Managing Injection Abscess: Insights from a Single Case Study in Outpatient Care

Introduction

An injection abscess is a localized collection of pus that usually develops following a non-sterile intramuscular injection, improper injection technique, or due to a thick fat pad in the dorsogluteal region. Worldwide, nearly 40% of intramuscular injections are considered unsafe, while in India, approximately 40–60% of injections are unsafe. Injection-site abscesses account for nearly 7.3% of total abscess cases in India.

Although many injections are administered safely, an injection abscess can become painful and may require drainage and antibiotic therapy if not treated promptly.

Injection Abscess

An injection abscess is a localized collection of pus that develops following an intramuscular injection due to bacterial infection or tissue reaction. It commonly occurs in the buttocks (gluteal region), thighs, arms, and deltoid region.

Causes

Injection abscesses are broadly divided into two types:

1.     Infectious causes

2.     Non-infectious causes

1. Infectious Causes

Infectious causes include:

·        Use of non-sterile needles

·        Contaminated needles and syringes

·        Poor skin cleaning before injection

·        Reuse of syringes

2. Non-Infectious Causes

Non-infectious causes include:

·        Improper injection technique

·        Irritating medications

·        Oil-based injections

·        Thick fat pad in the dorsogluteal region compared to the needle size

Other contributing factors may include comorbid conditions such as diabetes mellitus and immunocompromised status.

Symptoms

Symptoms may include:

·        Pain at the injection site

·        Swelling

·        Redness

·        Fever

·        Pus discharge

·        Difficulty in walking, especially in cases of gluteal abscess

Diagnosis

Diagnosis of an injection abscess can often be made through detailed history-taking and clinical examination by an experienced doctor. However, definitive diagnosis may require investigations such as:

·        Complete blood count (CBC)

·        Ultrasonography

·        Pus culture and sensitivity testing

Management

Conservative Management

A small, early abscess may respond to:

·        Antibiotics

·        NSAIDs

·        Cold compresses

Surgical Management

A large abscess may require:

·        Incision and drainage

·        Antibiotics

·        Regular dressings

Possible Complications

If not treated promptly, an injection abscess may lead to:

·        Cellulitis

·        Muscle damage

·        Sepsis

·        Scarring

·        Sinus formation

Case Presentation

A 43-year-old male presented to the OPD with complaints of pain and swelling in the right buttock for 4–5 days, associated with difficulty in walking, fever, and chills. On detailed history-taking, the patient reported receiving an intramuscular injection in the right buttock a few months earlier. He also gave a history of recurrent episodes of pain and swelling in the same region, which temporarily resolved with antibiotics and NSAIDs.

Image 1. Large swollen injection abscess over the right gluteal region showing redness, skin tension, and localized inflammation before incision and drainage.

Examination

The patient was conscious, alert, and febrile at the time of examination. Vital signs were grossly normal. Local examination of the gluteal region revealed a tender, fluctuant swelling.

On complete blood count examination, leucocytosis with neutrophilic predominance was observed. Ultrasonography was not performed, as the diagnosis was clinically evident based on detailed history and examination findings.

Management

Surgical incision and drainage were performed as an OPD-based procedure. A pus sample was collected for culture and sensitivity testing. The patient was discharged with oral empirical antibiotics and NSAIDs and was advised daily antiseptic dressings.

Image 2. Open gluteal injection abscess cavity during surgical incision and drainage procedure after evacuation of pus.

Pus culture and sensitivity testing showed growth of Pseudomonas after 48 hours of incubation at 37°C, with a colony count of 10⁴ CFU/mL. The organism was found to be sensitive to the empirically prescribed antibiotics.

Image 3. Post-drainage injection abscess wound showing healthy granulation tissue and early healing after regular antiseptic dressings.

Image 4. Pus culture and sensitivity report showing growth of Pseudomonas species from an injection abscess sample.

Conclusion

Injection abscesses are preventable complications commonly associated with unsafe injection practices, improper injection techniques, and poor aseptic precautions. Early recognition and timely management are essential to prevent complications such as cellulitis, sepsis, and sinus formation. This case highlights that proper clinical examination and prompt surgical intervention in the form of incision and drainage, combined with appropriate antibiotic therapy, can lead to successful outcomes even in an OPD setting. The case also emphasizes the importance of safe injection practices, adequate needle selection, and strict sterilization protocols to reduce the burden of injection-related complications.