Silver nitrate is a natural, inorganic chemical compound with antimicrobial properties that has been used in medical applications since the 13th century. It is used as a cauterizing agent and is available as a solution or an applicator stick. The applicator sticks, known as silver nitrate sticks or caustic pencils, contain silver nitrate and potassium nitrate. There are certain brands of silver nitrate sticks that can be bent or shaped to increase ease of access within a target area. The silver nitrate stick is activated by contact with moisture. When applied to wounds, silver nitrate sticks deliver free silver ions to the tissue that form an eschar as they bind to tissue and obstruct vessels.¹

Indications for Use

The cauterizing action of silver nitrate sticks is considered an effective and rapid means of accelerating the clotting process to achieve hemostasis.² There are numerous indications, including:

• Non-genital warts, verrucas, skin tags: The chemical reaction of silver nitrate permanently destroys the targeted tissue.
• Anterior epistaxis (nosebleed): The stick is applied to the blood vessel or mucous membrane in the nostril in emergency medicine to control nosebleeds.
• Post-biopsy cervical nicks or cervical ectropion: Silver nitrate is applied to the cervix to seal off cells responsible for bleeding.
• Hypergranulation tissue (overgranulation, exuberant, or proud flesh tissue): Silver nitrate is used to treat granulation tissue in wounds and stoma sites.
• Painful aphthous stomatitis: A single treatment with silver nitrate sticks is used to help provide pain relief.³
• Vasomotor rhinitis: Treatment by silver nitrate sticks is applied to the trigger area of the nasal mucosa.⁴
• Umbilical stumps: Infectious lesions and granulomas treated with silver nitrate will dry up and fall off.
• Skin ulcers: Silver nitrate may be applied to chronic wounds to aid healing.⁵
• Wound epibole: Applied to epibole, silver nitrate may renew the healing process.⁶

Procedure for Use

Silver nitrate sticks come in the form of wooden sticks with 75% silver nitrate and 25% potassium nitrate on the tip. The chemical compounds are activated with moisture either through the application of water or by contacting a moist membrane or wound. When treating with silver nitrate sticks, the hands are first washed thoroughly with soap and water before putting on nitrile gloves (vinyl gloves do not provide protection from burns or staining). The application site is prepared by removing the wound dressing (if treating a wound), and then the wound or target site is cleaned with sterile saline solution or an approved wound cleanser. Following cleansing, any excess moisture is removed from the treatment site.

The area to be treated should be isolated, and the surrounding tissue should be protected through the application of a barrier such as petroleum jelly. If there is adequate moisture at the treatment site, then the stick can be used dry; otherwise, the tip must be moistened with sterile distilled or de-ionized water. The use of saline solution to moisten the tip of the stick should be avoided because this may decrease the effectiveness of the silver nitrate. The stick should be applied to the wound with a gentle, rolling motion. Two minutes of application time is usually sufficient, but treatment will vary case by case.

The length of time that the tip contacts the tissue determines the degree of the resulting caustic action. When silver nitrate sticks are used for cauterization, it may be necessary to apply some pressure during treatment. The patient is monitored carefully, and treatment is stopped if the burning sensation is too great. After the procedure, damp saline gauze can be used to clean the treatment area gently, patting dry to minimize trauma to the surrounding tissue. Once gloves have been removed and replaced, an appropriate wound dressing can be applied. Depending on the procedure, a wound dressing may support hemostasis or encourage a minimally moist wound environment. The frequency of silver nitrate treatment varies depending on wound needs. In cases of cauterization to control bleeding, a single application should be sufficient. When treating hypergranulation tissue or epibole, the procedure may need to be repeated daily to three times a week, depending on the result.

Precautions

Silver nitrate is corrosive to both clothing and skin, and protective measures should be taken to protect both while treating with silver nitrate sticks. Any contamination of healthy skin with silver nitrate can be resolved by rinsing the area immediately with saline solution. Silver nitrate is an effective tool for treating a number of specific conditions but must be used with caution to achieve optimal results.

References

1. Ho C, Argáez C. Topical Silver Nitrate for the Management of Hemostasis: A Review of Clinical Effectiveness, Cost-Effectiveness, and Guidelines. Ottawa, Canada: Canadian Agency for Drugs and Technologies in Health; 2018. https://www.ncbi.nlm.nih.gov/books/NBK537873/. Accessed January 14, 2020.

2. Howe N, Cherpelis B. Obtaining rapid and effective hemostasis: part I. Update and review of topical hemostatic agents. J Am Acad Dermatol. 2013;69(5):659.e651-659.e617.

3. Bagan JV, Sanchis JM, Milian MA, et al. Recurrent aphthous stomatitis. A study of the clinical characteristics of lesions in 93 cases. J Oral Pathol Med. 1991;20:395-397

4. al-Samarrae SM. Treatment of 'vasomotor rhinitis' by the local application of silver nitrate. J Laryngol Otol. 1991;105:285-287.

5. Moir J, Serra MP. The use of silver nitrate in wound management. Ann Ital Chir. 2012;83(1):45-48.

6. Black J, Baharestani M, Black S, et al. An overview of tissue types in pressure ulcers: a consensus panel recommendation. Ostomy Wound Manage. 2010;56(4):28-44.