Psoriasis and Atopic Dermatitis Are Triggered by Responses to Specific Antigens

But our author maintains that intrinsic epithelial abnormalities have a role.

Curiously, psoriasis and atopic dermatitis (AD) rarely occur in the same patient. Psoriasis is driven by Th1 and Th17 helper T cells, while AD is driven by Th2 cells. Investigators studied three patients with both AD and psoriasis. Histologic examination of skin samples from AD and psoriasis lesions showed characteristics of the respective diseases. Psoriasis plaques contained large numbers of Th1 and Th17 cells secreting cytokines γ-interferon and interleukin (IL)-17. The AD samples contained relatively higher numbers of Th2 and Th22 cells secreting IL-4 and IL-22.

Koebner reactions can cause psoriasis in traumatized skin. After a patch test challenge with house-dust antigen, the invading T cells were mostly Th2 cells, and two patients deve…

Reviewing Author

Mark V. Dahl, MD

Disclosures

Consultant / Advisory board Ulthera, Inc.; AuBio LifeSciences, LLC; Paris Therapeutics

Equity Elorac, Inc.; Makucell, Inc.; Paris Therapeutics

Editorial boards UpToDate

Leadership positions in professional societiesNational Rosacea Society (Chairman, Medical Board)