Psoriasis, Atopic Dermatitis, Lyme Disease and Tinea Versicolor: All caused by Microbes but none a Classic Infection

There is a possibility for a role of biofilms in the pathogenesis and chronicity of atopic dermatitis, plaque psoriasis, Lyme disease and tinea versicolor. In atopic dermatitis, plaque psoriasis and Lyme disease, there is evidence to suggest that biofilm-mediated Toll-like-receptor 2 recruitment and activation of the MyD88 pathway is essential. There is also evidence to suggest involvement of the adaptive immune system. Conversely, tinea versicolor does not seem to activate innate nor adaptive immunity, presumably an explanation for its more benign and generally asymptomatic course. Existing evidence for biofilms in the aforementioned diseases is reviewed, and possible links to immune responses, or lack thereof, are postulated. All of this is in sharp contrast with acute microbial infections.