Hand, foot and mouth disease is an acute infectious disease caused by enteroviruses (CoxA16, EV71), mostly occurring in preschool children, with the highest incidence in the under-3 age group. The main symptoms are maculopapular rash and herpes on the hands, feet and mouth, and in a few severe cases, meningitis, encephalitis, encephalomyelitis, pulmonary edema and circulatory disorders, mostly caused by EV71 infection, and the main cause of death is severe brainstem encephalitis and neurogenic pulmonary edema. Patients and latently infected persons are the source of infection, which is mainly transmitted through the gastrointestinal tract, respiratory tract and close contact.
I. Clinical manifestations
(A) Common case manifestations.
Acute onset, fever, scattered herpes on the oral mucosa, maculopapular rash and herpes on the hands, feet and buttocks, there may be inflammatory redness around the herpes, and less fluid in the herpes. It may be accompanied by cough, runny nose, and loss of appetite. Some cases present only with a rash or herpetic pharyngitis. The prognosis is good.
(ii) Presentation of severe cases.
A few cases (especially those younger than 3 years old) may develop meningitis, encephalitis, encephalomyelitis, pulmonary edema, circulatory disorders, etc. The condition is vicious and can lead to death or sequelae.
1, neurological system: poor mental health, drowsiness, easily startled; headache, vomiting; limb myoclonus, nystagmus, ataxia, eye movement disorders; weakness or acute flaccid paralysis; convulsions. Physical examination can be seen as meningeal stimulation signs, weakened or absent tendon reflexes; critical cases may show coma, cerebral edema, encephalopathy.
2, respiratory system: shallow breathing, respiratory distress or rhythm changes, lip cyanosis, oral vomiting of white, pink or bloody foam (sputum); lungs can be heard in the wet nymphal woven
3.Circulatory system: pale gray face, florid skin, cold extremities, cyanosis of fingers (toes); cold sweat; increased or slowed heart rate, shallow pulse or weakened or even disappeared; increased or decreased blood pressure.
Second, laboratory tests
(A) Blood routine.
Leukocyte count is normal in common cases, and can be significantly increased in severe cases.
(B) Blood biochemical examination.
Some cases may have mildly elevated ALT, AST, CK? -MB may be elevated, and in severe cases, troponin (cTnI) and blood glucose may be elevated.
(iii) Cerebrospinal fluid examination.
The following abnormalities may be present in neurological involvement: clear appearance, increased pressure, increased white blood cells, normal or mildly increased protein, normal sugar and chloride.
(iv) Pathogenetic examination.
Positive enterovirus (CoxA16, EV71, etc.) specific nucleic acid or isolation of enterovirus. The rate of positive pharyngeal and airway secretions, herpes fluid, and stool is high. Specimens should be retained in a timely and standardized manner and sent for testing as soon as possible.
(E) Serological examination.
There is more than 4-fold increase in serum EV71, CoxA16 or other enterovirus neutralizing antibodies during the acute and recovery periods.
III. Physical examination
(A) Chest radiograph.
It may show increased texture of both lungs, grid-like and patchy shadows, pulmonary edema and pulmonary hemorrhage signs may appear in severe cases, and some cases are unilateral.
(B) Magnetic resonance imaging.
There may be abnormal changes in neurological involvement, with brainstem and spinal cord gray matter damage predominant.
(iii)Electroencephalogram.
Some cases may show diffuse slow waves, and a few may show spiky (sharp) slow waves.
(iv) Echocardiography.
Decreased left ventricular ejection fraction, reduced left ventricular systolic motion, and mitral or tricuspid regurgitation.
(v) Electrocardiogram.
No specific changes. Sinus tachycardia or bradycardia, prolonged Q to T interval, and ST to T changes may be seen.
IV. Diagnostic criteria
(A) Clinical diagnosis of the case.
Onset in the epidemic season, common in preschool children, infants and young children are more common.
