What is Haff disease, and what are its symptoms?

Haff disease is a rare condition characterized primarily by rhabdomyolysis—a severe muscle injury disease that may lead to kidney failure—after consuming certain freshwater fish. Currently, the exact cause of Haff disease is not fully understood, but it is associated with toxins present in specific fish species. Generally, Haff disease may present symptoms such as electrolyte disturbances, kidney dysfunction, abnormal urine, nausea and vomiting, and muscle weakness. A detailed analysis is as follows:

1. Electrolyte disturbances: Haff disease can cause damage to muscle cells, leading to abnormal levels of electrolytes such as blood potassium and calcium, which may result in symptoms including rapid heartbeat and altered mental status.

2. Kidney dysfunction: Myoglobin released from rhabdomyolysis can block the renal tubules, causing acute kidney injury, which may manifest as oliguria or anuria and elevated serum creatinine and blood urea nitrogen levels.

3. Abnormal urine: Following muscle cell lysis, myoglobin enters the urine, causing the urine color to turn dark brown or resembling soy sauce.

4. Nausea and vomiting: Due to metabolic disturbances caused by rhabdomyolysis, some patients may experience nausea and vomiting during the early stages of the illness.

5. Muscle weakness: Some patients may experience muscle weakness after muscle damage, potentially limiting their ability to perform daily activities.

Treatment for Haff disease mainly involves supportive therapy, such as aggressive hydration, to prevent arrhythmias or cardiac arrest. Additionally, medications such as metoprolol tartrate tablets, propranolol hydrochloride tablets, and sodium bicarbonate tablets may be used under a physician's guidance to alleviate symptoms.