Does non-immunologic mast cell mediator release/activation elicit a late cutaneous response?

Area of Science:

• Dermatology
• Allergology
• Immunology

Background:

• Mast cell mediators are crucial in allergic skin reactions.
• Understanding the progression from early to late cutaneous responses is key to diagnosing and treating allergic conditions.
• Chronic urticaria and angioedema represent distinct allergic inflammatory pathways.

Purpose of the Study:

• To investigate the development of late cutaneous responses following early wheal reactions induced by codeine.
• To compare the reactions in normal subjects, patients with chronic urticaria, and patients with angioedema requiring steroid therapy.
• To explore the role of histamine and the effect of prednisone on these responses.

Main Methods:

• Intracutaneous injections of codeine and histamine were administered.
• Early and late cutaneous responses (wheal and flare) were monitored and measured.
• Patient groups included healthy volunteers, individuals with chronic urticaria, and those with angioedema on steroid therapy.

Main Results:

• Early wheal responses to codeine did not typically progress to late responses in normal subjects and chronic urticaria patients.
• Patients with angioedema on steroids exhibited small late responses to both codeine and histamine, unlike normal subjects.
• Ingested prednisone inhibited these small late responses in the angioedema group.

Conclusions:

• A sufficient early mast cell mediator release does not guarantee a late cutaneous response.
• Patients with angioedema on steroids possess a unique susceptibility to prolonged histamine-induced skin responses.
• Prednisone's efficacy in treating angioedema may involve the inhibition of these prolonged inflammatory responses.