What is a Kenalog (triamcinolone acetonide) injection?

What is a Kenalog Shot?

Kenalog is the brand name for triamcinolone acetonide injectable suspension, a synthetic glucocorticoid (corticosteroid) with potent anti-inflammatory properties that is administered by injection into muscles, joints, soft tissues, or directly into skin lesions. 1

Formulation and Composition

• Each mL of Kenalog contains 40 mg of triamcinolone acetonide suspended in an aqueous vehicle with benzyl alcohol (0.99%) as a preservative, carboxymethylcellulose sodium, and polysorbate 80. 1
• The formulation is specifically designed for intramuscular and intra-articular use only—it is not for intradermal injection. 1
• The suspension appears as an off-white colored sterile preparation with a pH adjusted to 5.0–7.5. 1

Primary Clinical Uses

Intramuscular Administration

• The FDA approves intramuscular Kenalog for severe allergic conditions (asthma, atopic dermatitis, contact dermatitis, drug hypersensitivity reactions, allergic rhinitis), severe dermatologic diseases (pemphigus, Stevens-Johnson syndrome, mycosis fungoides), endocrine disorders, gastrointestinal diseases (regional enteritis, ulcerative colitis), hematologic disorders, rheumatic disorders (acute gout, rheumatoid arthritis), and various other systemic inflammatory conditions when oral therapy is not feasible. 1

Intra-Articular and Soft Tissue Injection

• The FDA approves intra-articular Kenalog as adjunctive therapy for acute gouty arthritis, acute and subacute bursitis, acute nonspecific tenosynovitis, epicondylitis, rheumatoid arthritis, and synovitis of osteoarthritis. 1
• For juvenile idiopathic arthritis, the American College of Rheumatology strongly recommends intra-articular glucocorticoid injections, with triamcinolone hexacetonide being the preferred agent over triamcinolone acetonide due to more durable clinical responses. 2

Intralesional Injection (Dermatologic)

• The American Academy of Dermatology recommends intralesional triamcinolone acetonide for nodular acne (10 mg/mL, may be diluted to 5 or 3.3 mg/mL), acne keloidalis (10 mg/mL), hypertrophic scars and keloids (40 mg/mL), psoriasis plaques (up to 20 mg/mL), and nail psoriasis (5-10 mg/mL). 2
• For alopecia areata, the British Association of Dermatologists recommends 5-10 mg/mL concentration injected just beneath the dermis in the upper subcutis, with 0.05-0.1 mL per injection site producing hair regrowth covering approximately 0.5 cm diameter. 2

Mechanism and Duration of Action

• Triamcinolone acetonide exhibits unique pharmacokinetics when injected intramuscularly, with prolonged anti-inflammatory effects lasting weeks to months due to low solubility in blood, slow absorption from the injection site, and low renal clearance. 3
• The acetonide ester formulation creates a depot effect at the injection site, allowing sustained release and extended therapeutic action compared to other corticosteroids. 3

Common Dosing Protocols

Dermatologic Conditions

• For keloids and hypertrophic scars, inject 40 mg/mL concentration just beneath the dermis in the upper subcutis (not into the lesion itself), using 0.05-0.1 mL per site, repeated every 3-4 weeks until flattening occurs. 2, 4
• For facial keloids or sensitive areas, use lower concentrations (5-10 mg/mL) to minimize atrophy risk. 4

Joint and Soft Tissue Injections

• For shoulder pain, 40 mg of triamcinolone acetonide is typically administered into the glenohumeral joint or subacromial space. 2
• For acute gout involving 1-2 large joints, the American College of Rheumatology recommends intra-articular corticosteroids, with a single injection often sufficient. 2

Critical Safety Considerations and Contraindications

Absolute Contraindications

• Do not inject at sites with active infection (impetigo, herpes), in patients with previous hypersensitivity to triamcinolone, or in those with active tuberculosis or systemic fungal infections. 2, 4

High-Risk Situations Requiring Caution

• Exercise caution in patients with uncontrolled diabetes, heart failure, or severe hypertension. 2, 4
• Facial and intertriginous areas carry higher risk for adverse effects including atrophy, telangiectasias, and pigmentary changes. 2, 5
• Repeated injections can suppress the hypothalamic-pituitary-adrenal axis. 2

Common Adverse Effects

• Skin atrophy is the most consistently reported local adverse effect, particularly with higher concentrations or repeated injections. 2, 5
• Other local effects include pigmentary changes, telangiectasias, hypertrichosis, and folliculitis. 2, 5
• Granulomatous foreign body reactions to intralesional triamcinolone have been reported, though rarely. 6

Important Clinical Pitfalls to Avoid

• Never use high-potency formulations on facial skin—the thin facial epidermis is especially vulnerable to steroid-induced atrophy. 5
• Always inject just beneath the dermis in the upper subcutis for intralesional therapy, avoiding deeper subcutaneous fat or the lesion substance itself. 2, 4
• Do not exceed 150 mg total dose per injection session. 2
• For esophageal stricture injections, use a 4 mm-long, 23-gauge needle and leave in place for at least 1 minute to minimize leakage. 2