Factors which influence late cutaneous allergic responses

Area of Science:

• Immunology
• Dermatology
• Allergy Research

Background:

• Allergic reactions manifest as immediate wheal-and-flare responses.
• Late cutaneous allergic responses (LCAR) are a less understood component of allergic skin reactions.
• The role of neurogenic inflammation in LCAR is not fully elucidated.

Purpose of the Study:

• To investigate the relationship between allergen dose and the development of LCAR.
• To compare LCAR induced by different allergens and anti-IgE.
• To determine the influence of nerve function on LCAR.

Main Methods:

• Intracutaneous injections of ragweed antigen E, grass pollen extract, and anti-IgE in human subjects.
• Comparison of prick tests versus intracutaneous injections for LCAR induction.
• Assessment of LCAR in denervated skin and after local anesthesia.

Main Results:

• Increased doses of allergens and anti-IgE led to larger early responses and more frequent, larger LCAR.
• LCAR were a common sequel to intense early allergic skin reactions.
• LCAR induced by Aspergillus fumigatus allergen were comparable to those induced by other allergens and anti-IgE.
• Prick tests and intracutaneous injections showed similar tendencies to induce LCAR for comparable early responses.
• Denervation and local anesthesia abolished the early flare but did not prevent LCAR.

Conclusions:

• LCAR are a consistent feature of significant allergic skin reactions.
• The development of LCAR is independent of the neurogenic flare component of the immediate response.
• These findings contribute to understanding the pathophysiology of allergic skin inflammation.