1. Common cases: fever with rash on hands, feet, mouth and buttocks; some cases may be feverless.
2.Severe cases: neurological involvement, respiratory and circulatory dysfunction, etc. Laboratory tests may include increased peripheral blood leukocytes, abnormal cerebrospinal fluid, increased blood glucose, and abnormal EEG, cerebrospinal magnetic resonance, chest X-ray, and echocardiography. In a very few severe cases, the rash is atypical and the clinical diagnosis is difficult and needs to be made in combination with pathogenic or serological examination.
If there is no rash, the clinical diagnosis of HFMD is not appropriate.
(B) Confirmed cases.
Clinical diagnosis can be confirmed if the case has one of the following.
1. Positive specific nucleic acid test for enterovirus (CoxA16, EV71, etc.).
2.Enterovirus was isolated and identified as EV71, CoxA16 or other enterovirus that can cause HFMD.
3.Serum EV71, CoxA16 or other enteroviruses that can cause HFMD have more than 4-fold increase in neutralizing antibody during the acute and recovery periods.
V. Differential diagnosis
(A) Common cases.
It needs to be differentiated from other childhood rash diseases, such as herpetic urticaria, chickenpox, atypical measles, early childhood emergency rash, and rubella. Epidemiological characteristics, rash pattern, location, time of rash and presence of lymph node enlargement can be distinguished, with the rash pattern and location being the most important.
(B) Severe cases.
1. Differentiation from other central nervous system infections
(l) The manifestations of CNS infections caused by other viruses can be similar to those of severe HFMD. For those with an atypical rash, specimens should be retained for virological examination of enteroviruses, especially EV71, as soon as possible, and the diagnosis should be made in combination with pathogenic or serological examination. At the same time, refer to the disposition process of serious cases of HFMD for diagnosis, treatment and management.
(2) Those with delayed paralysis as the main symptom should be differentiated from poliomyelitis.
2. Differentiation from severe pneumonia
Severe HFMD can occur as neurogenic pulmonary edema, which should be differentiated from severe pneumonia. The former cough symptoms are relatively mild, the condition changes rapidly, shallow breathing in the early stage and dyspnea in the late stage, white, pink or bloody foamy sputum may appear, and the chest X-ray shows pulmonary edema.
3, circulatory disorders as the main manifestation should be distinguished from fulminant myocarditis, infectious shock, etc.
Early identification of severe cases
Patients with the following characteristics, especially those under 3 years of age, may develop into critical cases within a short period of time, and should be closely observed for changes in condition, necessary auxiliary examinations, and targeted rescue work.
(A) Persistent high fever that does not subside.
(B) Poor mental health, vomiting, limb myoclonus, limb weakness and convulsions.
(C) Increased respiration and heart rate.
(iv) Cold sweating, poor peripheral circulation.
(V) Hypertension or hypotension.
(vi) Significant increase in peripheral blood leukocyte count.
(vii) Hyperglycemia.
VII. Disposition process
The outpatient physician should carefully inquire into the medical history, focusing on whether there are similar cases in the vicinity and the history of exposure and treatment; pay attention to the rash, vital signs, neurological and pulmonary signs during physical examination.
(a) Clinical diagnosis cases and confirmed cases are reported according to the requirements of infectious disease category C in the Prevention and Control of Infectious Diseases Act.
(ii) Common cases can be treated on an outpatient basis and patients and families are informed to follow up when their condition changes.
(c) Children under 3 years of age with persistent fever, poor mental health, vomiting, and illness within 5 days should be kept under observation. Closely observe changes in the condition during the observation period, especially the function of the heart, lungs, brain and other important organs, and give targeted treatment according to the condition.
If the condition of the patient is eligible for hospitalization during the observation period, the patient should be hospitalized immediately, and the patient can be released from observation if the condition improves within 48 hours.
(d) Those with one of the following conditions should be hospitalized
1.Drowsiness, easy to startle, restlessness, convulsions.
2. Myoclonus, weakness or paralysis of limbs.
3.Shallow and difficult breathing.
4.Pale face, cold sweat, increased or decreased heart rate (not proportional to the degree of fever), poor peripheral circulation.
Those with one of the above 3 or 4 should be admitted to ICU for treatment.
VIII. Treatment
(A) Common cases.
1. General treatment: pay attention to isolation and avoid cross-infection. Proper rest, light diet, good oral and skin care.
