Intralesional Injections

Intralesional steroid injection involves a corticosteroid, which is injected directly into a lesion on or immediately below the skin.

1. What are Intralesional steroids used for?
Intralesional steroid injection may be indicated for the following skin conditions:
a). Alopecia areata.
b). Keloids/hypertrophic scars.
c). Hypertrophic lichen planus.
d). Acne cysts (see Nodulocystic acne).
e). Other localised inflammatory skin diseases.

2. What are the advantages of Intralesional steroids?
Intralesional administration of corticosteroids is used to treat a dermal inflammatory process directly. In contrast to topical steroids, Intralesional steroids:
a). Bypass the barrier of a thickened stratum corneum.
b). Reduce the chance of epidermal atrophy (surface skin thinning).
c). Deliver higher concentrations to the site of the pathology.

3. Contraindications to Intralesional steroid?
a). Intralesional steroids should not be injected at the site of active skin infection e.g., impetigo (school sores) or herpes simplex (cold sores).
b). They must not be used if there is a previous history of corticosteroid hypersensitivity (allergy).

4. Administration of Intralesional steroid?
Intralesional triamcinolone is injected directly into the skin lesion using a fine needle after cleaning the site of injection with alcohol or antiseptic solution. The injection should be intradermal, not subcutaneous, to avoid causing a dent in the skin.
The initial dose per injection site will vary depending on the lesion being treated. It can be repeated every 4 to 8 weeks.

5. What are the Side effects arising at the site of Intralesional steroid injection?
Side effects and risks of Intralesional therapies may be following which are usually self-limiting:
a). Pain, bleeding, bruising.
b). Infection.
c). Contact allergic dermatitis due to the preservative, benzyl alcohol.
d). Impaired wound healing.
e). Sterile abscess, sometimes requiring surgical drainage.