Intralesional Triamcinolone for Active Acne Lesions
Yes, a patient can inject undiluted Kenalog (triamcinolone) 10 mg/mL into an active inflammatory acne papule or nodule, as this concentration is specifically recommended by the American Academy of Dermatology for nodular acne treatment. 1, 2, 3
Recommended Concentration and Dosing
The standard concentration for acne is triamcinolone acetonide 10 mg/mL, which can be used undiluted or diluted with sterile normal saline to 5 mg/mL or 3.3 mg/mL. 1, 2, 3
The injection volume should be 0.05-0.1 mL per lesion, producing a visible papule approximately 0.5 cm in diameter. 2, 3
Lower concentrations (2.5-5 mg/mL) are commonly used in clinical practice to minimize adverse effects, with 2.5 mg/mL being the most frequently reported concentration among dermatologists (52.5% of practitioners). 4
Proper Indications
This treatment is indicated specifically for:
- Large, painful inflammatory nodules or cysts at risk for scarring 1, 2, 3
- Occasional stubborn individual cystic lesions resistant to other therapies 2, 3
- Situations requiring rapid reduction in inflammation and pain (48-72 hours) 2, 3
Critical limitation: This is an adjuvant therapy only, not effective for multiple lesions or as primary treatment. 1, 2, 3
Injection Technique
Inject intradermally into the center of the lesion - 61.6% of dermatologists inject into the center of the lesion. 4
Proper placement is confirmed by formation of a visible papule with blanching. 3
The injection depth should be just beneath the dermis in the upper subcutis, avoiding superficial injection which dramatically increases atrophy risk. 2
Adverse Effects and Risk Mitigation
Local complications occur but can be minimized:
Skin atrophy occurs in 44% of patients when using higher concentrations, but using 10 mg/mL or lower significantly reduces this risk. 2
When atrophy does occur, it typically lasts over 6 months (48.4% of cases). 4
Hypopigmentation, pigmentary changes, and telangiectasias can develop. 2, 3
To minimize adverse events:
Use the lowest effective concentration and volume - decreasing from 40 mg/mL to 10 mg/mL or diluting to 5 mg/mL significantly reduces atrophy risk. 2
Avoid injecting too superficially, which increases atrophy and pigmentary changes. 2
Apply sparingly to skin folds and intertriginous areas. 3
Contraindications
Do not inject if:
- Active infection is present at the injection site 3
- Patient has previous hypersensitivity to triamcinolone 3
- Active tuberculosis or systemic fungal infection exists (for large injections) 3
Clinical Context
Most acne nodules flatten within 48-72 hours after injection. 2, 3
This treatment should be reserved for occasional or particularly stubborn cystic lesions, not used for multiple lesions. 2, 3
Patients with severe nodular acne, significant psychosocial burden, or scarring should be considered candidates for isotretinoin as definitive therapy rather than relying on repeated intralesional injections. 1, 3
Always use intralesional corticosteroids in conjunction with comprehensive topical therapy (retinoids, benzoyl peroxide) and systemic treatments when appropriate. 1, 3
Common Pitfalls to Avoid
Do not use this as primary treatment for multiple acne lesions - it is ineffective as monotherapy and increases adverse effect risk. 2, 5
Do not inject excessively or use concentrations higher than 10 mg/mL for acne - this dramatically increases adverse effect risk without improving efficacy. 2
Do not inject superficially - this increases atrophy and pigmentary changes. 2
Counsel patients on potential hypopigmentation and atrophy before injection - 50.5% of dermatologists do this routinely. 4