2, symptomatic treatment: fever and other symptoms are treated with a combination of Chinese and Western medicine.
(II) Serious cases.
1.Treatment of neurological involvement
(1) Control intracranial hypertension: limit the intake, give mannitol 0.5-1.0g/kg?times, every 4-8 hours, 20?~30min intravenously, adjust the interval of drug administration and dose according to the condition. If necessary, add tachyphylaxis.
(2) Intravenous immunoglobulin, total 2g/kg, given in 2 to 5 days.
(3) Apply glucocorticoid therapy as appropriate, reference dose: methylprednisolone 1~2mg/(kg?d); hydrocortisone 3~5mg/(kg?d); dexamethasone 0.2~0.5mg/(kg?d), reduce or stop as early as possible after the condition is stabilized. In individual cases, the dose can be increased if the disease progresses rapidly and is dangerous, such as giving methylprednisolone 10-20mg/kg?d (the maximum single dose does not exceed 1g) or dexamethasone 0.5-1.0mg/(kg?d) within 2-3 days.
(4) Other symptomatic treatment: hypothermia, sedation, anti-stunning.
(5) Closely observe changes in condition and monitor closely.
2. Treatment of respiratory and circulatory failure
(l) Keep the airway open and administer oxygen.
(2) Ensure two intravenous channels are open, monitor respiration, heart rate, blood pressure and blood oxygen saturation.
(3) In case of respiratory dysfunction, use positive pressure mechanical ventilation with timely tracheal intubation. It is recommended that the initial adjustment parameters of the ventilator: inhalation oxygen concentration 80%-100%, PIP 20-30cmH2O, PEEP 4-8cmH2O, f20-40 times/min, tidal volume about 6-8ml/kg. Adjust the ventilator parameters at any time according to the blood gas and X-ray chest film results.
(4) Limit fluid intake while maintaining stable blood pressure (adjust fluid volume according to central venous pressure measurement if available).
(5) Elevate head and shoulders 15-30 degrees and maintain neutral position; leave gastric tube and urinary catheter in place.
(6) Drug application: according to the changes in blood pressure and circulation, drugs such as milrinone, dopamine and dobutamine can be used; apply diuretic drug therapy as appropriate.
(7) Protect the function of important organs and maintain the stability of the internal environment.
(8) Monitor changes in blood glucose and apply insulin in case of severe hyperglycemia.
(9) Inhibit gastric acid secretion: cimetidine, omeprazole, etc. can be applied.
(10) Effective antibiotics to prevent and control secondary lung bacterial infection.
3.Recovery period treatment
(l) Avoid secondary respiratory tract and other infections.
(2)Promote the recovery of each organ function.
(3) Functional rehabilitation therapy or combined Chinese and Western medicine treatment.
Annex 1
Hand, foot and mouth disease diagnostic criteria and treatment principles
1, hand, foot and mouth disease is caused by enterovirus rash fever acute infectious disease, its type is very many, but mainly coxsackie A16 and enterovirus 71 is the most common. Although the disease can cause infections in multiple age groups, it often causes outbreaks in infants and young children. Clinical manifestations are characterized by rash and fever, with maculopapular rash often occurring on the oral mucosa and distal parts of the hands and feet. The disease generally has a good prognosis if there is no comorbidity.
2.Diagnosis principle
The diagnosis of HFMD should be based on the epidemiological data, clinical manifestations and laboratory tests and other comprehensive analysis. Confirmation of diagnosis must be based on serological and pathogenic examination.
3.Diagnosis basis
3.1.1 Epidemiological data During the epidemic season, there is an epidemic of HFMD in local childcare institutions and the surrounding population, and the patient has a history of direct or indirect contact before the onset of the disease.
3.1.2 Mostly infants and children under 5 years old.
3.1.3 Typical maculopapular and herpes-like damage on the skin and mucous membranes of the hands, feet and mouth, with katydid symptoms.
