Sentinel lymph node (SLN) dissection has increased in use for the management of high-risk melanoma and other cancers, such as breast cancer. The procedure identifies an SLN by intradermal or intraparenchymal injection of a blue dye (either isosulfan blue or methylene blue), a radiocolloid, or both around the primary malignancy.
When isosulfan blue is used there is a 2% incidence of allergic reactions. These include "blue hives" and anaphylaxis. Because of these reactions, the use of methylene blue is becoming more wide spread as no toxicity has been attributed to it.
The use of methylene blue requires an intraparenchymal injection of 5 mL of 1% methylene blue dye. While methylene blue has had no systemic toxicity attributed to it, it has been associated with a local inflammatory reaction which may lead to skin necrosis at the site of injection. Stradling et al. reported skin lesions in 5 of 24 patients who received intradermal injection of methylene blue dye for lymphatic mapping in breast cancer. The skin lesions included a variety of local inflammatory presentations, including erythematous macular lesions, superficial ulcers, necrotic ulcerations, and abscess formation. After injections were restricted to the deep parenchyma, no further skin lesions were noted. This local toxicity of methylene blue with superficial injection concerns surgeons who perform subareolar injection because of its potential effect on the nipple/areolar complex.
Methylene Blue should not be given by subcutaneous, so try to inject into the deep dermis or subcutaneous layer. This should help prevent the skin complications.
"Some individuals have found that dilution of methylene blue (2 mL of methylene blue and 3 mL of saline) allows successful mapping while avoiding this local toxicity (Pat Whitworth, MD, personal communication, May 2004" -- from second reference article.
Treatment consists of basic wound care.
1) Keep the wound clean.
2) Keep the wound moist.
3) Keep the wound well nourished, which implies reducing or eliminating edema and keeping pressure off the wound.
4) Debride only as necessary, be conservative.
Methylene Blue Solution for Injection Data Sheet--MedSafe
Is Blue Dye Indicated for Sentinel Lymph Node Biopsy in Breast Cancer Patients With a Positive Lymphoscintigram?; Amy C. Degnim, MD, Kevin Oh, MD, Vincent M. Cimmino, MD, Kathleen M. Diehl, MD, Alfred E. Chang, MD, Lisa A. Newman, MD, MPH and Michael S. Sabel, MD; Annals of Surgical Oncology 12:712-717 (2005)
Adverse skin lesions after methylene blue injections for sentinel lymph node localization; Stradling B, Aranha G, Gabram S; Am J Surg 2002;184:350–2.
Allergic reactions to isosulfan blue during sentinel node biopsy – a common event; Cimmino VM, Brown AC, Szocik JF, Pass HA; Surgery. 2001;130:439–42. doi:10.1067/msy.2001.116407.
Dye Rashes; Raimer SS, Quevedo EM, Johnston RV; Cutis. 1999;63:103–106
The Role of Subareolar Blue Dye in Identifying the Sentinel Node in Patients with Invasive Breast Cancer by K. Mokbel and A. Mostafa-- MedScape Article