Hand, foot and mouth disease is an infectious disease caused by enterovirus infection. There are more than 20 types of enteroviruses that can cause hand, foot and mouth disease, among which Coxsackievirus A16 (Cox A16) and enterovirus 71 (EV 71) are more common. It often occurs in children under the age of 5, and the main symptoms include mouth pain, loss of appetite, low fever, and small blisters or ulcers on the hands, feet, and mouth. Most patients recover within a week, but a small number of patients can develop complications such as myocarditis, pulmonary edema, and aseptic meningitis/encephalitis. Some critically ill patients may have a rapid deterioration of their condition, leading to death. Currently, there is a lack of effective medication for treatment.

Etiology

Various enterovirus infections can cause hand, foot, and mouth disease. The most common are Coxsackievirus A16 and enterovirus 71. The modes of infection include the digestive system, respiratory system, and contact transmission.

Clinical symptoms

Hand, foot, and mouth disease is mainly found in children under 5 years old, with an incubation period of 2 to 10 days, averaging 3 to 5 days

1. Main manifestations of general cases

Subacute onset, fever, oral pain, anorexia, scattered herpes or ulcers appear on the oral mucosa, mostly located on the tongue, buccal mucosa, and hard palate, and can also spread to the soft palate, gums, tonsillitis, and pharynx. Rashes appear on the hands, feet, buttocks, arms, and legs, which later become blisters. The surrounding skin of the blisters is inflammatory and pale red, and the blister fluid is less. More on the hands and feet, with palmar surfaces. The number of rashes is few, from several to dozens. There are no traces after disappearance, and no pigmentation. Some cases only mainly manifest as rashes or herpangina. Most cases are cured within a week, with a good prognosis. Some cases have atypical rash manifestations, such as single location or mainly manifested as macules.

2. Main manifestations of critically ill cases

A very small number of cases (especially those under 3 years of age) progress rapidly, with meningitis, encephalitis (encephalitis of the brainstem is more dangerous), encephalomyelitis, pulmonary edema, and circulatory system obstruction appearing in 1 to 5 days, and a few cases are critically ill, which can lead to death, and surviving cases may have complications.

(1) The main manifestations of the central nervous system in cases with concurrent central nervous system diseases are: poor spirits, always wanting to sleep, easy to be startled, headache, vomiting, delirium, and even coma; body tremors, muscular fasciculations, nystagmus, ataxia, and eye movement disorders; fatigue or subacute flaccid numbness; convulsions. Physical examination shows meningeal irritation signs, weakened or disappeared tendon reflexes, and positive Babinski sign. Pneumocentral system diseases are more common in patients under 2 years of age.

(2) The main manifestations of the respiratory tract in cases with concurrent pulmonary edema are: shallow and rapid breathing, difficulty breathing, or changes in breathing rhythm, cyanosis of the lips, cough, coughing up milky, pale pink, or tenacious foam-like sputum; pulmonary rales or wheezing can be heard.

(3) The main manifestations of the respiratory system in cases with concurrent myocarditis are: ashen face, skin texture, cold extremities, cyanosis of fingers (toes); profuse sweating; increased time for capillary refill. Heartbeat becomes faster or slower, pulse rate becomes superficial and rapid or weak, and may even disappear; blood pressure rises or falls.

Examination

Routine physical examination: peripheral blood leukocyte count decreased or normal; urine and stool are generally without abnormalities. Pharyngeal swabs or excreta samples can be collected and sent to the laboratory for virus detection, but hepatitis B detection requires 2 to 4 weeks for results.