[A case of corticosteroid allergy]

Area of Science:

• Dermatology
• Allergology
• Clinical Immunology

Background:

• Severe atopic dermatitis often requires long-term management with topical corticosteroids.
• Corticosteroid-induced allergic contact dermatitis is a known but often underdiagnosed complication.
• The classification of corticosteroids is crucial for understanding cross-reactivity patterns.

Observation:

• A 42-year-old female with a history of severe atopic dermatitis presented with erythema and edema post-intra-articular steroid injection.
• The patient had used steroid-containing ointments for several decades.
• Symptoms localized to the injection site, suggesting a delayed hypersensitivity reaction.

Findings:

• Allergological assessment identified a type-IV hypersensitivity to group D2 corticosteroids.
• Group D2 corticosteroids are characterized by specific structural features (no C16 methyl, C17 ester, possible C21 side chain).
• This case highlights a specific corticosteroid allergy within the broader spectrum of steroid hypersensitivity.

Implications:

• Clinicians should consider allergic contact dermatitis in patients with atopic dermatitis experiencing treatment failure or worsening symptoms.
• Accurate corticosteroid classification is vital for identifying potential allergens and predicting cross-reactivity.
• Awareness of corticosteroid allergy prevalence (1.1%-3.1% in Germany) is important for patient management and diagnosis.