Tape stripping – a painless way to distinguish AD and psoriasis?

A recent trial explored a new diagnostic approach to discriminate between atopic dermatitis (AD) and psoriasis without leaving scars. The discovery of specific molecular profiles of the 2 diseases by RNA analyses of the tape-stripping samples may be of substantial future value [1].

When evaluating unclear inflammatory skin lesions, biopsies with histopathological investigation are still the gold standard. However, these invasive procedures can cause pain and lead to scarring, which can be especially problematic in children. Furthermore, research with therapeutic agents in children would be easier if biopsies would not be necessary. Dr Robert Bissonnette (Innovaderm Research, Canada) and his fellow researchers intended to create a sensitive yet non-invasive diagnostic tool by using tape stripping to study the genomic profile of AD and psoriasis for a skin biomarker approach to diagnosis.

Enrolled in the trial were 60 participants: 20 patients with psoriasis, 20 patients with AD, and 20 healthy volunteers. After collecting samples by tape stripping, the RNA extracted from theses samples were investigated by quantitative reverse transcription polymerase chain reaction (qRT-PCR) to examine immune and barrier genes.

As predicted, the procedure of tape stripping did not cause any safety issues. With a detection rate of 100%, 99/100 assessed skin biomarkers were detected. Remarkable differences were found in the expression profiles of the 2 diseases. The samples from AD patients contained higher levels of Th2 products indicated by gene upregulation, including IL-13 (fold-change 169.0), IL-4 (fold-change 7.7), IL-31 (fold-change 4.3), and CCL17 (fold-change 4.3). Furthermore, markers were found for Th2 activation like ICOS (fold-change 16.9) and CCR4 (fold-change 5.5; P<0.05), which were increased in the AD specimens. The psoriasis samples on the other hand, contained elevated expression of Th1 products like IFNG (fold-change 51.1). Furthermore, Th17 products like IL-17A (fold-change 175.0) and NOS2 (fold-change 10,200; P<0.001) were augmented in psoriasis. NOS2 was seen as a potential disease classifier by the investigators as there was 100% accuracy in differentiation of expression between psoriasis and AD.

The researchers concluded that tape stripping permitted a clear and highly sensitive distinction between AD and psoriasis. Further studies are needed to evaluate this new technique to track skin biomarker changes for their possible use in clinical trials.

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1. Bissonnette R, et al. Late-breaking abstract, AAD Virtual Meeting Experience, 12-14 June 2020.

Posted on 6 August 20205 January 2021