erythema contagiosum
Introduction
Introduction to infectious erythema Erythemainfectiosum often occurs collectively in children. Some scholars believe that the disease is a viral infection, but the virus has not been isolated. It may also be an enterovirus. It is more common in the spring and autumn, and may be transmitted through the respiratory tract, causing epidemics in families, kindergartens, and schools. Occurs in children 2 to 10 years old, more common in spring and summer, the incubation period is 5 to 15 days. Often sudden onset, generally no systemic symptoms, sometimes low fever, sore throat, conjunctiva and mild congestion of the pharynx. basic knowledge Probability ratio: Susceptible people: no special people Mode of infection: droplet spread Complications: abortion
Cause
Infectious erythema
Because this disease often occurs collectively in children, some scholars believe that the disease is a viral infection, but the virus has not been isolated, it may also be an enterovirus.
Cause (65%):
Infectious diseases caused by viruses, the pathogen is parvovirus B19, active placenta transmission can occur when the virus is first infected. B19 virus is also considered to be the primary cause of chronic anemia. For a long time, it is considered to be a disease. Viral infection, but failed to obtain laboratory evidence, until 1983, Andersorl and other samples from 33 patients with infectious erythema detected the IgM and IgG antibodies of parvovirus (parvirus B19; PVB19), so this is considered The virus is the cause of infectious erythema. Later, Plummer et al detected PVDNA in the rash of patients with infectious erythema, and they also found that some family members and their school contacts did not show symptoms, but they all had Anti-PV IgM and IgG antibodies are elevated. The authors believe that PVB19 can cause many clinical manifestations, including no clinical symptoms to typical rashes. Some studies have found that pregnant women infected with PVB19 can cause miscarriage, stillbirth and fetal edema.
Pathogenesis (30%):
A vesicular pustular rash occurs, leading to anemia, aplastic crisis and chronic myelogenous failure, which may be caused by the invasion of the myeloid progenitor cells by the virus.
Prevention
Infectious erythema prevention
Most children only need to pay attention to rest, eat digestible food, drink plenty of water, if there is fever, oral antipyretics, if there are other symptoms can be given symptomatic treatment, skin lesions can be external calamine lotion to relieve itching .
The vaccines that have been developed have been tested in animals and are expected to be used for prevention in the future.
Pay attention to skin hygiene, strengthen physical exercise and increase skin's resistance.
Complication
Contagious erythema complications Complications
Sometimes infectious erythema can aggravate the condition of children with blood diseases. If pregnant women are infected with this disease, it may lead to miscarriage. These are complications of infectious erythema.
Symptom
Symptoms of infectious erythema common symptoms scaly papules acute disease erythema after ear
According to the erythema with clear butterfly edema on the face, it is epidemic, and the systemic symptoms are mild. Children who are common in spring can be diagnosed.
The incubation period is 5 to 14 days. Most of the patients are children aged 4 to 12 years old. They often have a rash and no systemic symptoms. Only a few patients have mild fever, sometimes sore throat, vomiting, conjunctival and pharyngeal congestion. The rash first appears on the cheek. Department, edematous butterfly erythema, clear boundary, no scales on it, local temperature increase, occasionally itchy and burning sensation, rash does not occur around the lips, after 1 to 2 days, symmetry in the trunk, buttocks and limbs Sexual borders are clear lace-like or reticular maculopapular rash, which is the characteristic of this disease. After 4 to 5 days, the erythema subsides from the cheeks and trunk. The rash disappears in the same order as the rash, and the rash does not desquamate and sometimes recurs. Common in spring, the course of disease is about 10 days, and the prognosis is good.
According to the special rash, there is butterfly-shaped edema flaky erythema on the cheek, the systemic symptoms are mild, epidemic, and the general condition is good. Infectious erythema, vascular purpura and other diseases are popular in some areas and have contact with patients. Can be used as a reference for diagnosis, clinical fever, especially in patients with rash should consider the possibility of this virus infection, patients with hemolytic anemia should consider the possibility of aplastic anemia, the diagnosis must be carried out pathogens And immunological examination, as well as laboratory specific examination, is not difficult to diagnose, but the clinical aspect is sometimes very similar to scarlet fever, the latter is generally heavier, acute disease, high fever, rash is diffuse, strawberry tongue, throat Cultured as a hemolytic streptococcus, helps identify.
Examine
Infectious erythema examination
In the acute phase, virus particles can be seen by electron microscopy, specific IgM antibodies in serum can be detected in the acute phase or early recovery, and specific viral DNA can be detected in serum and throat secretions.
Blood test
Peripheral blood leukocytes can be slightly reduced or normal, and hemoglobin and platelets can be reduced in people with aplastic anemia.
2.B19 DNA test
The PCR method can detect DNA from patient serum, CSF and diseased tissues, and is a diagnostic method.
3. Immunological examination
The B19 antigen in serum can be detected by radioimmunoassay or ELISA, and more IgM antibodies for B19 can be detected. The disease can reach a peak at 1 week, and it will decrease after 2 months, so there is a diagnosis of current infection. Value, IgG antibodies appear later, lasting for a long time, and have a protective effect.
Pathological changes: epidermal cell edema, dermal papillary vasodilation, endothelial cell swelling, tissue cell infiltration around blood vessels, hair follicles and sweat glands, but for chronic inflammation changes, no diagnostic value.
Diagnosis
Diagnosis and diagnosis of infectious erythema
Differential diagnosis
(1) Scarlet fever
The disease is acutely ill, clinical manifestations of sore throat, high fever, rash is diffuse erythema, pale circles around the mouth, grass plum tongue and post-peeling signs. Pascal's sign: positive.
(2) Rubella
The symptoms of upper respiratory tract catarrh, obvious fever, measles-like rash, swollen lymph nodes behind the ear and after the pillow.
(3) Measles
High fever, upper respiratory tract catarrh, obvious rash, maculopapular rash, normal skin between rashes. The early buccal mucosa is visible in the Koplik plaque.
