What is the proper technique for administering an intralesional (directly into the lesion) injection of triamcinolone acetonide (a corticosteroid) for a patient with hidradenitis suppurativa?

Intralesional Corticosteroid Injection Technique for Hidradenitis Suppurativa

Inject triamcinolone acetonide 10 mg/mL (0.2-2.0 mL per lesion) directly into carefully selected, acute inflammatory HS nodules or abscesses during active flares, using ultrasound guidance when available to improve response rates. 1, 2

Patient Selection and Timing

Reserve intralesional corticosteroid injections for individual, acute inflammatory lesions during active flares—not for chronic scarring, sinus tracts, or multiple widespread lesions. 1

• Target isolated inflammatory nodules or abscesses in Hurley Stage I or II disease that require rapid symptom relief 1, 2
• This is an adjunctive therapy, not a standalone treatment for moderate-to-severe HS 1
• In pediatric patients, consider age and procedural tolerance, using appropriate pain management and distraction techniques 1

Preparation and Medication Selection

Use triamcinolone acetonide 10 mg/mL as the standard concentration for HS lesions. 1, 2, 3

• The 10 mg/mL concentration is preferred over higher concentrations (40 mg/mL) based on acne literature and to minimize atrophy risk 1
• Volume ranges from 0.2-2.0 mL depending on lesion size 1, 2
• May dilute with sterile normal saline to 5 or 3.3 mg/mL for smaller lesions or areas at higher risk of atrophy 1

Contraindications to Verify

• Active infection at injection site (impetigo, herpes) 1
• Previous hypersensitivity to triamcinolone 1
• Active tuberculosis or systemic fungal infection for large-volume injections 1

Injection Technique

Inject the corticosteroid directly into the center of the inflammatory lesion using a small-gauge needle (25-30 gauge), advancing slowly while injecting to distribute medication throughout the lesion. 1, 2, 3

Step-by-Step Approach:

• Cleanse the skin with alcohol or chlorhexidine 1
• Consider ultrasound guidance before injection—high-frequency ultrasound scanning significantly improves response rates (complete response in 70% vs lower rates without imaging) 3
• Insert needle at the base or center of the inflammatory nodule/abscess 1, 2
• Inject slowly while withdrawing slightly to distribute medication throughout the lesion 1, 2
• Avoid injecting into surrounding normal skin to minimize atrophy risk 1
• Apply gentle pressure post-injection 1

Ultrasound-Guided Technique (When Available):

Ultrasound guidance before intralesional injection improves complete response rates to 70.37% compared to blind injection. 3

• Use high-frequency ultrasound (HFUS) to visualize lesion depth, extent, and fluid collections 3
• Identify optimal injection site and avoid inadvertent injection into surrounding structures 3
• This is particularly valuable for deeper lesions or fistulous tracts 3

Expected Outcomes and Follow-Up

Patients should experience significant pain reduction within 24 hours (VAS score dropping from 5.5 to 2.3) and visible improvement in inflammation by 7 days. 1, 2

• Physician-assessed erythema, edema, suppuration, and lesion size significantly improve at follow-up 1, 2
• Complete or partial response occurs in approximately 95% of appropriately selected lesions 3
• Reassess at 1-2 weeks to determine need for repeat injection 4, 3

Important Caveat About Efficacy:

One recent double-blind RCT (2020) found no significant difference between triamcinolone 10 mg/mL, 40 mg/mL, and normal saline for days to clearance or pain reduction, suggesting intralesional steroids may be less effective than traditionally presumed. 5

• This contradicts earlier prospective case series and clinical experience 1, 2
• The British Association of Dermatologists still recommends considering intralesional corticosteroids based on overall evidence, but acknowledges limitations 1
• Clinical judgment is essential—if no response after first injection, do not repeat 5

Combination Approach (Advanced Technique)

Consider combining triamcinolone with lincomycin (antibiotic) for intralesional injection under ultrasound guidance, administered at baseline and 2 weeks later. 4

• This combination improved VAS pain scores from 4.6 to 1.5 and SF-36 Bodily Pain scores from 36.2 to 53.9 at 4 weeks 4
• Over 90% of patients reported satisfaction scores ≥8/10 4
• This approach addresses both inflammation and bacterial colonization 4

Critical Pitfalls to Avoid

Do not inject large volumes or use high concentrations (40 mg/mL) in thin-skinned areas or superficial lesions—this causes atrophy, pigmentary changes, and telangiectasias. 1

• Local overdose results in permanent skin atrophy 1
• Repeated injections can suppress the hypothalamic-pituitary-adrenal axis 1
• Do not use intralesional steroids as monotherapy for patients with multiple lesions—they require systemic therapy 1
• Avoid injecting chronic fibrotic nodules or established sinus tracts, as response is poor 1, 3

Integration with Overall Treatment Plan

Intralesional corticosteroids are an adjunctive therapy for acute flares, not a replacement for systemic treatment in moderate-to-severe disease. 1

• Patients with Hurley Stage I should receive topical clindamycin 1% twice daily as baseline therapy 1, 6
• Patients with Hurley Stage II require systemic antibiotics (clindamycin 300 mg + rifampicin 300-600 mg twice daily for 10-12 weeks) 1, 6
• Patients with Hurley Stage III or failed conventional therapy need adalimumab 40 mg weekly 1, 6