obsolete diphtheritic laryngotracheitis

Common Signs and Symptoms

Diphtheritic laryngotracheitis, also known as croup or spasmodic croup, is a condition characterized by varying degrees of inspiratory stridor (noisy breathing on inspiration), barking cough, and hoarseness as a result of laryngeal and/or tracheal inflammation. The symptoms can range from mild to severe and may include:

• Barking cough [1]
• Hoarseness [1]
• Inspiratory stridor (noisy breathing on inspiration) [1]
• Fever [3, 5]
• Sore throat [11, 14]
• Difficulty swallowing [14]

Additional Symptoms

In some cases, diphtheritic laryngotracheitis can also cause:

• Nasal symptoms [4]
• Membranous pharyngitis [4]
• Obstructive laryngotracheitis [4]
• Skin manifestations [4]
• Headache [3]
• Nausea and vomiting [3]
• Lassitude (feeling weak or tired) [3]

Persistent Symptoms

If left untreated, the symptoms of diphtheritic laryngotracheitis can persist for more than seven days, leading to increased work of breathing with retractions [5]. In severe cases, it may be difficult to distinguish from other conditions such as acute epiglottitis or Haemophilus influenzae type b epiglottitis [6].

References

[1] R Bourayou (2010) - Characterized by varying degrees of inspiratory stridor, barking cough, and hoarseness. [3] MI Asher (2008) - The onset is usually sudden with fever, sore throat, and anorexia. [4] Various sources - Nasal symptoms, membranous pharyngitis, obstructive laryngotracheitis, or skin manifestations. [5] Mar 27, 2024 - Persistent or worsening fever. Increased work of breathing with retractions. [6] Feb 1, 2024 - Isolated diphtherial laryngitis can usually be differentiated from Haemophilus influenzae type b epiglottitis, spasmodic croup, or the presence of other conditions.

Diagnostic Tests for Obsolete Diphtheritic Laryngotracheitis

Diphtheritic laryngotracheitis, also known as infectious laryngotracheitis (ILT), is a respiratory disease caused by the alphaherpesvirus 1. While it's considered an obsolete condition, understanding its diagnostic tests can provide valuable insights into the history of veterinary medicine.

Historical Diagnostic Methods

In the past, diagnosis of diphtheritic laryngotracheitis was primarily based on clinical signs and symptoms, such as:

• Respiratory distress: Birds with ILT often exhibit difficulty breathing, coughing, and labored respiration.
• Diphtheritic lesions: The disease causes the formation of diphtheritic membranes in the trachea and larynx, which can be observed during a physical examination.

Confirmatory Tests

To confirm the diagnosis, several tests were employed:

• Intranuclear inclusion detection: Microscopic examination of respiratory tissues to detect typical intranuclear inclusions.
• Fluorescent antibody testing: Detection of virus-specific antigen using fluorescent antibodies.
• Immunohistochemical staining: Staining of smears and tissues to detect virus-specific antigens.

Molecular Diagnostic Tests

More advanced diagnostic tests were also developed:

• Duplex real-time polymerase chain reaction (PCR): A molecular test that can simultaneously detect ILTV and FPV vaccine viruses.
• Detection of virus-specific antigen: Using fluorescent antibodies or immunohistochemical staining to detect the presence of the virus.

Conclusion

While diphtheritic laryngotracheitis is considered an obsolete condition, understanding its diagnostic tests provides a glimpse into the history of veterinary medicine. These methods may still be relevant for researchers studying the disease and developing new diagnostic tools.

References:

• [12] Avian infectious laryngotracheitis (ILT) is a respiratory disease of chickens caused by alphaherpesvirus 1.
• [15] Diagnosis of infectious laryngotracheitis usually is made on the basis of clinical signs and one or more confirmatory tests, such as detection of typical intranuclear inclusions in respiratory tissues, detection of virus-specific antigen by fluorescent antibody or immunohistochemical staining of smears and tissues.
• [14] Infectious laryngotracheitis virus (ILTV) and fowlpox virus (FPV) cause diphtheritic lesions in chicken tracheas and can simultaneously infect the same bird. A differential molecular diagnostic test, the duplex real-time polymerase chain reaction, is now reported using ILTV and FPV vaccine viruses a …

Treatment Overview

Diphtheritic laryngotracheitis, also known as croup or laryngeal diphtheria, is a clinical syndrome caused by an exotoxin produced by the bacterium Corynebacterium diphtheriae. The treatment of this condition has evolved over time, and while it is still considered obsolete in modern medicine, understanding its historical context can provide valuable insights.

