ABSTRACT
BACKGROUND: The clinical symptoms of facial and truncal acne differ. Skin surface acidity (pH), which is affected by sebum secretions, reflects the different clinical characteristics of the face and trunk. However, no studies have been conducted on truncal sebum production and skin pH. OBJECTIVE: We evaluated the differences and relationship between pH values of the face and trunk. We also evaluated the relationship between pH and the quantity of sebum produced in the trunk. METHODS: A total of 35 female patients clinically diagnosed with truncal acne were included. We measured pH on the face and truncal area using the Skin-pH-Meter PH 905®. We measured truncal sebum secretions using the Sebumeter SM 815®. Statistical analysis was performed to evaluate the correlations and differences between pH and sebum. RESULTS: Facial pH was significantly higher than chest and back pH values. The correlation between pH on the trunk and the face was significant. We used linear regression equations to estimate truncal pH using only measured pH from the chin. There was no significant relationship between truncal sebum secretion and pH. CONCLUSION: This was the first study that evaluated the differences and correlations between facial and truncal pH. We found that facial pH can predict truncal pH. In addition, we conclude that differences in pH and sebum secretion between the face and trunk are one of the reasons for differences in acne symptom at those sites.
ABSTRACT
BACKGROUND: There are few published data on truncal acne because most studies have focused on facial acne. AIMS: The objective of this study was to investigate truncal sebum secretion levels in patients with acne vulgaris and to evaluate the relationship between sebum secretion and the development of acne lesions. METHODS: The sebum casual levels at five different facial sites and ten truncal sites were measured in 35 Korean females with acne using a Sebumeter®. We performed an analysis of the correlation between sebum excretion and acne lesion number. RESULTS: We found that all of the truncal sites analyzed had lower sebum secretion levels than the facial sites. There was no significant correlation between sebum secretion and acne lesions on the trunk. CONCLUSION: Pathogenic factors other than sebum may have a predominant role in the development of truncal acne.