3.2 Clinical manifestations
3.2.1 Typical cases
The incubation period is usually 2-7 days, there are no obvious prodromal symptoms, and most patients have a sudden onset. About half of the patients have fever 1-2 days before or at the same time of onset, mostly around 38℃, lasting for 2-3 days, and a few patients for more than 3-4 days. Fever is almost always present with central nervous system comorbidities and lasts for a long time. Some patients initially have mild upper sensory symptoms, such as cough, runny nose, nausea, vomiting, etc. Due to painful oral mucosal ulcers, children have salivation and refusal to eat. Oral mucosal rash appears early, mainly on the tongue and cheeks, and often on the side of the lips and teeth. A maculopapular or herpetic rash appears on the distal parts of the hands and feet. The maculopapular rash changes from red to dark in about 5 days and then fades; the herpes is a round or oval flat bump with cloudy liquid inside, with the same length and diameter as the skin line, such as the size of a soybean. The papules and herpes on the distal parts of the hands and feet are generally painless and itchy, and do not leave traces after healing. In the same patient hand, foot and mouth lesions are not necessarily all present.
3.2.2 Atypical, disseminated cases
The rash is only present on one part of the patient’s body, and the macules or herpes are sparse and atypical, often difficult to distinguish from rash fever, and pathogenic and serologic tests must be performed.
3.2.3 Comorbidities Some may be combined with myocarditis, encephalitis, meningitis, chorioretinitis, pulmonary edema, etc., but aseptic encephalitis and myocarditis are the most common.
3.3 Laboratory tests
3.3.1 The total cell count of blood examination is usually normal or high, with higher lymphocytes and lower neutrophils in classification.
3.3.2 In the presence of central nervous system complications, the cerebrospinal fluid cell count may increase and protein may be elevated.
3.3.3 Associated viruses are isolated or detected from stool and throat gargle after the onset of disease.
3.3.4 Associated viruses are isolated or detected from cerebrospinal fluid or herpes fluid.
3.3.5 Detection of IgM antibodies to the associated virus from early serum.
3.3.6 There is a ≥ 4-fold increase in serum neutralizing antibodies in the recovery phase compared to the acute phase.
3.4 Diagnosis and differential diagnosis
3.4.1 The main diagnostic basis of the disease: it occurs in summer and autumn; children are the main target, often occurring in places where infants and children gather, and is epidemic; clinical manifestations of fever, followed by maculopapular rash and herpes-like damage on the oral mucosa and hands and feet; short course of the disease and good prognosis.
3.4.2 Where 3.2.1 typical cases must add any of 3.3.3 to 3.3.6. Then the disease can be diagnosed.
3.4.3 Any atypical case of 3.2.2 must add any of 3.3.4 to 3.3.6, or add 3.3.3 and 3.3.6 will also diagnose the disease.
3.4.4 The disease should be differentiated from FMD herpetic stomatitis, herpetic pharyngitis, rubella, chickenpox, etc.
4.Treatment principles
In terms of treatment, if there are no complications, the prognosis of this disease is generally good, and it will be cured within a week. The treatment principle is mainly symptomatic treatment. Can take antiviral drugs and detoxification herbs and vitamin B, C, etc.. Patients with comorbidities can be injected with propyl globulin. During the illness, the care of the child should be strengthened and oral hygiene should be done. Before and after eating, saline or warm water can be used to rinse the mouth, and non-irritating food such as liquid and semi-liquid is appropriate. Hand, foot and mouth disease can be combined with myocarditis, encephalitis, meningitis, chorioretinitis, etc., so we should strengthen the observation and not take it lightly.
5.Prevention principle
There is no specific prevention method for this disease so far. Strengthen monitoring, improve the sensitivity of monitoring is the key to control the epidemic of the disease. All places should do a good job in reporting the epidemic, and child care units should do a good job in morning inspection, timely detection of patients, collection of specimens, clear pathogenic diagnosis, and good disinfection of patients’ feces and their utensils to prevent the spread of the disease. During the epidemic period, parents should let their children go to crowded public places as little as possible to reduce the chance of infection. Hospitals should strengthen prevention by setting up special consultation rooms to prevent cross-infection. In areas where HFMD is endemic with severe comorbidities, infants and children who are in close contact with patients may be given intramuscular injections of propylene glycol.