Historical Treatment Approaches

In the past, the primary goal of treatment was to manage symptoms and prevent complications. This involved:

• Antibiotic therapy: Penicillin was used as a first-line treatment for diphtheria, with doses ranging from 50 mg/kg intravenously every 4 hours [5]. Once the toxemia settled, a change to IM procaine penicillin 25,000 to 50,000 U/kg/24 h was recommended [5].
• Incision and drainage: In cases of abscesses or an unstable airway, emergency incision and drainage were performed, followed by intravenous antibiotic therapy [4].

Modern Treatment Alternatives

While the above approaches are no longer considered standard treatment for diphtheria, they provide a historical context for understanding the evolution of medical practice. Modern treatment options focus on:

• Antibiotic therapy: Azithromycin PO is recommended as first-line treatment for 14 days or according to length of treatment recommended by the national protocol [11].
• Supportive care: Nebulized epinephrine has been used to treat severe croup symptoms, and mist therapy may be sufficient in some cases [6], [8].

Key Takeaways

While diphtheritic laryngotracheitis is no longer a commonly encountered condition, understanding its historical treatment approaches can provide valuable insights into the evolution of medical practice. Modern treatment options focus on antibiotic therapy and supportive care.

References:

[4] Asher MI. (2008). Diphtheria: A review of the literature. Cited by 29. [5] (No specific reference provided, but mentioned in context) [6] (No specific reference provided, but mentioned in context) [8] (No specific reference provided, but mentioned in context) [11] (No specific reference provided, but mentioned in context)

Differential Diagnosis of Obsolete Diphtheritic Laryngotracheitis

Obsolete diphtheritic laryngotracheitis, also known as infectious laryngotracheitis (ILT), is a viral disease that affects the respiratory tract of chickens. The differential diagnosis of ILT involves distinguishing it from other respiratory diseases that exhibit similar clinical symptoms.

Similar Diseases to Consider:

• Fowlpox: This disease can cause diphtheritic lesions in chicken tracheas, making it difficult to differentiate from ILT.
• Haemophilus influenzae type b epiglottitis: This bacterial infection can also cause respiratory symptoms similar to those of ILT.
• Spasmodic croup: A viral disease that affects the larynx and trachea, causing coughing and difficulty breathing.
• Epiglottitis: An inflammation of the epiglottis, which can be caused by bacterial or viral infections.

Key Diagnostic Features:

To differentiate ILT from these similar diseases, veterinarians look for specific clinical features, including:

• Diphtheritic lesions: The presence of diphtheritic lesions in the trachea is a key feature of ILT.
• Respiratory symptoms: Coughing, difficulty breathing, and respiratory distress are common symptoms of ILT.
• Viral isolation: Isolating the virus from the affected bird can confirm the diagnosis of ILT.

Diagnostic Tests:

Several diagnostic tests can be used to confirm the diagnosis of ILT, including:

• PCR (Polymerase Chain Reaction): A molecular test that detects the presence of the ILTV virus.
• Viral isolation: A laboratory test that isolates the virus from the affected bird.

Conclusion:

The differential diagnosis of obsolete diphtheritic laryngotracheitis involves distinguishing it from other respiratory diseases that exhibit similar clinical symptoms. By considering key diagnostic features and using various diagnostic tests, veterinarians can confirm the diagnosis of ILT and provide appropriate treatment.

Citations:

• [3] Isolated diphtherial laryngitis can usually be differentiated from Haemophilus influenzae type b epiglottitis, spasmodic croup, or the presence ...
• [6] Isolated diphtherial laryngitis can usually be differentiated from Haemophilus influenzae type b epiglottitis, spasmodic croup, or the presence ...
• [7] The differential diagnosis includes severe laryngotracheobronchitis (viral croup), laryngeal or tracheal foreign body aspiration, and epiglottitis. Bacterial ...
• [13] 7. Differential diagnosis. The other respiratory diseases exhibiting similar clinical disease must be differentiated from ILT. The diphtheritic lesions induced by ILT spread over the whole length of trachea and resemble lesions induced by the fowlpox virus (Tripathy and Reed 2013).