What is the recommended dose of Depo Medrol (methylprednisolone acetate) for injection into a sebaceous cyst?

Intralesional Corticosteroid Injection for Sebaceous Cysts

For intralesional injection into a sebaceous cyst, use triamcinolone acetonide 10 mg/mL (not Depo-Medrol/methylprednisolone acetate), with a typical injection volume of 0.1-0.3 mL per lesion, which delivers 1-3 mg of triamcinolone per cyst. 1

Why Triamcinolone, Not Depo-Medrol

• Triamcinolone acetonide is the established intralesional corticosteroid for inflammatory skin lesions, including nodular acne and similar cystic structures, as specified in American Academy of Dermatology guidelines 1

• The standard concentration for intralesional use is 10 mg/mL triamcinolone acetonide, which may be diluted with sterile normal saline to 5 or 3.3 mg/mL for more superficial or smaller lesions 1

• Depo-Medrol (methylprednisolone acetate) is not the preferred agent for intralesional dermatologic injections and lacks specific dosing guidance for sebaceous cysts in the literature 2, 3

Specific Dosing Recommendations

• For inflammatory nodular lesions: inject 0.1-0.3 mL of triamcinolone acetonide 10 mg/mL directly into the lesion 1

• This delivers approximately 1-3 mg of active corticosteroid per injection site 1

• The goal is to flatten inflammatory lesions within 48-72 hours 1

Critical Safety Considerations

• Local overdose can result in skin atrophy, pigmentary changes, telangiectasias, and hypertrichosis - these are dose-dependent complications that may be permanent 1

• Do not inject at sites of active infection (impetigo, herpes) or if there is hypersensitivity to triamcinolone 1

• Repeated injections can suppress the hypothalamic-pituitary-adrenal axis, particularly with large volumes or multiple injection sites 1

• Sterile abscess formation is a recognized complication of intralesional corticosteroid injection 1

Clinical Pitfalls to Avoid

• Injecting too superficially causes dermal atrophy - ensure the needle tip is within the cyst cavity or deep dermis 1

• Using concentrations higher than 10 mg/mL increases atrophy risk without improving efficacy for most lesions 1

• This approach is efficacious for occasional or particularly stubborn cystic lesions but not an effective treatment strategy for patients with multiple lesions 1

• True sebaceous cysts (epidermoid or pilar cysts) are typically non-inflammatory and may not respond to intralesional steroids; this technique is most effective for inflamed cysts 4, 5