What is the cause of an abdominal rash in a patient following laparotomy and gastrointestinal stromal tumor (GIST) resection who had an antibiotic-impregnated dressing?

From the Guidelines

The abdominal rash following laparotomy and GIST (gastrointestinal stromal tumor) resection with antibiotic-impregnated dressing is most likely due to a contact dermatitis reaction to the antibiotics in the dressing. This represents a delayed hypersensitivity reaction to topical antibiotics commonly used in surgical dressings, such as bacitracin, neomycin, or gentamicin. Management should include immediate removal of the antibiotic-impregnated dressing and replacement with a non-medicated, hypoallergenic alternative such as plain gauze or silicone-based dressings. Topical corticosteroids like hydrocortisone 1% cream applied twice daily for 3-5 days can help reduce inflammation and itching. For more severe reactions, oral antihistamines such as cetirizine 10mg daily may provide additional relief. The reaction typically resolves within 1-2 weeks after removing the offending agent. This type of reaction occurs because the immune system recognizes components of the antibiotic as foreign antigens, triggering T-cell mediated inflammation in the skin. It's essential to document this reaction in the patient's medical record to avoid future exposure to the same antibiotic in topical preparations, as subsequent exposures may cause more severe reactions 1.

Some key points to consider:

• The use of antibiotic-impregnated dressings can increase the risk of contact dermatitis reactions, especially in patients with a history of allergies or sensitivities 1.
• The management of contact dermatitis reactions involves removing the offending agent and replacing it with a non-medicated alternative, as well as using topical corticosteroids and oral antihistamines to reduce inflammation and itching 1.
• It's crucial to document the reaction in the patient's medical record to avoid future exposure to the same antibiotic in topical preparations 1.
• The reaction typically resolves within 1-2 weeks after removing the offending agent, but it's essential to monitor the patient's condition and adjust the treatment plan as needed 1.

From the Research

Possible Causes of Abdominal Rash

• Surgical site infection (SSI) is a common complication of abdominal surgery, with a reported incidence of 16.3% in patients undergoing abdominal surgery 2
• The use of antibiotic-impregnated dressings may not be effective in preventing SSI, as shown in a study where 14% of patients developed SSI despite using a PICO dressing 3
• Intraoperative wound irrigation with antiseptics or saline has been debated as a method to reduce SSI rates, with some studies suggesting its effectiveness and others showing no difference 4
• The type of antibiotic prophylaxis used may play a role in reducing SSI rates, with a study showing a 46% decrease in infections related to trauma laparotomy after implementing a protocol using ertapenem 5

Risk Factors for Surgical Site Infection

• Open surgical approach, emergency operation, long operation duration, and male sex have been identified as independent predictors of SSI after abdominal surgery 2
• Contaminated wound class and emergency surgery are also potentially modifiable independent risk factors for SSI after abdominal surgery 2
• Patient characteristics such as body mass index (BMI), incision depth, and comorbidities may also affect the risk of SSI 3

Management of Surgical Site Infection

• Antibiotic therapy for the treatment of intra-abdominal infections, including SSI, should be tailored to the severity of the infection and the suspected or confirmed causative organisms 6
• A combination of surgical procedures and antibiotic therapy may be necessary to manage SSI, with a strong synergy between the two approaches representing the best way to resolve even the most severe infections 6