New research suggests that the skin microbiota, including C. acnes, may be involved in the development of hypopigmentation in lichen striatus (LS) and may be considered a treatment target to reduce LS duration and hypopigmentation.
These findings come from a paper published in the Journal of the European Academy of Dermatology and Venereology.
In a press release, the authors of the paper note that LS, a skin condition manifesting as linear eruptions following Blaschko's lines on the trunk or limbs of children. It is often accompanied by hypopigmentation—more frequently than other inflammatory skin conditions—and 50% of LS cases have pigment changes that persist for months or years.
They note that Cutibacterium acnes has previously been associated with various skin conditions, including acne vulgaris and post-inflammatory hypopigmentation. This suggested a potential association between C. acnes and the observed skin microbiota of patients with LS with and without hyperpigmentation.
To pursue this hypothesis, researchers collected and analyzed skin samples from 18 patients with LS (11 with hypopigmentation and seven without it) confirmed by biopsy, and assessed any microbial differences in the samples. Despite the diverse stages of LS in patients with hypopigmentation, the investigators observed significant differences in their skin microbiomes. This observation suggested a strong association between LS hypopigmentation and the skin microbiome.
Comparing patients with LS with and without hypopigmentation, the researchers discovered a quadrupled presence (23.26% versus 5.29% of the entire microbiota) of C. acnes in the former.
“Through network analysis between various microbial species found in the skin samples of patients with LS, we observed that C. acnes significantly influenced the bacterial community in hypopigmented LS, holding a central position in relationships with other bacteria. It further strengthens its potential association with LS hypopigmentation pathogenesis,” said study author Dr. Yun Hak Kim, in a press release. Dr. Kim is an Associate Professor from the Department of Anatomy and the Department of Biomedical Informatics, at Pusan National University, South Korea.
The research team additionally identified Malassezia, a genus associated with hypopigmentation in other skin disorders, in abundance among patients with LS with hypopigmentation (0.58% versus 0.31% of the entire microbiota). This finding, in particular the presence of Malassezia restricta, points to a potential link between Malassezia and LS hypopigmentation for targeted future research. Furthermore, Comamonas (15.29% versus 13.45% of the entire microbiota) and Aspergillus (0.30% versus 0.26% of the entire microbiota) were identified as other likely candidates.
Overall, the authors write there is likely a relationship between imbalance in the skin microbiota and LS-associated hypopigmentation. The frequency of Malassezia and C. acnes in hypopigmented LS cases suggests that these two conditions could be novel treatment targets for reducing LS duration as well as hypopigmentation. Patients with LS could thus lead a better quality of life if targeted therapy is focused on these microbiological components.