Effect of pine-tar bath on disease severity in moderate-to-severe childhood eczema: an investigator-blinded, crossover, randomized clinical trial.

Background: Atopic dermatitis (AD) is a chronic inflammatory disease associated with pruritus and sleep loss. Pine-tar has long been used for various chronic skin conditions in which its polycyclic aromatic hydrocarbon (PAH) component is anti-inflammatory and its resin acids antiseptic. The null hypothesis of this trial is that there is no difference in clinical efficacy between a pine-tar product and its vehicle for AD.

Methods: A 3-month, investigator-blinded, crossover, randomized control trial (RCT) was conducted in which each patient was assigned to bathing with pine-tar bath oil for one month and vehicle bath oil for another, with a washout period of 1-month in-between. Acceptability and efficacy of the bath products were measured. Disease severity scores (scoring atopic dermatitis (SCORAD) and patient-oriented eczema measure (POEM), quality of life questionnaires, noninvasive skin biophysiological measurements, blood IgE levels, and S (SA) colonization status were assessed before and following bathing.

Results: Significant improvements were found in total SCORAD ( = .030), POEM ( = .004), SA colonization status ( = .002), and log-transformed IgE level ( = .009) among patients who bathed with pine-tar in the overall RCT study using intention-to-treat analysis. For per protocol analysis, significant improvements were found in total SCORAD ( = .024), objective SCORAD ( = .011), extent ( = .014), intensity ( = .032), pruritus ( = .047), POEM ( = .044), SA colonization status ( = .035), and log-transformed IgE level ( = .028). Acceptability to both bath-oils was good, and no product-related serious adverse events were recorded.

Conclusions: Bathing with pine-tar is an efficacious and recommendable adjuvant practice for AD patients. Disease improvement is associated with reduction of SA and IgE.