Background: Progressive macular hypomelanosis (PMH) is a dermatosis of unknown etiology. It has been concluded that it involves the presence of Propionibacterium acnes, a saprophyte of the pilosebaceous follicles. In our study, we investigated the presence of P. acnes in lesional and non-lesional skin of patients with PMH through quantitative real-time polymerase chain reaction (PCR) and bacterial culture from a skin fragment.
Materials and methods: An observational, exploratory study, with laboratory comparison of lesional (study group) and non-lesional skin (comparison group), in patients with PMH, was carried out with 36 patients, seen in the dermatology outpatient setting at the Oswaldo Cruz University Hospital (OCUH), Recife, Pernambuco, Brazil, between March and May 2008. All patients were submitted to a Wood's lamp examination, mycological research, and biopsies of lesional and non-lesional skin from the back. Skin fragments were submitted to a histopathology test, bacterial culture, and a quantitative real-time PCR test. The program Statistical Package for Social Sciences, version 12.0, was employed for relationship analysis with the Wilcoxon and McNemar tests.
Results: There was a significant predominance of P. acnes on lesional skin, in comparison to non-lesional skin (P<0.001), as demonstrated by culture and quantitative real-time PCR.
Conclusion: Although P. acnes is a saprophyte, the hypothesis may be raised that this microorganism participates in the development of PMH.
© 2011 The International Society of Dermatology.