Immunodermatology Primer

Immunodermatology Primer presented by Adam Friedman MD

Toll-like receptor 2 in the pilosebaceous unit is overactive in response to C. acnes colonization, resulting in the inflammatory cascade seen in all types of acne as well as collagen breakdown that leads to scarring. Isotretinoin and topical retinoids down-regulate TLR-2.

In atopic dermatitis patients, toll-like receptors are defective, thus they lack sufficient cutaneous antimicrobial peptides to respond to pathogens and have a higher risk for secondary infection. Conversely, psoriasis patients have more antimicrobial peptides and are less likely to get infections.

Drug reactions tend to worsen in severity and in a shorter time period to onset with subsequent exposures following the initial reaction due to IgG memory.