Acute epiglottitis, also known as supraglottitis or preglottic isthmus, is a specific acute inflammatory lesion that mainly involves the epiglottis and its surrounding tissues (including epiglottic valley and aryepiglottic folds) in the supraglottic region of the larynx, characterized by a high degree of edema of the epiglottis. Acute epiglottitis is one of the most serious laryngological emergencies and can occur in both children and adults, mainly manifesting as systemic toxic symptoms, swallowing and breathing difficulties. Acute epiglottitis progresses rapidly, and most patients can be cured with timely treatment, while a few patients are in dangerous condition and suffocate quickly, with high mortality.
1 . Causes
The main causes include infection, trauma, metabolic reactions, etc. Infection is the most common cause of this disease. In the past, the most common causative agent was Haemophilus influenzae type B. After the development of vaccines against this pathogen in Europe and the United States, the number of acute epiglottitis caused by Haemophilus influenzae type B has gradually decreased. Other pathogens include Haemophilus parainfluenzae, Group A Streptococcus, Streptococcus pneumoniae, Staphylococcus aureus, Mycobacterium, Streptococcus, Enterobacter cloacae, Escherichia coli, Clostridium necrophorum, Klebsiella pneumoniae, Neisseria meningitidis, and others. Viruses can also cause the disease, such as varicella-zoster virus and herpes simplex virus type I. In immunocompromised patients, there can also be fungal infections such as Candida and Aspergillus.
Trauma: Thermal injury (hot drinks, steam inhalation, etc.), mechanical injury (foreign body trauma, medical device injury, etc.), chemical injury (irritating harmful gases, irritating foods, etc.), and radiation injury can cause inflammatory lesions of the mucosa of the epiglottis, followed by edema.
Allergic reactions: Reactions to certain allergens occur due to diet, drugs or insect bites, etc. Systemic allergic reactions can cause a high degree of edema in the mucosa of the epiglottis area and the aryepiglottic folds. Proximity of organs
Acute inflammation: Acute inflammation of surrounding organs such as acute tonsillitis, pharyngitis, funditis, rhinitis, etc. can spread and invade the mucosa of the epiglottis, causing edema. It can also be secondary to acute infectious diseases.
2.Pathogenesis
Respiratory infections, trauma, and allergic reactions may cause inflammatory reactions in the surrounding tissues of the larynx, which may then invade the epiglottis. Since the venous blood flow of the epiglottis passes through the root of the epiglottis, if the root of the epiglottis is compressed by inflammatory infiltration, the venous flow will be blocked and the epiglottis will rapidly develop severe edema, which will not subside easily. At the same time, the inflammation of the tissue around the epiglottis can push back the epiglottis, and with the further development of inflammation and edema, it is possible that the swollen epiglottis will completely block the airway, causing asphyxia and death.
3.Pathophysiology
The mucosa of the lingual surface of the epiglottis and its lateral edge of the aryepiglottic folds is loose. Acute epiglottitis is often characterized by congestion and edema on the lingual surface of the epiglottis, which can spread to the aryepiglottic folds, aryepiglottic cartilage or epiglottic valley, but rarely invades the vocal cords and subglottic area. The epiglottis mucosa is highly congested and swollen, and the edematous epiglottis is often 6 to 7 times thicker than normal. In cases of intense inflammation, abscesses can form locally in the later stages of the disease.
Pathological histological changes can be divided into three types as follows.
Acute cicatricial type: Acute cicatricial inflammation of the epiglottis mucosa, manifested by diffuse congestion and edema of the epiglottis mucosa with mononuclear and polymorphonuclear cell infiltration. Since the submucosal tissue of the lingual surface of the epiglottis is more relaxed, the swelling of the lingual surface of the epiglottis is obvious.
Acute edema type: If metaplastic inflammation occurs in the epiglottis, the mucosal lesion is mainly edema of interstitial tissue, inflammatory cell infiltration increases, and the epiglottis is enlarged and spherical. At this time, it is easy to cause laryngeal obstruction.
Acute ulcerative type: less common, but the disease develops rapidly and seriously. The lesions often invade the submucosa and glandular tissue, local septic and ulcers can occur, when the lesions invade the vascular wall can cause vascular wall erosion and bleeding.
4.Epidemiology of clinical manifestations
Both adults and children can develop the disease. In China, it is mostly seen in adults, but the incidence in children is higher abroad. In the past, acute epiglottitis was more common in children in Europe and the United States, but since the popularization of Haemophilus influenzae type B vaccine, children with this disease have become rare. In recent years, there is an increasing trend of adult patients. In children, the disease usually occurs between the ages of 2 and 4 years, and in adults, the average age of onset is about 45 years. Males are about three times more likely to develop the disease than females. Acute epiglottitis can occur throughout the year, but is more common in winter and spring.
