Natural skin surface pH is on average below 5, which is beneficial for its resident flora

Variable skin pH values are being reported in literature, all in the acidic range but with a broad range from pH 4.0 to 7.0. In a multicentre study (N = 330), we have assessed the skin surface pH of the volar forearm before and after refraining from showering and cosmetic product application for 24 h. The average pH dropped from 5.12 +/- 0.56 to 4.93 +/- 0.45. On the basis of this pH drop, it is estimated that the 'natural' skin surface pH is on average 4.7, i.e. below 5. This is in line with existing literature, where a relatively large number of reports (c. 50%) actually describes pH values below 5.0; this is in contrast to the general assumption, that skin surface pH is on average between 5.0 and 6.0. Not only prior use of cosmetic products, especially soaps, have profound influence on skin surface pH, but the use of plain tap water, in Europe with a pH value generally around 8.0, will increase skin pH up to 6 h after application before returning to its 'natural' value of on average below 5.0. It is demonstrated that skin with pH values below 5.0 is in a better condition than skin with pH values above 5.0, as shown by measuring the biophysical parameters of barrier function, moisturization and scaling. The effect of pH on adhesion of resident skin microflora was also assessed; an acid skin pH (4-4.5) keeps the resident bacterial flora attached to the skin, whereas an alkaline pH (8-9) promotes the dispersal from the skin.

Acoustic streaming: a new technique for assessing adnexal cysts

OBJECTIVES

To determine whether acoustic streaming has clinical value in the differentiation between various ovarian and adnexal cysts.

METHODS

We assessed 29 adnexal cysts, for which pathological diagnosis was available, for the presence of acoustic streaming during B-mode and color sonographic evaluation.

RESULTS

Acoustic streaming was detected in 15 (52%) of the cysts. The most common cyst, endometrioma (n = 7), did not exhibit acoustic streaming in any case, while of the remaining 22 cysts, 15 exhibited acoustic streaming (P = 0.0017). Dermoid cysts exhibited acoustic streaming in two of six (33%) cases. In addition acoustic streaming was noted in two of two (100%) hemorrhagic cysts, eight of ten (80%) cystadenomas, two of three (67%) malignant cysts and in the one abscess.

CONCLUSIONS

Acoustic streaming is the first sonographic feature that may be able to completely exclude endometrioma as a possible diagnosis for an adnexal cyst.