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Silver Nitrate: What a picture?
948
S. Ozmen et al.
CLINICAL TIP Silver Nitrate: What a picture? A 46 year old, right hand dominant grocer, attended the Accident and Emergency department with a one month history of a lesion over the dorsal aspect of the interphalangeal joint of his right thumb. Over the past week it had increased in size and was more painful, despite a course of antibiotics prescribed by his general practitioner. On examination, the lump was noted to be fluctuant, hence an incision and drainage was performed under local anaesthetic. However, no pus was found, but a provisional diagnosis of pyogenic granuloma was made and the lesion cauterised with silver nitrate. The patient was then referred to our department for further management. Two days later, the wound edges were noted to be necrotic and a collection had developed. However, the patient did not consent to further intervention or admission and was discharged with oral antibiotics with a request to return for subsequent review the next day. On his return, the fluctuance and tenderness had resolved, and it was decided to review the patient again in two days time. At the next attendance, the patient admitted to attempting to lance the lesion with a needle some weeks previously. In light of this and the chronicity of the lesion, an x-ray film was taken of the thumb to rule out a foreign body. The x-ray showed a circular, radiodense object corresponding to the site of the lesion. (Figure 1A). The wound was explored under local anaesthetic and some granulation tissue excised for microbiology, but no metallic foreign body was found. However, an immediate repeat X-ray demonstrated resolution of the
suspected foreign body. (Figure 1B). The wound was dressed and loosely closed with 5-0 ethilon. There were no further problems and the patient was discharged from the clinic five weeks later. Silver nitrate is commonly used in medicine as a chemical cautery and as an anti-microbial. It absorbs the electromagnetic radiation of X-rays and so appears radiodense. It is hypothesised that the foreign body on the radiograph was a result of the treatment with silver nitrate six days earlier, as this would account for the negative surgical findings but radiological resolution of the lesion. To confirm this hypothesis, a silver nitrate stick was moistened and applied to an aquacell pad and an x-ray film was taken (Figure 1C). This clearly shows how radiodense silver nitrate appears after application. The true nature of this case was obscured by the lack of grey/black staining of organic tissue that normally occurs with the use of silver nitrate sticks.1 The British National Formulary provides no warning regarding the potential for misinterpretation of X-ray examinations. A literature search has revealed only 2 cases of the mistaken diagnosis of silver nitrate as a foreign body.2,3 There has been no report in Plastics hand surgery journals. We suggest that cautious interpretation of radiological examination after silver nitrate use is required in order to avoid inappropriate surgical exploration.
References 1. Mehta D. British National Formulary. London: British Medical Association & the Royal Pharmaceutical Society of Great Britain; 2003. 563. 2. Madan SI, Heilpern KL. Silver nitrate as a radiopaque foreign body. J. Emerg. Med 1999;17:1045. 3. Healy C, Canney M, Murphy A, et al. Silver nitrate masquerading as a radiopaque foreign body. Emerg. Radiol 2007;14:63e4.
D. Kulendren W. Gossage P. Jayakumar M. Griffiths Department of Plastic & Reconstructive Surgery, 2nd Floor John Harrison House, The Royal London Hospital, Barts & The London NHS Trust, London E1 1BB, United Kingdom E-mail address: [email protected] Figure 1 A. X-ray of right thumb showing radiopaque foreign body pre-exploration. B. X-ray post-debridement showing no further radiopaque foreign material. C. X-ray of radiodense silver nitrate tip.
ª 2008 Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. doi:10.1016/j.bjps.2008.05.001
S. Ozmen et al.
CLINICAL TIP Silver Nitrate: What a picture? A 46 year old, right hand dominant grocer, attended the Accident and Emergency department with a one month history of a lesion over the dorsal aspect of the interphalangeal joint of his right thumb. Over the past week it had increased in size and was more painful, despite a course of antibiotics prescribed by his general practitioner. On examination, the lump was noted to be fluctuant, hence an incision and drainage was performed under local anaesthetic. However, no pus was found, but a provisional diagnosis of pyogenic granuloma was made and the lesion cauterised with silver nitrate. The patient was then referred to our department for further management. Two days later, the wound edges were noted to be necrotic and a collection had developed. However, the patient did not consent to further intervention or admission and was discharged with oral antibiotics with a request to return for subsequent review the next day. On his return, the fluctuance and tenderness had resolved, and it was decided to review the patient again in two days time. At the next attendance, the patient admitted to attempting to lance the lesion with a needle some weeks previously. In light of this and the chronicity of the lesion, an x-ray film was taken of the thumb to rule out a foreign body. The x-ray showed a circular, radiodense object corresponding to the site of the lesion. (Figure 1A). The wound was explored under local anaesthetic and some granulation tissue excised for microbiology, but no metallic foreign body was found. However, an immediate repeat X-ray demonstrated resolution of the
suspected foreign body. (Figure 1B). The wound was dressed and loosely closed with 5-0 ethilon. There were no further problems and the patient was discharged from the clinic five weeks later. Silver nitrate is commonly used in medicine as a chemical cautery and as an anti-microbial. It absorbs the electromagnetic radiation of X-rays and so appears radiodense. It is hypothesised that the foreign body on the radiograph was a result of the treatment with silver nitrate six days earlier, as this would account for the negative surgical findings but radiological resolution of the lesion. To confirm this hypothesis, a silver nitrate stick was moistened and applied to an aquacell pad and an x-ray film was taken (Figure 1C). This clearly shows how radiodense silver nitrate appears after application. The true nature of this case was obscured by the lack of grey/black staining of organic tissue that normally occurs with the use of silver nitrate sticks.1 The British National Formulary provides no warning regarding the potential for misinterpretation of X-ray examinations. A literature search has revealed only 2 cases of the mistaken diagnosis of silver nitrate as a foreign body.2,3 There has been no report in Plastics hand surgery journals. We suggest that cautious interpretation of radiological examination after silver nitrate use is required in order to avoid inappropriate surgical exploration.
References 1. Mehta D. British National Formulary. London: British Medical Association & the Royal Pharmaceutical Society of Great Britain; 2003. 563. 2. Madan SI, Heilpern KL. Silver nitrate as a radiopaque foreign body. J. Emerg. Med 1999;17:1045. 3. Healy C, Canney M, Murphy A, et al. Silver nitrate masquerading as a radiopaque foreign body. Emerg. Radiol 2007;14:63e4.
D. Kulendren W. Gossage P. Jayakumar M. Griffiths Department of Plastic & Reconstructive Surgery, 2nd Floor John Harrison House, The Royal London Hospital, Barts & The London NHS Trust, London E1 1BB, United Kingdom E-mail address: [email protected] Figure 1 A. X-ray of right thumb showing radiopaque foreign body pre-exploration. B. X-ray post-debridement showing no further radiopaque foreign material. C. X-ray of radiodense silver nitrate tip.
ª 2008 Published by Elsevier Ltd on behalf of British Association of Plastic, Reconstructive and Aesthetic Surgeons. doi:10.1016/j.bjps.2008.05.001