Acute infectious epiglottitis is an acute nonspecific inflammation of the supraglottic laryngeal mucosa mainly involving the epiglottis, which was observed by Woo (1994) using fiberoptic vocal microscopy. It can occur in both adults and children, and is more common in men than women, with a male to female ratio of about 2 to 7:1.
Causes
1. Bacterial or viral infection
The most common cause is Haemophilus influenzae type B. Takala (1994) and Alho (1995) showed that the positive blood culture rate is 80% to 90% in children and 16% to 70% in adults. Reduced body resistance, laryngeal trauma, old and weak people are susceptible to bacterial infection and disease. Other common pathogenic bacteria include Staphylococcus aureus, Streptococcus, S. pneumoniae, Neisseria catarrhalis, Corynebacterium diphtheriae, etc. They can also be mixed with viruses, such as respiratory syncytial virus, rhinovirus and influenza A virus. A variety of pathogenic bacteria can be inhaled from the respiratory tract, can also be infected by bloodstream, or spread by neighboring organs.
2.Trauma, foreign body, irritating food, harmful gas, radiation damage, etc. can cause inflammatory lesions of the supraglottic mucosa.
3.Proliferation of neighboring lesions
Such as acute tonsillitis, pharyngitis, stomatitis, rhinitis, etc. spread and invade the supraglottis mucosa. It can also be secondary to acute infectious diseases.
Pathology
The submucosal connective tissue in the supraglottic region such as the lingual and lateral margins of the epiglottis, the aryepiglottic fold, and the subglottic region is lax, and inflammation often starts here, causing a high degree of congestion and swelling of the epiglottis, which can sometimes thicken to 6-10 times normal. The inflammation gradually extends to the arytenoid cartilage or ventricular zone, and in severe cases, it can spread to the aryteno-epiglottic fold, adjacent tissues on the pharyngeal side and soft tissues in front of the neck. Because of the tight submucosal layer of the vocal cord mucosa attached to the vocal cord, submucosal edema is often bounded by the vocal cord, and inflammation in the supraglottic region generally does not extend to the subglottis.
The pathological histological changes can be divided into 3 types.
1. Acute khat type
The mucosa is diffusely congested and edematous, with mononuclear and polymorphonuclear cell infiltration, and the mucosa of the lingual surface of the epiglottis is more relaxed and swollen more obviously, and can thicken to 6-10 times the normal.
2.Acute edema type
The epiglottis is significantly swollen like a round ball, with interstitial edema and increased inflammatory cell infiltration, and an abscess can be formed locally.
3.Acute ulcer type
Rarely, the disease develops rapidly and seriously, and the germs often invade the submucosa and glandular tissue, and septicemia and ulceration may occur. If the blood vessel wall is eroded, it can cause erosion and bleeding.
Clinical manifestations
1.Onset
The onset of the disease is rapid, often occurring suddenly at night, and the history of the disease rarely exceeds 6-12 h. Most patients fall asleep normally and wake up in the middle of the night with sudden pain in the throat or difficulty in breathing.
2.Chill and fever
Adults may have chills and fever before the onset of the disease, with most patients having a body temperature of 37.5°C to 39.5°C and a few up to 40°C or more. The patient is irritable, depressed, and weak. The degree of fever is related to the type of causative organism, such as a mixed infection, the body temperature is mostly higher. Young children choke and vomit when drinking water.
3.Sore throat
It is the main symptom, and the pain increases when swallowing.
4.Difficulty in swallowing
Swallowing action or food mass directly stimulates the epiglottis, resulting in pain in the throat, salivation and refusal to eat. The pain can be radiated to the lower jaw, neck, ear or back. If the mucosa at the epiglottis and arytenoid cartilage is extremely swollen, dysphagia may occur.
5.Difficulty in breathing
Due to the swelling of the mucosa of the epiglottis, the mucosa of the arytenoid cartilage, the arytenoid fold and the posterior wall of the pharynx are also edematous, causing the entrance to the larynx to shrink significantly and obstructing the vocal cords, resulting in inspiratory dyspnea. If the condition continues to deteriorate, asphyxia may occur suddenly within 4-6 hours due to the obstruction of mucous phlegm in the larynx. Although the patient has dyspnea, but the pronunciation is mostly normal, some voices are low and slurred, and hoarseness rarely occurs.
6. Fainting and shock
Patients may appear fainting or shock within a short period of time, manifested as dyspnea, mental depression, weakness, cold limbs, pale face, fast and thin pulse, and decreased blood pressure. Therefore, we should closely observe and prepare for resuscitation, and once the above situation occurs, anti-shock treatment should be given immediately.
7.Cervical lymph node enlargement
Swollen and painful deep cervical lymph nodes on one or both sides, sometimes radiating to the ear and back.