Will a large fluid-filled blister under the skin of a finger, following incision and drainage with intravenous (IV) cefazolin (Ancef) for finger cellulitis caused by group A streptococcus, resorb on its own or require repeat drainage?

From the Guidelines

The patient with a large fluid-filled blister under the skin of his finger following treatment for cellulitis will likely need a repeat drainage procedure. While small blisters may resorb on their own, large collections of fluid typically require intervention, especially in the context of a recent infection. I recommend having the blister drained by a healthcare provider to prevent potential complications. The procedure would involve sterile technique to aspirate or incise the blister, followed by appropriate wound care. The patient should continue the prescribed cefazolin to complete the full course of antibiotics (typically 7-10 days total) since the culture confirmed Group A Streptococcus as the causative organism, as suggested by the guidelines for the treatment of skin and soft tissue infections 1. After drainage, the patient should keep the area clean and dry, change dressings as instructed, and monitor for signs of recurrent infection such as increasing redness, warmth, pain, or purulent drainage. Large fluid collections can serve as potential media for bacterial growth and may impair healing if left undrained. Additionally, the pressure from the fluid can cause pain and potentially damage surrounding tissues, particularly in the confined space of a finger. It is also important to note that the management of skin and soft tissue infections, including the decision to drain a blister, should be guided by the principles outlined in the clinical practice guidelines for the treatment of methicillin-resistant Staphylococcus aureus infections in adults and children 1. However, in this case, the primary concern is the management of the blister and the completion of the antibiotic course, rather than the specific treatment of MRSA, as the culture results indicate Group A Streptococcus as the causative organism. Therefore, the focus should be on preventing complications and promoting healing, with careful monitoring for any signs of recurrent or worsening infection.

From the Research

Management of Cellulitis and Abscesses

• The patient's condition, with significant clinical improvement after IV cefazolin and incision/drainage, and a wound culture growing group A strep, suggests effective initial treatment 2, 3.
• The development of a large fluid-filled blister under the skin of the finger may be a complication of the infection or a reaction to the treatment.
• There is no direct evidence in the provided studies to suggest that the blister will resorb on its own or require repeat finger drainage 2, 3, 4, 5.
• The management of cellulitis and abscesses typically involves antibiotic treatment and incision and drainage, with adjunctive antibiotics considered in some cases 2, 3.
• The choice of antibiotic is determined by patient history, risk factors, and the most likely microbial culprit, with no evidence to support the superiority of any one antibiotic over another 4.

Considerations for Further Treatment

• The patient's response to initial treatment and the presence of a wound culture growing group A strep suggest that the infection is being effectively managed 2, 3.
• The development of a fluid-filled blister may require further evaluation and management, potentially including repeat incision and drainage or other interventions 2, 3.
• The use of intravenous antibiotics over oral antibiotics and treatment duration of longer than 5 days are not supported by evidence, and the narrowest possible antimicrobial therapy is ideal for individual patient outcomes and public health 4, 5.