What is the correct dosage for triamcinolone acetonide (corticosteroid) injections in treating acne and keloids?

Triamcinolone Acetonide Dosing for Acne and Keloids

Acne Nodules

For inflammatory nodular acne, inject triamcinolone acetonide at 10 mg/mL (which may be diluted to 5 or 3.3 mg/mL with sterile normal saline), using 0.05-0.1 mL per injection site. 1

• This concentration provides rapid symptom relief within 48-72 hours for individual stubborn cystic lesions 1
• The injection should be placed just beneath the dermis in the upper subcutis 2
• Each 0.05-0.1 mL injection produces a response area approximately 0.5 cm in diameter 1
• Intralesional corticosteroid injections are effective for treating individual acne nodules, particularly in patients at risk of scarring who require rapid improvement in inflammation and pain 2, 1

Important Limitations for Acne Treatment

• This approach is not effective as primary treatment for multiple lesions—use it judiciously for occasional stubborn cystic lesions only 1
• Treating multiple acne lesions with intralesional steroids is not an effective strategy 1

Keloids and Hypertrophic Scars

For keloids, the standard concentration is triamcinolone acetonide 40 mg/mL injected intralesionally, though lower concentrations of 5-10 mg/mL may be used depending on lesion characteristics and to reduce atrophy risk. 1

Dosing Protocol

• Inject just beneath the dermis in the upper subcutis 1
• Administer at monthly intervals 3
• Treatment duration typically extends 6-8 months 4, 3
• The response to corticosteroid injection alone is variable with 50-100% regression 5

Recurrence and Efficacy Concerns

• Monotherapy with triamcinolone alone yields poor long-term results with recurrence rates of 33% at 1 year and 50% at 5 years 5
• Triamcinolone alone showed only 15-20% good to excellent improvement rates in comparative studies 4

Combination Therapy for Keloids (Preferred Approach)

The combination of triamcinolone acetonide 40 mg/mL with 5-fluorouracil 50 mg/mL in a 1:1 ratio is more effective than either agent alone and produces fewer side effects. 1, 4, 3

Specific Combination Protocol

• Mix 0.1 mL of triamcinolone acetonide 40 mg/mL with 0.9 mL of 5-fluorouracil 50 mg/mL 4
• Inject weekly for 8 weeks, then reassess 4
• This combination achieved 40-55% good to excellent improvement compared to 15-20% with triamcinolone alone 4
• A more recent study showed 95% good to excellent response with the combination versus 70% with triamcinolone alone 3

Why Combination Therapy is Superior

• Combination therapy shows better outcomes with fewer side effects than either agent alone 1
• The combination produces faster response and more stable long-term results 5, 3
• Adding pulsed-dye laser to the triamcinolone/5-FU combination further improves outcomes to 70-75% good to excellent response 4

Adverse Effects and Risk Mitigation

Local Complications

• Skin atrophy occurs in 44% of patients treated with triamcinolone alone but only 8% with 5-FU alone 6
• Telangiectasias develop in 50% with triamcinolone versus 21% with 5-FU 6
• Pigmentary changes (both hypopigmentation and hyperpigmentation) can occur 1
• Atrophy and telangiectasia were seen in 37% of patients receiving triamcinolone alone for keloids 4

Strategies to Minimize Adverse Effects

• Use lower concentrations and volumes to reduce atrophy risk 1
• Decreasing concentration from 40 mg/mL to 10 mg/mL or diluting to 5 mg/mL significantly reduces atrophy risk 1
• Avoid injecting too superficially, as this dramatically increases the risk of atrophy and pigmentary changes 1
• Do not use excessive concentration or volume 1

Systemic Complications

• Hypothalamic-pituitary-adrenal axis suppression can occur with repeated injections 1
• Rare cases of anaphylaxis, angioedema, and urticaria have been reported 1
• Consider impaired wound healing and increased infection risk at injection sites 1

Clinical Pitfalls to Avoid

• Never inject too superficially—this increases atrophy and pigmentary change risk 1
• Avoid using triamcinolone monotherapy for keloids—combination therapy is superior 1, 5
• Do not attempt to treat multiple acne lesions with intralesional steroids—this is ineffective 1
• Do not use excessive volumes—stick to 0.05-0.1 mL per injection site 1