How to dilute triamcinolone (intralesional corticosteroid) 10 mg/1 ml for acne injection procedure?

Dilution Protocol for Intralesional Triamcinolone in Acne

For acne nodules and cysts, dilute triamcinolone acetonide 10 mg/mL with sterile normal saline to either 5 mg/mL (1:1 dilution) or 3.3 mg/mL (2:1 dilution), with 2.5 mg/mL being the most commonly used concentration in clinical practice. 1, 2, 3

Standard Dilution Options

The American Academy of Dermatology guidelines provide three concentration options for treating inflammatory nodulocystic acne 1, 2:

• Undiluted: 10 mg/mL (use directly from vial)
• 5 mg/mL: Mix 1 mL of triamcinolone 10 mg/mL with 1 mL sterile normal saline (1:1 ratio)
• 3.3 mg/mL: Mix 1 mL of triamcinolone 10 mg/mL with 2 mL sterile normal saline (1:2 ratio)

The most commonly used concentration in actual dermatology practice is 2.5 mg/mL (52.5% of practitioners), which requires mixing 1 mL of triamcinolone 10 mg/mL with 3 mL sterile normal saline (1:3 ratio). 3

Injection Technique Specifications

Inject 0.05-0.1 mL per lesion just beneath the dermis in the upper subcutis, targeting the center of the inflammatory nodule. 1, 2, 3

• Each 0.05-0.1 mL injection produces therapeutic effect over approximately 0.5 cm diameter 1, 2
• 61.6% of dermatologists inject into the center of the lesion 3
• The most frequently used volume is 0.05 mL (42.3% of practitioners) 3

Concentration Selection Algorithm

Use lower concentrations (2.5-3.3 mg/mL) for routine acne nodules to minimize atrophy risk, reserving higher concentrations (5-10 mg/mL) only for particularly stubborn or larger lesions. 1, 2, 3

The rationale for dilution:

• Decreasing concentration from 10 mg/mL to 5 mg/mL or lower significantly reduces atrophy risk 2
• Lower concentrations maintain efficacy while improving safety profile 2, 3
• Skin atrophy occurred in 44% of patients treated with higher concentration triamcinolone 2

Critical Technical Points to Prevent Complications

Inject at the correct depth (upper subcutis, just beneath dermis) - injecting too superficially dramatically increases risk of visible atrophy and pigmentary changes. 2, 4

Additional precautions:

• Use minimal effective volume - excessive volume increases adverse effect risk 2
• This treatment is efficacious only for occasional stubborn cystic lesions, not as primary therapy for patients with multiple lesions 1, 2
• Expected response time is 48-72 hours for flattening of nodules 1, 2

Contraindications

Do not inject triamcinolone at sites with 1:

• Active infections (impetigo, herpes)
• Previous hypersensitivity to triamcinolone
• Active tuberculosis or systemic fungal infection (for large injections)

Adverse Effects Counseling

Counsel patients before every injection about potential hypopigmentation and atrophy, as 50.5% of dermatologists follow this practice. 3

Key adverse effect data:

• Less than 1% of patients return for adverse events in most practices (88.8% of respondents) 3
• When atrophy occurs, it typically lasts over 6 months (48.4% of cases) 3
• Local complications include atrophy, pigmentary changes (both hypo- and hyperpigmentation), telangiectasias, and hypertrichosis 1, 2
• Rare systemic effects include hypothalamic-pituitary-adrenal axis suppression with repeated injections 1, 2

Practical Preparation Steps

1. Draw up triamcinolone acetonide 10 mg/mL from stock vial
2. Add sterile normal saline in appropriate ratio (most commonly 1:3 for 2.5 mg/mL)
3. Mix thoroughly by gentle agitation
4. Use immediately or within same treatment session
5. Inject 0.05-0.1 mL per nodule into upper subcutis 1, 2