In a series of mice studies, Dr Raif Geha of Boston Children's Hospital, Massachusetts, and his team identified mechanisms behind inflammation in atopic dermatitis. They also showed that blocking one stage of this process inhibited allergic skin inflammation.
The researchers suggest that reducing the damage caused by scratching may improve outcomes. 'Scratching causes further disruption of an already abnormal skin barrier, allowing cutaneous introduction of antigen,' they said.
Dr Geha's team first demonstrated that scratching in humans, and the experimental analogue of tape stripping in mice, increased neutrophil cell numbers in skin tissue.
'We have identified a critical role for neutrophils in allergic skin inflammation in a mouse model with features of allergic dermatitis,' they said.
The researchers then found that the influx of neutrophil into tape-stripped mouse skin was dependent on production of leukotriene B4 (LTB4) and the activity of LTB4 receptors. They also showed that LTB4 receptor expression was essential for allergic skin inflammation.
Finally, they demonstrated that using a protease inhibitor to block production of LTB4 inhibited inflammation in response to tape-stripping in mice.
The researchers said their findings suggested that LTB4 and its receptors represented 'a potential therapeutic target in allergic dermatitis'.