Overview
Definition:
Incision and drainage (I&D) of an abscess is a common surgical procedure to evacuate purulent material, relieving pressure and promoting healing
The loop drain technique, often employed in pediatric abscess management, utilizes a simple drain fashioned from a surgical tube or catheter to maintain patency of the incision, facilitate continuous drainage, and prevent early reaccumulation of pus.
Epidemiology:
Abscesses are common in pediatrics, particularly skin and soft tissue infections (SSTIs), with a reported incidence of up to 20% of all pediatric skin conditions
Bacterial etiology, often Staphylococcus aureus (including MRSA), is predominant
Location, size, and depth of the abscess influence management choices.
Clinical Significance:
Untreated or inadequately managed abscesses can lead to significant morbidity, including cellulitis, bacteremia, sepsis, osteomyelitis, and chronic fistulas
Prompt and effective drainage is crucial for symptom relief, preventing systemic spread, and optimizing wound healing, especially in the pediatric population where adherence to medical management can be challenging.
Clinical Presentation
Symptoms:
Localized pain and tenderness
Erythema and warmth over the affected area
Swelling or fluctuant mass
Fever and malaise may be present, especially with larger or deeper abscesses
Decreased appetite and irritability in infants and young children.
Signs:
A palpable, fluctuant mass
Skin changes including redness, swelling, and induration
Tenderness to palpation
Possible purulent discharge upon pressure
Signs of systemic illness like fever or tachycardia may be present
Regional lymphadenopathy can occur.
Diagnostic Criteria:
Diagnosis is primarily clinical, based on the presence of a localized, tender, fluctuant swelling with overlying inflammatory signs
While definitive criteria are not always formalized, the classic triad of erythema, warmth, and fluctuance strongly suggests an abscess.
Diagnostic Approach
History Taking:
Onset and progression of symptoms
Presence of trauma or foreign body
History of similar infections
Exposure to individuals with skin infections
Previous antibiotic use
Vaccination status
Underlying medical conditions like immunocompromise or diabetes.
Physical Examination:
Systematic examination of the affected area to assess size, location, depth, and fluctuance of the swelling
Palpation for tenderness and induration
Assessment for surrounding cellulitis
Examination of regional lymph nodes
Evaluation for signs of systemic infection.
Investigations:
Gram stain and culture of purulent material from the abscess for organism identification and antibiotic sensitivity testing are crucial
Blood counts may show leukocytosis
Imaging (ultrasound) can confirm the diagnosis, assess depth, and identify loculations, especially in deeper or less accessible abscesses.
Differential Diagnosis:
Cellulitis without frank pus
Hematoma
Soft tissue tumor
Foreign body reaction
Insect bite reaction
Musculoskeletal conditions like osteomyelitis or septic arthritis (if near a joint)
Cystic lesions.
Management
Initial Management:
Pain control with analgesics
Application of warm compresses
Systemic antibiotics are often initiated empirically, especially if there are signs of surrounding cellulitis or systemic involvement, but should not delay surgical drainage.
Surgical Management:
Indications for I&D include a palpable fluctuant mass, significant pain, or suspected deep infection
The procedure involves local anesthesia (infiltration or regional block), sterile preparation and draping
A linear incision is made over the point of maximal fluctuance
The abscess cavity is then gently probed with a hemostat or clamp to break down any loculations and ensure complete evacuation of pus
Irrigation with sterile saline is performed
A loop drain is fashioned using a Penrose drain or a size-appropriate catheter (e.g., Foley catheter tip cut off, or a small sump drain)
The drain is placed through the incision, looped back and secured to the skin with a stitch, creating a self-retaining or easily removable drainage system that maintains patency
The wound is loosely dressed.
Loop Drain Technique Details:
The loop drain is essential for pediatric abscesses to maintain continuous drainage and prevent early closure of the skin incision, which could lead to reaccumulation of pus
The loop is typically secured with a single suture to the skin edge
The length of the drain left in situ depends on the depth and size of the abscess, usually removed in 2-5 days once drainage subsides
Careful monitoring of the drain site is required.
Antibiotic Therapy:
Antibiotics are guided by culture and sensitivity results
For uncomplicated skin abscesses, initial empiric coverage should include MRSA coverage (e.g., trimethoprim-sulfamethoxazole, clindamycin)
Duration typically ranges from 5-10 days, adjusted based on clinical response
For severe infections or immunocompromised children, intravenous antibiotics may be required initially.
Supportive Care:
Regular wound care, including dressing changes
Monitoring for signs of recurrent infection or complications
Nutritional support
Parental education on wound care and signs of complications.
Complications
Early Complications:
Incomplete drainage leading to recurrence
Spread of infection (cellulitis, lymphadenitis, bacteremia, sepsis)
Injury to underlying structures during drainage
Bleeding
Necrotizing fasciitis (rare).
Late Complications:
Chronic draining sinus or fistula
Scarring
Recurrent abscess formation at the same site
Adhesions.
Prevention Strategies:
Complete evacuation of pus and breakdown of loculations
Thorough irrigation
Appropriate antibiotic therapy
Meticulous wound care
Close follow-up
Early recognition and management of any signs of complications.
Prognosis
Factors Affecting Prognosis:
Promptness of diagnosis and treatment
Adequacy of drainage
Virulence of the causative organism
Presence of underlying medical conditions
Compliance with antibiotic therapy and wound care.
Outcomes:
With appropriate management, most pediatric abscesses resolve completely, with minimal long-term sequelae
Good wound healing and resolution of infection are expected outcomes
Recurrence rates are reduced with effective drainage and appropriate antibiotic use.
Follow Up:
Follow-up appointments are typically scheduled 24-48 hours post-procedure to assess wound healing, drain function, and for drain removal
Further follow-up may be necessary depending on the severity of the initial infection and any developing complications.
Key Points
Exam Focus:
The loop drain technique is crucial for maintaining patency in pediatric abscess I&D to prevent early closure and reaccumulation
Prompt drainage is paramount
Suspect MRSA in community-acquired skin abscesses and choose antibiotics accordingly
Ultrasound is valuable for assessing deep or loculated abscesses.
Clinical Pearls:
Always probe for loculations after initial pus evacuation
Never close a drained abscess primarily
Use the smallest effective drain size
Loop drain secured with a single stitch is generally sufficient and easy to remove
Educate parents thoroughly on home wound care.
Common Mistakes:
Delaying drainage in favor of antibiotics alone
Inadequate drainage due to failure to break loculations
Premature removal of the drain
Inappropriate antibiotic selection or duration
Overlooking deep or unusual abscess locations
Not considering surgical intervention for complex pediatric abscesses.