Symptoms of the disease
Acute epiglottitis has a rapid onset and progresses very rapidly, with the main symptoms being severe laryngeal pain, dysphagia and dyspnea.
(1) Systemic symptoms
In mild cases, the systemic symptoms are not obvious, but in severe cases, there are fever and chills, with body temperature between 38 and 39℃, and a few can reach above 40℃. Acute disease appearance can be seen on physical examination. In children and elderly patients, the systemic symptoms are more obvious and the disease progresses rapidly. In children, failure can occur rapidly, manifested as mental depression, physical weakness, cold limbs, pale face, rapid and thin pulse, decreased blood pressure, and even fainting and shock.
(2) Local symptoms
Sore throat: Except for infants who cannot complain of sore throat, most patients have severe and progressively increasing sore throat, accompanied by obvious painful swallowing. Sometimes the twisting of the neck can cause severe pain in the throat.
Difficulty in swallowing: Due to the severe swallowing pain and swelling of the epiglottis, the swallowing function is seriously affected and even saliva is difficult to swallow. In severe cases, the patient often chokes on water and opens the mouth to salivate. In mild cases, the patient feels a foreign body in the throat. Occasionally, difficulty in opening the mouth is seen. Slurred speech: Due to the swelling of the epiglottis, the patient has a feeling of throat obstruction and slurred speech. The vocal cords are often not involved and hoarseness is rarely present.
(3) Dyspnea
When the epiglottis is highly swollen, the vocal folds become small and the mucous phlegm is obstructed, inspiratory dyspnea appears, accompanied by inspiratory laryngeal tinnitus; in severe cases, dyspnea appears early and progresses rapidly, and can cause asphyxia within a few hours. Dyspnea can be manifested in a special position when breathing, usually in a forward leaning position, and in children it can be manifested in a sniffing position, i.e., the body is leaning forward, with the head and nose stretched forward and upward, as if smelling. In addition, the patient is more agitated and cannot be quiet, the respiratory rhythm becomes shallow and fast, and the triple concave sign may appear, i.e. the suprasternal fossa, supraclavicular fossa and intercostal space are obviously depressed downward during breathing.
(4) Specialist examination
If you suspect acute epiglottitis, you should go to the otolaryngology department of the hospital promptly. The doctor can make a judgment through oropharyngeal examination and indirect laryngoscopy.
Indirect laryngoscopy: Early in the course of the disease, the epiglottis is swollen and thickened, pale white or cherry red, especially on the lingual surface, and in severe cases, the epiglottis can be enlarged and spherical. In the later stage, there can be limited abscess formation on the lingual surface of the epiglottis, which can be seen as a localized elevation with yellow pus spots, pus heads, or small fistulas with overflowing pus. Occasionally, ulceration may be present. When inflammation involves the aryepiglottis and the aryepiglottic mucosa, the mucosa is swollen and congested, and the vocal and subvocal areas are difficult to see because the aryepiglottis cannot be raised. Inflammation involving the laryngeal surface of the epiglottis is rare, and once involved, the dyspnea is more serious.
5, auxiliary examination laryngoscopy
Direct laryngoscopy, fiberoptic laryngoscopy, etc., such as indirect laryngoscopy observation of the epiglottis is not satisfactory, such tests are feasible to help the diagnosis.
Laboratory tests
Routine blood tests: such as increased white blood cells, suggesting infection or inflammatory manifestations. Arterial blood gas analysis: signs of hypoxia such as decreased oxygen saturation. Blood culture: can indicate the type of pathogenic bacteria causing the infection. Immunological examination: antibodies to specific pathogens can be detected, etc.
Imaging examinations
Lateral plain radiograph of the larynx: normal epiglottis is a thin, curved sheet of soft tissue shadow, separated from the root of the tongue by the air in the epiglottic valley. In acute epiglottitis, the swelling of the epiglottis increases, and the shadow of the laryngopharyngeal airway shrinks and is clearly defined, in addition, the shadow of the epiglottic valley may disappear. CT of the neck: This test carries a risk of delay. It is mainly used to observe abscess formation and to exclude other diseases such as deep neck abscess, foreign body in the throat, etc. CT shows thickening of the epiglottis and its surrounding tissues and loss of the anterior epiglottic space. MRI of the neck: This test also carries the risk of delay. It is mainly used to exclude other diseases and confirm related complications.
6.Diagnosis
In patients complaining of acute sore throat, if there are no obvious changes in the mucosa of the oropharynx and tonsils on examination, the possibility of acute epiglottitis should be considered, and indirect laryngoscopy can mostly confirm the diagnosis. Laboratory tests and imaging examinations are not necessary for diagnosis, and should be omitted if the diagnosis is clear, so as not to delay the treatment and rescue time.
