'Pseudomorphoea': a side effect of subcutaneous corticosteroid injection.

Area of Science:

• Dermatology
• Endocrinology
• Pharmacology

Background:

• Corticosteroids are widely used for their anti-inflammatory properties.
• Long-acting corticosteroid preparations are often administered via intramuscular injection.
• The deltoid region is a common site for vaccine and medication injections.

Observation:

• Three patients developed localized skin thinning (cutaneous atrophy) in the upper arm.
• The atrophy occurred at the site of a single intramuscular injection.
• The injections administered were of a long-acting corticosteroid preparation into the deltoid muscle.

Findings:

• Intramuscular corticosteroid injections can lead to localized cutaneous atrophy.
• The deltoid injection site appears susceptible to this specific adverse effect.
• This finding suggests a potential localized tissue reaction to the corticosteroid formulation.

Implications:

• Clinicians should be aware of the risk of cutaneous atrophy following deltoid corticosteroid injections.
• Patient counseling should include information about potential localized skin side effects.
• Further research may be warranted to elucidate the mechanism and incidence of this adverse event.