Difference Between CSS and SIADH

CSS vs SIADH

CSS is a syndrome which involves necrosis of the small and medium blood vessels, due to autoimmune vasculitis.  SIADH involves the excessive secretion of ADH or antidiuretic hormones.

CSS

CSS stands for Churg-Strauss syndrome. It is also referred to as Allergic Granulomatosis. The syndrome involves autoimmune vasculitis, affecting the small and medium vessels. Vasculitis refers to a group of disorders (heterogeneous), in which the blood vessels are destroyed by inflammation.

Vasculitis is caused primarily due to the migration of leukocytes. In CSS, autoimmune vasculitis leads to necrosis. Necrosis refers to the premature death of living cells and tissues. Necrosis is caused by external factors like toxins, infections, and trauma.

CSS mainly involves the blood vessels of the gastrointestinal system, lungs and peripheral nerves. It affects the skin, heart and kidneys as well. CSS is categorized as a rare disease, and is non-transmissible and non-inheritable.Diagnosis includes a positive result of at least 4 or more (out of 6) tests performed to identify it.

CSS has three stages. The first stage of CSS involves an onset of allergies and/or sinus symptoms (which the patient previously did not have), or worsening of prior sinus and allergy symptoms. The second stage of CSS involves acute asthma. The third and final stage involves various organs like the kidneys, lung, heart and digestive system. The third stage of CSS is considered painful and life threatening. However, patients can live for many years in the first two stages.
Although CSS is a lifelong and chronic disease,  the illness  can be managed with steroids like glucocorticoids and immunosuppressive drugs. In many cases, CSS can be forced into chemical remission by drug therapy.

SIADH

SIADH stands for Syndrome of Inappropriate Antidiuretic Hormone Hypersecretion. It is also referred to as Schwartz- Bartter syndrome. In SIADH the posterior pituitary gland (or some other source), releases excessive vasopressin or ADH, antidiuretic hormone. Excessive secretion causes fluid overload and hyponatremia. Hyponatremia refers to the concentration of sodium levels becoming lower than normal in the serum (which consequently causes electrolyte disturbance).

SIADH is mainly found In patients suffering from brain tumors, pneumonia, meningitis, strokes, head trauma, encephalitis  or lung small-cell carcinoma.

Treatment for SIADH involves treatment of the underlying causes fluid restriction to increase the level of sodium. This is a long –term restriction, giving intravenous saline to patients who are considered very symptomatic with convulsions, severe confusion, coma etc. Drugs like Demeclocycline, Urea, Conivaptan and Tolvaptan are given to patients depending upon their specific needs.

Summary

  1. CSS is a syndrome which involves necrosis of small and medium vessels, due to autoimmune vasculitis whereas SIADH involves excessive secretion of ADH or antidiuretic hormones.
  2. CSS stands for Churg-Strauss syndrome; it is also referred to as Allergic Granulomatosis. SIADH stands for syndrome of inappropriate antidiuretic hormone hypersecretion; it is also referred to as Schwartz- Bartter.
  3. CSS mainly involves blood vessels of gastrointestinal system, lungs and the peripheral nervous system. It affects the skin, heart, and kidneys as well. CSS is categorized as a rare disease, and is non-transmissible and non- inheritable. In SIADH,  excessive secretion causes fluid overload and hyponatremia. Hyponatremia refers to the concentration of sodium levels becoming lower than normal in the serum, causing electrolyte disturbance.
  4. CSS is a lifelong and chronic disease, but can be treated with steroids like glucocorticoids and immunosuppressive drugs. In SIADH drugs like Demeclocycline, Urea, Conivaptan and Tolvaptan are given to patients along with fluid restrictions etc.