatitis – Typically, chronic dermatitis that presents as deep-seated, very pruritic vesicles involving the sides of the fingers.
- Gianotti-Crosti syndrome – Symmetrically distributed monomorphous, pink-brown, flat-topped papules or papulovesicles 1-10 mm in diameter on the face, extensor limbs, and buttocks.
- Erythema multiforme – Target lesions seen on palms or extensor extremities. Patients can have co-existing herpes labialis.
- Mpox – Umbilicated vesicles and pustules that may be localized or scattered and generalized.
- Primary herpes gingivostomatitis – 2-4 mm vesicles, erosions, or ulcers are scattered broadly over the area of primary infection or they may coalesce. Cutaneous findings are absent.
- Herpangina – Almost identical to HMFD in systemic presentation with a flu-like illness and mouth ulcers, but herpangina does not exhibit vesicles on the palms, soles, digits, and other skin sites.
- Aphthous ulcers – Painful, shallow ulcers on a grayish base without vesicle formation.
- Streptococcal throat infection
- Oral candidiasis
- Meningococcemia – Purpura and pustules.
- Rocky Mountain spotted fever – Purpura, lesions are not vesicular or eroded.
- Subacute bacterial endocarditis – Purpura.
- Leukocytoclastic vasculitis – Rare on the palms.