Researchers ID underlying cause of atopic dermatitis

Staphylococci bacteria on the skin’s surface can produce a biofilm that occludes the sweat ducts, which results in atopic dermatitis and eczema, according to results of a recent study.

Investigators with Drexel University College of Medicine, Philadelphia, sought to examine the bacteria responsible for producing biofilms in lesions of atopic dermatitis, and how the immune system responds to the occlusion of sweat ducts by the biofilms.

Study authors analyzed samples from lesional and nonlesional skin swabs taken from 40 patients who had atopic dermatitis. Each of the samples affected with atopic dermatitis had drug-resistant staphylococci, which tested posted for biofilm.

“Toll-like receptor 2 was shown to be activated in AD (atopic dermatitis) lesional skin (immediately proximal to the sweat ducts), which likely led to the initiation of proteinase-activated receptor 2-mediated pruritus and MyD88-mediated spongiosis,” study authors wrote.

Staphylococci’s formation of biofilm “almost certainly plays a major role” in blocking sweat ducts, leading to inflammation and itching, according to the study authors.

“We believe the environmental hit in AD relates to staphylococci and their biofilms, which occlude sweat ducts,” they concluded.

The findings were published online Jan. 22 in JAMA Dermatology.