Diphtheria of the larynx

Laryngeal diphtheritic croup, or laryngeal diphtheria, is observed in severe forms of diphtheria, manifested by signs of a general infectious disease.

And although diphtheritic sore throat and laryngitis are rare nowadays, thanks to vaccination with diphtheria toxoid, there are still cases of acute primary diphtheritic laryngitis, limited only to the disease of the larynx.

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Causes of Laryngeal Diphtheria

Laryngeal diphtheria occurs as a result of a descending infection nesting in the nasal cavity and nasopharynx of bacteria carriers. Less often, laryngeal diphtheria occurs after a common sore throat. Diphtheria croup occurs much more often in children under 5 years of age, especially those weakened by childhood infections, vitamin deficiency, alimentary insufficiency, etc.

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Pathological anatomy

In the debut stage of the disease, the infection causes an inflammatory reaction that is no different from a banal catarrhal inflammation. However, soon ulcers form on the mucous membrane, on the surface of which pseudomembranous films of a yellowish-green color are formed, formed from fibrin and containing a large number of diphtheria pathogens. These films are tightly fused with the mucous membrane of the larynx, especially on its back surface and vocal folds. Later they are rejected, forming as if casts from the inner surface of the larynx. In some cases, diphtheria toxin causes ulcerative-necrotic damage to the mucous membrane and underlying tissues.

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Symptoms of diphtheria of the larynx

The onset of the disease is insidious, it is often mistaken for a common cold or catarrhal pharyngitis: a slight subfebrile temperature, pale face, adynamia, reddening of the pharynx and a slight runny nose - symptoms that cannot indicate the onset of a very serious disease in its consequences in the debut stage. However, soon with the appearance of diphtheria films, the general condition of the patient sharply worsens, the body temperature rises to 38-39 ° C, the voice changes, which becomes dull, inexpressive, almost hissing, a cough appears, breathing becomes noisy, and with increasing stenosis of the larynx - and stridorous character, which indicates the onset of croup of the larynx.

In the clinical course of laryngeal diphtheria, three stages can be distinguished:

• stage of dysphonia, characterized by hoarseness of the voice, dry, initially barking cough; after 1-2 days, dysphonia ends in complete aphonia;
• dyspneic stage, the signs of which occur already in the middle of the dysphonia stage and already on the 3-4th day dominate the clinical course of the disease - noisy stridor breathing appears, attacks of laryngeal spasm with phenomena of inspiratory suffocation become more frequent; the latter is manifested by retraction on inhalation over the chest and other and supraclavicular fossae, intercostal spaces; in the general condition of the patient, signs of hypoxia predominate, the face acquires an earthy tint, the lips and nasolabial triangle are cyanotic, breathing is frequent, shallow, the pulse is frequent and thready, heart sounds are weakened and muffled, which may indicate the onset of toxic myocarditis; the child lies in bed with his head thrown back (phenomena of meningism), shows motor restlessness, a dull, wandering look; the extremities are cold, the body is covered with cold sweat;
• the terminal stage is characterized by a pronounced hypoxic toxic syndrome, manifested by damage to the vasomotor and respiratory centers; if the disease has reached this stage, then any medication or oxygen treatment does not improve the patient's condition, who eventually dies from paralysis of the bulbar centers.

Laryngoscopy at the onset of the disease reveals diffuse hyperemia and edema of the mucous membrane, which is covered with a light whitish coating, which later transforms into dirty gray or green films, as noted above, tightly fused with the underlying tissues. When attempting to remove them, ulcers and small-point hemorrhages (the "bloody dew" symptom) are revealed underneath them. These pseudomembranous deposits can spread downwards into the subglottic space and further onto the mucous membrane of the trachea. In some cases, edema of the vestibule of the larynx is revealed, which hides the picture of diphtheria of the subglottic space and trachea.

Complications of laryngeal diphtheria: bronchial pneumonia, abscess and perichondritis of the larynx, post-diphtheritic polyneuritis (paralysis of the soft palate, extraocular muscles, accommodation disorders, paralysis of the limbs).

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Diagnosis of laryngeal diphtheria

If diphtheria croup is accompanied by bacteriologically established diphtheria of the pharynx, or if the latter is followed by signs of acute laryngitis, then diagnostics do not cause any particular difficulties. However, if diphtheria of the larynx develops primarily, then the presence of diphtheria infection, especially at the initial stage, can only be assumed based on the epidemiological anamnesis, i.e. if the child was in contact with a patient with diphtheria or in an environment where diphtheria cases were observed and there are carriers of the diphtheria pathogen.

Laryngeal diphtheria is differentiated from pseudocroup, influenza laryngobronchitis and other acute infectious diseases of the larynx. Laryngeal diphtheria is also differentiated from laryngeal stridor, laryngospasm, foreign bodies in the larynx, retropharyngeal abscess, allergic edema and papillomatosis of the larynx, etc.

The final diagnosis is established only after receiving a positive bacteriological response. But even if its results are doubtful or have not yet been received, and the clinical picture indicates the possible presence of laryngeal diphtheria, specific serotherapy is immediately started.

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Treatment of laryngeal diphtheria

Treatment for suspected laryngeal diphtheria is urgent and comprehensive, and is carried out in a specialized hospital for infectious patients. It includes the following measures:

• large doses of anti-diphtheria antitoxic serum (3000 AE/kg) are prescribed both intramuscularly and subcutaneously using the modified method of A.M. Bezredka, and antihistamines (suprastin, diazolin, etc.) are used simultaneously;
• Antibiotics are prescribed in combination with hydrocortisone to prevent pneumonia, toxic pulmonary edema and secondary complications;
• cardiac and respiratory analeptics, vitamin B12 and cocarboxylase are also prescribed to prevent toxic damage to vital centers and diphtheritic polyneuritis;
• conduct intensive detoxification therapy;
• to prevent reflex spasms of the larynx, barbiturates (phenobarbital) are prescribed in small doses, often;
• inhalations and instillations into the larynx of proteolytic enzymes, hydrocortisone, alkaline-oil solutions, antibiotics, adrenaline, and ephedrine are performed;
• small children are placed in an oxygen chamber, older children are prescribed mask oxygen or carbogen therapy;
• if obstructive asphyxia occurs, direct laryngoscopy is performed with aspiration of false membranes and thickened mucus;
• If asphyxia occurs, one should not hope for improvement of breathing and postpone the production of a tracheotomy, since respiratory obstruction of the larynx can occur instantly, and then all interventions for respiratory rehabilitation may be too late.

Prevention of laryngeal diphtheria

Prevention of laryngeal diphtheria involves the following measures:

• mandatory vaccination of all children with diphtheria vaccine;
• registration of carriers of the diphtheria pathogen and preventing them from working in children's institutions;
• conducting a bacteriological examination for the diphtheria pathogen of all persons entering work in children's groups, children's and adult psychoneurological hospitals;
• carrying out final disinfection in the diphtheria outbreak, etc.

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Prognosis for laryngeal diphtheria

The prognosis for laryngeal diphtheria is serious, especially in children under 2 years of age, in whom the infection often spreads to the trachea and bronchi, causing severe forms of diphtheritic bronchopneumonia. In hypertoxic forms, even in older children and adults, the prognosis remains guarded.

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