What is the Cause of Hepatocutaneous Syndrome?

Hepatocutaneous syndrome is primarily caused by severe chronic liver disease but there can be a variety of underlying factors that lead to its development. It's most commonly observed in dogs, though occasionally cats can be affected.

Underlying Causes

• Chronic Liver Disease or Vacuolar Hepatopathy: This is the leading cause in animals, marked by severe liver cell damage characterized by glycogen-like buildup in liver cells. This kind of liver impairment disrupts normal body functions, which then affects the skin.
• Pancreatic or Neuroendocrine Tumors (Glucagonoma): These are less common but significant causes. Such tumors secrete excessive glucagon, impacting amino acid metabolism and contributing to skin lesions.
• Diabetes Mellitus: Often associated with this syndrome, particularly when liver dysfunction is present.
• Endogenous Steroid Excess or Chronic Medications: Long-term use of drugs like phenobarbital, or conditions like Cushing’s disease, can lead to liver injury, predisposing animals to this condition.

Pathophysiology: Why Do the Skin and Liver Both Get Affected?

The key issue here is a marked decrease in plasma amino acid concentrations, also known as hypoaminoacidemia. This deficiency prevents proper protein and collagen synthesis, leading to skin cell death and the distinct ulcerative lesions seen in these animals. Additional factors include:

• Excessive Amino Acid Catabolism due to liver dysfunction.
• Aminoaciduria, where amino acids are lost in urine.
• Disrupted Amino Acid Transport within tissues.
• Abnormal Zinc Metabolism may also play a role.

Examples and Clinical Insights

• In Dogs: Cases often stem from chronic liver disease, diabetes, tumors, or long-term medication use.
• In Cats: Although rare, it might occur secondary to liver disease, diabetes, tumors, or even specific viral infections.
• Lesion Management: Treatment of the underlying condition (like diabetes control or tumor removal) can result in lesion resolution, although prognosis can be guarded due to underlying liver damage.

Summary Table of Major Causes in Animals

 

Actionable Takeaways

• Diagnosis: Requires skin biopsy and liver evaluation for identifying the underlying pathology.
• If you observe symmetric crusting or ulceration on your patient’s skin, especially with lethargy or if there's known liver disease, consider hepatocutaneous syndrome. It's crucial to follow up with comprehensive tests like blood tests for amino acids, glucose, and liver enzymes.

In essence: While chronic liver disease is the most prevalent cause of hepatocutaneous syndrome, other factors such as pancreatic tumors, diabetes, and long-term medication use can contribute to its onset. The central concern is hypoaminoacidemia, which hinders skin repair, leading to its distinctive skin lesions.