Is ertapenem (a broad-spectrum antibiotic) medically necessary for a patient with severe hidradenitis suppurativa, history of abscesses, and recent surgical procedure?

Medical Necessity of Ertapenem for Severe Hidradenitis Suppurativa with Active Infection

Ertapenem is medically necessary for this patient with severe hidradenitis suppurativa (Hurley stage III), recent surgical procedure with purulent drainage, and severe sepsis diagnosis. This represents a severe, recalcitrant case requiring rescue antibiotic therapy as recommended by North American guidelines.

Clinical Justification Based on Disease Severity

This patient presents with multiple high-risk features that mandate aggressive antibiotic intervention:

• Extensive disease burden: Bilateral buttocks and mid-lower back involvement with recent surgical drainage and ongoing purulent discharge indicates Hurley stage III disease 1
• Active infection with systemic involvement: The ICD-10 diagnosis of severe sepsis (R65.20) combined with visible purulent drainage represents acute infectious complications requiring immediate broad-spectrum coverage 1
• Quadriplegia with limited mobility: This significantly increases infection risk and impairs wound healing, making aggressive medical management essential to prevent progression to septic shock 1
• Failed conventional therapies: Prior treatment with antibiotics, biologics (Cosentyx/secukinumab), and laser therapy without adequate control establishes this as refractory disease 1

Guideline-Supported Indication for Ertapenem

The 2019 North American Clinical Management Guidelines explicitly recommend IV ertapenem for severe disease as rescue therapy or bridge to surgery, which precisely matches this clinical scenario 1:

• Ertapenem 1 gram IV daily is indicated for severe HS as a one-time rescue therapy or bridge to definitive surgical management 1
• The 2025 guidelines further support ertapenem use in patients with history of malignancy requiring systemic antibiotics for severe, recalcitrant cases, demonstrating its safety profile in complex patients 1
• Standard duration is 6 weeks based on the highest quality evidence showing dramatic improvement in severe HS 2

Evidence for Clinical Efficacy

The strongest research evidence demonstrates substantial benefit in this exact patient population:

• In 30 consecutive patients with severe HS treated with ertapenem 1g daily for 6 weeks, the median Sartorius score dropped from 49.5 to 19.0 (P < 10^-4), with 59% of HS areas reaching clinical remission when followed by consolidation therapy 2
• Ertapenem provides broad-spectrum coverage against the polymicrobial anaerobic abscesses characteristic of severe HS 2
• A 2024 case report demonstrated successful perioperative use of ertapenem 1g/day for 6 weeks in a patient with Hurley stage III HS requiring invasive cardiac procedure through affected inguinal area, preventing infectious complications 3

Treatment Algorithm for This Patient

Immediate management (Days 1-42):

• Initiate ertapenem 1 gram IV daily for 6 weeks as rescue therapy 1, 2
• Continue appropriate wound care with dressings for draining lesions 1
• Optimize diabetes management as this directly impacts HS outcomes 3
• Coordinate with surgery for definitive excision planning during or after antibiotic course 1

Post-ertapenem consolidation (Weeks 7-24):

• Transition to oral consolidation antibiotics (clindamycin 300mg + rifampicin 600mg daily) for 3-6 months to prevent relapse, as 59% of patients achieved remission only with continuous consolidation 2
• Alternatively, consider triple therapy (moxifloxacin + metronidazole + rifampin) if clindamycin/rifampin previously failed 1
• Restart or optimize biologic therapy (adalimumab or alternative) for long-term disease control 1

Surgical planning:

• Coordinate radical surgical excision of affected areas once acute infection controlled 1
• Ertapenem serves as bridge to definitive surgery, which is essential for lasting cure in Hurley stage III disease 1

Critical Pitfalls to Avoid

• Do not use ertapenem as monotherapy without consolidation: Relapse is frequent after discontinuation; 16 patients who received continuous consolidation maintained improvement while 9 who interrupted treatment returned to baseline 2
• Do not delay surgical consultation: Medical therapy alone rarely achieves lasting cure in Hurley stage III disease; surgery remains cornerstone treatment 1
• Avoid inadvertent intravascular injection: When administering ertapenem intramuscularly (not applicable here with IV route), caution is required per FDA labeling 4
• Monitor for seizures and CNS adverse effects: Particularly relevant given patient's neurological baseline with quadriplegia 4
• Do not co-administer with valproic acid: Ertapenem reduces valproic acid levels, increasing seizure risk 4

Addressing Sepsis Diagnosis

The severe sepsis diagnosis (R65.20) elevates this from elective HS management to urgent infectious disease treatment:

• Broad-spectrum coverage with ertapenem addresses polymicrobial anaerobic infection typical of severe HS with abscess formation 2
• The combination of purulent drainage, recent surgery, and systemic sepsis criteria mandates aggressive IV antibiotic therapy beyond oral options 1
• Quadriplegia increases risk of progression to septic shock, making early aggressive intervention critical for mortality reduction 1

Quality of Life and Functional Considerations

This patient's quadriplegia makes HS management particularly challenging and medically necessary:

• Inability to perform self-care increases infection risk and wound complications 3
• Buttock involvement directly impacts pressure areas for wheelchair-bound patient, risking pressure ulcer development 3
• Chronic pain from HS significantly impairs already-limited quality of life in quadriplegic patients 1
• Ertapenem therapy can dramatically improve severe HS and quality of life when combined with appropriate surgical management 2

Regulatory and Safety Profile

Ertapenem is FDA-approved for complicated skin and skin structure infections, which encompasses severe HS with infectious complications 4:

• Approved for moderate to severe infections in adults and pediatric patients ≥3 months 4
• Standard dosing: 1 gram once daily IV infused over 30 minutes 4
• No dose adjustment needed unless advanced renal impairment (CrCl <30 mL/min/1.73m²) 4
• Contraindicated only in β-lactam anaphylaxis or lidocaine hypersensitivity (for IM route) 4

This represents appropriate, guideline-concordant, evidence-based use of ertapenem for a severe, life-threatening complication of hidradenitis suppurativa in a high-risk patient population. 1, 2