[Paradoxical cutaneous reactions associated with tocilizumab therapy]

Area of Science:

• Immunodermatology
• Rheumatology
• Pharmacology

Background:

• Tocilizumab (TCZ), an IL-6 receptor antagonist, treats various inflammatory conditions like rheumatoid arthritis and juvenile idiopathic arthritis.
• Biologic therapies including anti-TNFα, rituximab, abatacept, and TCZ are associated with paradoxical cutaneous reactions, notably palmoplantar psoriasis.
• These reactions present as a significant side effect in patients undergoing treatment with advanced immunomodulatory agents.

Observation:

• A 47-year-old woman with psoriatic arthritis experienced a paradoxical palmoplantar eruption.
• The eruption initially appeared during anti-TNFα therapy and subsequently recurred while on tocilizumab treatment.
• This case highlights a specific presentation of drug-induced skin reactions in patients with autoimmune diseases.

Findings:

• Tocilizumab, like other biologics, can induce paradoxical palmoplantar psoriasis in patients with psoriatic arthritis.
• The patient's history of psoriatic arthritis and prior anti-TNFα treatment are key factors in this observation.
• The recurrence of the eruption under a different biologic agent suggests a potential class effect or individual susceptibility.

Implications:

• The precise mechanisms driving these paradoxical skin reactions remain to be elucidated.
• The potential for lesion relapse with certain biological agents necessitates vigilant monitoring and management strategies.
• Further research is warranted to understand the immunopathogenesis and predict susceptibility to these adverse cutaneous events.