Intralesional Corticosteroid Injections for Hypertrophic Scars

Standard Intralesional Corticosteroid Protocol

The American Academy of Dermatology recommends triamcinolone acetonide 40 mg/mL for intralesional injections into hypertrophic scars, with treatment frequency ranging from once weekly to monthly depending on scar response, avoiding injection into active infections or areas with previous hypersensitivity to triamcinolone 1
Triamcinolone acetonide 40 mg/mL is the standard concentration for hypertrophic scars, as indicated by the American Academy of Dermatology 1
The higher concentration (40 mg/mL) is specifically indicated for hypertrophic scars and keloids, according to the American Academy of Dermatology 1
Injecting directly into the hypertrophic scar tissue intralesionally is recommended, as per the American Academy of Dermatology 1
Avoid injecting into healthy surrounding tissue, as advised by the Mayo Clinic 2
Marking the borders of the scar with skin-safe single-use markers before treatment is suggested by the Mayo Clinic 2
Using an appropriate needle gauge (typically 25-27 gauge) is recommended, based on injection principles from the European Journal of Nuclear Medicine and Molecular Imaging 3

Most hypertrophic scars flatten within 48 to 72 hours after injection, as reported by the American Academy of Dermatology 1
Monitoring and recording scar evolution at each visit, potentially using photography with patient consent, is recommended by the Mayo Clinic 2

Active infections at the injection site, previous hypersensitivity to triamcinolone, active tuberculosis or systemic fungal infection, extensive plaque psoriasis, pustular psoriasis, or erythrodermic psoriasis, active peptic ulcer disease, uncontrolled diabetes, heart failure, or severe hypertension, and severe depression or psychosis are strict contraindications for intralesional corticosteroid injection, as stated by the American Academy of Dermatology 1

Local complications from intralesional corticosteroids include atrophy, pigmentary changes, telangiectasias, hypertrichosis, and steroid acne, as reported by the American Academy of Dermatology 1
Contact allergic dermatitis from benzyl alcohol preservative is a potential adverse effect, as noted by the Mayo Clinic 2
Sterile abscess formation is a possible complication, according to the European Journal of Nuclear Medicine and Molecular Imaging 3
Repeated injections can suppress the hypothalamic-pituitary-adrenal axis, as warned by the American Academy of Dermatology and the Mayo Clinic [1] [2]
Rare anaphylaxis, angioedema, and urticaria are potential systemic concerns, as reported by the American Academy of Dermatology 1

Checking injection sites at every regular visit, or at least annually, and recording scar evolution using photography (with consent), body maps with size/shape/texture descriptors, or transparent graduated recording sheets are recommended by the Mayo Clinic 2

This treatment is efficacious for occasional or particularly stubborn lesions but is not an effective strategy for patients with multiple widespread lesions, as noted by the American Academy of Dermatology 1