What is a granuloma?

A stomal granuloma is a small red lump that is found on or around the edge of the stoma (an opening that connects the bowel to the surface of the stomach). It can be caused by an excess of granulation tissue over the surface of the skin or friction from the stoma pouch. A granuloma may cause bleeding and may prevent the pouch from sticking properly to your skin if the granuloma is large. This may also cause problems of stool leakage.

What is silver nitrate?

Silver nitrate is a topical treatment that is used directly on the skin to cauterise (burn) tissue around a wound to treat over granulation of skin. It can also be used to help stop or reduce bleeding.

Are there any side effects?


In some cases, the use of silver nitrate can cause a mild skin injury and the skin may appear red and burnt. This will normally heal within three to six days.

Rare or very rare

Argyria is a very rare condition caused by the build-up of silver in the body over a long period of time, this could be after a few months or years depending on the dose you receive. Argyria can cause a blue-grey discolouration of the skin, eyes, and internal organs, especially in areas of the body exposed to sunlight.

Over exposure of silver nitrate over a long period of time can also cause a very rare condition called methaemoglobin. This is a form of abnormal haemoglobin found in red blood cells. In patients with methaemoglobinaemia, haemoglobin which normally carries oxygen is not able to release the oxygen effectively to body tissues. This can cause symptoms such as headaches, shortness of breath, nausea, rapid heart rate, fatigue and lethargy, and confusion or loss of consciousness.

Applying silver nitrate to the skin

Silver nitrate is applied to the skin with an applicator stick and you may find this process uncomfortable or painful due to the cauterising agent in the product.

The skin around granulomas may take on a bluish-black appearance but this is harmless.

Clothing around the area may also become permanently stained during application so we advise that old clothing is worn when having this treatment.

Stomal granulomas are normally treated once a week for four weeks by your stoma clinical nurse specialist who will also review the progress of your treatment regularly. It may take longer to show improvement depending on the size and condition of your granulomas.

If you notice any reactions to the treatment that concern you, contact the Royal Free Hospital stoma team (details can be found below). Silver nitrate treatment may not be suitable for your stomal granulomas if you have one or more of the following:

  • Broken skin
  • A known allergy or hypersensitivity to silver
  • If you have previously experienced a severe reaction to silver nitrate treatment

Is there an alternative treatment available?

If the treatment has not improved your symptoms after four weeks, you may be referred to the dermatology service or colorectal surgical team for further advice.