Psoriasis lesions in the study participants contained large numbers of so-called Th1 and Th17 cells, whereas eczema lesions had higher amounts of Th2 and Th22 cells. The researchers expanded their testing to include five patients with psoriasis and skin allergies to nickel -- a much more common combination that prompts an eczema-like reaction -- to confirm a similar T-cell response to psoriasis.
The study also found that all eczema lesions, but none in psoriasis, harbored Staphylococcus aureus bacteria, confirming that T-cells in psoriasis appear to prompt an innate immune response that's different from what is seen in eczema.
Dr. Jerry Bagel, a spokesman for the National Psoriasis Foundation and associate clinical professor of dermatology at Columbia University in New York City, said the research indicates that eczema and psoriasis "are clearly distinct entities, but there is some crossover immunologically."
If scientists could determine which antigens stimulate each condition -- a job that would likely take years -- they might find new ways to stop the disorders from developing in predisposed people, Bagel and Day agreed.
Current psoriasis treatments, which include both topical and systemic drugs, aim to suppress the body's immune response and slow down the skin cell growth cycle that leads to its trademark red, scaly plaques. Eczema treatments can involve both medications and lifestyle changes that cut itching, inflammation and worsening of the condition.
But, perhaps in the future, "they could have more direct testing to see if patients have an immune system alteration," Day said. "The more we understand the pathways and how the immune system responds to insults from the external world . . . we can adjust steps along the way, or medications that minimize side effects and maximize safety."
Find out more about eczema and psoriasis at the
All rights reserved