Will a 0.4 cc kenalog (triamcinolone) steroid injection for hypertrophic scars on inframammary incisions have any effects on a patient who has recently undergone rhinoplasty and is taking tirzepatide?

Intralesional Triamcinolone for Hypertrophic Scars on Inframammary Incisions

Yes, the 0.4 cc kenalog (triamcinolone) injection will have significant therapeutic effects on the hypertrophic scars, with expected flattening within 48-72 hours, though you must monitor for potential adverse effects including skin atrophy, depigmentation, and depression at the injection site. 1, 2

Expected Therapeutic Effects

Rapid symptom improvement will occur with most hypertrophic scars flattening within 48-72 hours after intralesional triamcinolone injection, providing both reduction in inflammation and pain relief. 1 This rapid response makes intralesional steroids particularly effective for hypertrophic scars that are at risk for further scarring or causing significant symptoms. 1

The mechanism involves:

• Suppression of fibroblast proliferation and abnormal collagen production 3
• Reduction of inflammatory mediators in the scar tissue 4
• Reorientation of collagen bundles within the scar 5

Critical Adverse Effects to Monitor

Local tissue atrophy is a consistent side effect that you should specifically counsel the patient about and monitor for at follow-up visits. 1, 6 The 0.4 cc volume you administered requires careful observation for:

• Depression at the injection site - This can occur when injection is too deep or volume is excessive, with steroid crystals depositing in normal tissue 2
• Linear depigmentation and atrophy - An extremely rare but documented complication where steroid crystals are absorbed along lymphatic vessels, creating radiating linear patterns of skin changes that may not improve even after 1 year of topical treatment 2
• Hypopigmentation and pigmentary changes - Common adverse effects that patients should be warned about 1
• Telangiectasias - Can develop at standard concentrations 6

Dosing Considerations for Your Case

The American Academy of Dermatology recommends triamcinolone acetonide 10 mg/mL for scar treatment, which may be diluted to 5 mg/mL or 3.3 mg/mL. 1 Using lower concentrations and smaller volumes minimizes complications. 1 Your 0.4 cc injection volume is reasonable, but the concentration used matters significantly for risk stratification.

For inframammary scars specifically, the injection depth is critical - strictly intralesional placement is essential, confirmed by visible papule formation with blanching to ensure medication stays within target tissue. 1 The inframammary fold represents an intertriginous area where particular caution is warranted as these areas have higher risk for adverse effects. 1

Interaction Considerations

Regarding the patient's recent rhinoplasty and tirzepatide use:

• No direct contraindication exists for intralesional steroid use in this context 1, 6
• The systemic absorption from 0.4 cc intralesional injection is minimal and unlikely to affect rhinoplasty healing or interact with tirzepatide 7
• However, if doses exceed 4 mg/kg systemically, adrenal suppression can occur 6 - your localized injection is well below this threshold

Follow-Up Protocol

Evaluate the injection site at 2-3 weeks to assess:

• Degree of scar flattening and therapeutic response 4
• Presence of atrophy, depression, or pigmentary changes 2
• Need for repeat injection (if initial response incomplete, a second injection at 4-6 weeks may be considered) 4

A French study of nasal region hypertrophic scars showed complete regression in 10 of 12 patients by day 90 with one or two injections of triamcinolone acetonide 40 mg/mL, though two patients had incomplete regression despite marked improvement. 4 This suggests your patient has excellent odds of significant improvement, but complete resolution is not guaranteed.

Advise the patient to avoid direct sunlight and heavily scented products for 24 hours following the injection. 1