Triamcinolone Acetonide (TA) Intralesional Injection - Alopecia Areata & Keloid

PART 1: ALOPECIA AREATA

Fig. Alopecia areata with multiple circumscribed patches (Andrews' Diseases of the Skin)

Indication for Injection

Strength (Concentration)

Key caution: Large volumes and higher concentrations carry a greater risk of local skin atrophy. Injecting under significant pressure or with a small-bore syringe increases the risk of retinal artery embolization (a rare but serious complication) - this is particularly relevant near the periorbital area.

Procedure - Step by Step

1. Patient selection: Localized patchy alopecia, cosmetically significant sites (frontal hairline, eyebrow, beard). Not first-line for alopecia totalis/universalis.
2. Preparation: Draw up triamcinolone acetonide suspension (dilute commercial 40 mg/mL stock with normal saline or lidocaine to target concentration of 2-10 mg/mL).
3. Syringe and needle: Use a 1 mL tuberculin syringe with a 30-gauge needle (short).
4. Injection plane: Deliver intradermally or in the superficial subcutaneous tissue - NOT deep subcutaneous (to avoid atrophy of deeper tissues and systemic spread).
5. Technique: Multiple small blebs are raised across the patch, spaced ~1 cm apart. Each injection site receives approximately 0.05-0.1 mL.
6. Dose per site: Limit to approximately 1 mg per treatment site (i.e., 0.1 mL of a 10 mg/mL suspension per point) to minimize local atrophy.
7. Total session dose: Keep total dose per session within safe limits to minimize HPA axis suppression.
8. Injection interval: Repeat every 4-6 weeks as needed; hair regrowth is typically seen after 4-8 weeks.

Expected Response

• Regrowth is typically observed in cosmetically significant patches; patchy disease responds best.
• Ophiasic alopecia areata tends NOT to respond.
• High rate of spontaneous recovery must be factored into evaluating treatment success.

Adverse Effects

• Local skin atrophy (most common)
• Hypopigmentation from lymphatic spread of corticosteroid
• Telangiectasia
• Retinal artery embolization (rare, especially near periorbital region)
• HPA axis suppression with excessive use

PART 2: KELOID

Fig. Keloid of earlobe - clinical appearance and radiofrequency excision steps (Pfenninger & Fowler's Procedures for Primary Care)

Background

Strength (Concentration)

The higher starting dose of 40 mg/mL is used for keloids because they are dense, fibrous, and highly resistant - unlike alopecia areata which requires much lower concentrations.

Procedure - Step by Step

1. Anesthesia: For large/painful keloids, local anesthesia with lidocaine may be injected first. A dilute steroid can be included in the anesthetic mixture.
2. Syringe and needle: Use a 1 mL tuberculin Luer syringe with a 30-gauge needle. Because keloids are very firm and dense, significant force is needed - use a Luer-lock syringe to prevent the needle from popping off.
3. Technique: Insert the needle directly into the substance of the keloid (intralesional). Inject triamcinolone suspension into various parts of the lesion, distributing it throughout.
4. Blanching endpoint: Inject until the lesion blanches white (indicates adequate tissue saturation and even distribution).
5. Injection interval: Repeat at 6-8 week intervals as required, until the keloid flattens and pruritus ceases.
6. Combination therapy: TA 40 mg/mL may be combined with 5-fluorouracil (5-FU 50 mg/mL mixed with TA 1 mg/mL) for refractory keloids, or combined with long-pulsed Nd:YAG laser, verapamil, or methotrexate.

For Old/Established Keloids

• Excise the keloid first using lidocaine with triamcinolone as the local anesthetic.
• Follow immediately with intralesional TA injections at the wound site.
• Repeat injections at 2-week intervals post-excision.
• Can be combined with postoperative irradiation or topical imiquimod.
• Monitor for recurrence every 3 months for 1-2 years.

Expected Response

• Flattening of the keloid and cessation of itching are reliably achieved.
• The lesion will NOT become narrower with injection alone.
• Hyperpigmentation generally persists.
• Young keloids respond better than old established ones.

Adverse Effects

COMPARISON SUMMARY

• Andrews' Diseases of the Skin, Clinical Dermatology - Keloid section & Alopecia Areata section
• Fitzpatrick's Dermatology Vol. 1 - Scar formation section
• Pfenninger & Fowler's Procedures for Primary Care, 3rd ed. - Hypertrophic scars and keloids chapter
• Katzung's Basic and Clinical Pharmacology, 16th ed. - Intralesional corticosteroids section