7.Differential diagnosis
Simple laryngeal edema
The onset is rapid, with rapid onset of laryngeal tinnitus, hoarseness, dyspnea, and even asphyxia. There is often a foreign body sensation in the larynx and difficulty in swallowing. On examination, the laryngeal mucosa is diffusely edematous, pale and shiny, and the aryepiglottic folds are swollen in the shape of salami, and the epiglottis may also be swollen.
Laryngeal diphtheria
The onset of laryngeal diphtheria is slow, with low fever, hoarseness, no dysphagia, slow development of dyspnea, and severe cough. On examination, there is a pseudomembrane in the throat that cannot be easily swabbed away. The pathogen is Corynebacterium diphtheriae.
Acute laryngotracheobronchitis
The onset of the disease is usually acute, with high fever, hoarseness, no dysphagia, and rapid development of dyspnea with paroxysmal cough. On examination, the subglottic mucosa is congested and swollen. The pathogen is often Staphylococcus aureus or Streptococcus.
Foreign body in the larynx
There is a history of accidental ingestion of foreign bodies, and most foreign bodies can be found on physical examination.
8.Complications Local complications
Epiglottis abscess, cervical cellulitis, epiglottis chondrogenesis, etc.
Distant complications
Vocal cord granuloma, cervical lymphadenitis, necrotizing fasciitis, meningitis, pneumonia, pulmonary edema, abscess chest, pneumothorax, mediastinal emphysema, pericarditis, septic arthritis, etc. Systemic complications
Infectious toxic shock: common in pediatric patients.
Death by respiratory distress and asphyxia.
9.Disease treatment
Acute epiglottitis is an acute and serious disease in laryngology. Patients with acute severe laryngeal pain or any manifestation suggestive of respiratory distress and suspected acute epiglottitis should seek immediate medical attention. Patients with acute epiglottitis with an onset of less than 24 hours require hospitalization, close observation of respiratory changes, and preparation for the establishment of an artificial airway while medication is administered.
The principles of treatment include keeping the airway open and controlling the infection.
10.Drug treatment
Glucocorticoid: hormone has the effect of treating and preventing the edema of epiglottis and aryepiglottic folds, and also has non-specific anti-inflammatory, anti-allergic and anti-shock effects. Early use in combination with antibiotics.
Antibiotics: Early selection of broad-spectrum antibiotics that can target Haemophilus influenzae type B infection by intravenous drip, switching to oral antibiotics after stabilization.
Local treatment: Local administration of antibiotics plus hormonal laryngeal nebulizer inhalation treatment can reduce local edema and promote inflammation subsidence. Surgical treatment
Incision and drainage: If there is local abscess formation, incision and drainage should be performed, which is conducive to rapid infection control and can reduce the amount of antibiotic drugs, reduce toxemia and shorten the course of the disease. If the foci of infection are not yet limited, incision should not be performed prematurely to avoid the spread of inflammation.
Establishment of artificial airway: including transoral or transnasal tracheal intubation, cricothyrotomy, tracheotomy, etc. Practical methods should be selected according to the condition, equipment conditions and technical ability of the medical staff.
Supportive treatment
Oxygen therapy should be administered to supplement inadequate ventilation and improve general condition.
If you have difficulty in eating, give intravenous rehydration and other supportive treatment.
11.Disease prevention prevention methods
To prevent the occurrence of acute epiglottitis, exercise should be strengthened to enhance the body’s resistance. For the acute inflammation of the adjacent organs of the epiglottis, timely treatment should be given to prevent the spread of infection. To maintain oral hygiene, quit smoking and alcohol, and eat less spicy and stimulating food. Patients with diabetes should pay attention to blood sugar control.
Preventive medicine
In children, Haemophilus influenzae type B vaccine can be administered to prevent infection by this pathogen. In adults, the injection is not recommended, except for special populations with low immunity, such as sickle cell anemia, post-splenectomy, tumors and other conditions affecting immune function.
12.Disease care condition observation
Observe the effect of oxygen and application of antibiotics and hormone therapy, observe the patient’s respiratory-related manifestations and general condition.
Diet care
In acute epiglottitis, pharyngeal pain is obvious, especially aggravated when swallowing, and patients often refuse to eat, so the importance of eating should be explained to patients. The patient should be told the importance of eating. The diet should be light, and a nutritious full- or semi-fluid diet should be chosen, with no coarse, hard or irritating foods.
Oral care
Due to the influence of inflammation, the mechanical self-cleaning effect of the oral cavity is impaired, inflammatory secretions are excreted into the oral cavity, necrotic epithelium is shed, food residues are retained and the patient is reluctant to eat due to many factors such as pain in the pharynx, which aggravates oral uncleanliness. Mouthwash can be used to gargle, which can not only reduce oral odor, but also promote wound healing.
Psychological care
Most of the patients have tension and fear due to respiratory distress and suffocation, so they should increase their sense of security and reduce their psychological pressure.