Simple objective measurement of the cutaneous delayed-type hypersensitivity reaction to tuberculin using spectrophotometry

Purified protein derivatives of tuberculin--past, present, and future

The tuberculin skin test, which involves monitoring the immune reaction to an injection of purified protein derivative (PPD), has been the most widely used method for detecting infection with Mycobacterium tuberculosis since its development in 1930s. Until recently, the molecular composition of PPD was unknown. This thwarted the discovery of improved skin testing reagents and drastically hindered efforts to define the mechanism of action. Proteomic evaluation of PPD combined with a detailed analysis in the guinea pig model of tuberculosis led to further definition of the molecular composition of PPD. This communication reviews the history and current status of PPD, in addition to describing candidate next-generation PPD reagents, based on the use of an individual protein or protein cocktails.

Subepidermal moisture predicts erythema and stage 1 pressure ulcers in nursing home residents: a pilot study

OBJECTIVES

To examine the relationship between a measure of subepidermal moisture (SEM) and visual skin assessment (VSA) of erythema and Stage 1 pressure ulcers (PUs) performed a week later in nursing home (NH) residents.

DESIGN

Descriptive, cohort study.

SETTING

Two NHs.

PARTICIPANTS

Thirty-five residents.

METHODS

Concurrent VSAs and SEM readings were obtained at the sacrum, right and left trochanters, buttocks, and ischial tuberosities weekly for 52 weeks. SEM was measured using a handheld dermal phase meter, with higher readings indicating greater SEM (range 0-999 dermal phase units [DPUs]). VSA was rated as normal, erythema/Stage 1 PU, or Stage 2+PU. SEM was modeled as a predictor of VSA of erythema and PUs 1 week later (controlling for clustering), with concurrent moisture, Braden Scale PU risk status, anatomic site, and ethnicity as covariates.

RESULTS

Participants had a mean age of 84.7, 83% were female, and 80% were non-Hispanic white. SEM measures were lowest for normal skin (97+/-122 DPU), higher for erythema/Stage 1 PUs (192+/-188 DPU), and highest for Stage 2+PUs (569+/-320 DPU) across all sites (all P<.001). SEM was responsive to changes in VSA, and higher SEM predicted greater likelihood of erythema/Stage 1 PU the next week (odds ratio=1.26 for every 100-DPU increase in SEM, P=.04).

CONCLUSION

SEM measures are associated with concurrent erythema and PUs and future (1 week later) development of erythema/Stage 1 PUs. SEM may assist in predicting early PU damage, allowing for earlier intervention to prevent skin damage.

Photorejuvenation by Intense Pulsed Light with Objective Measurement of Skin Color in Japanese Patients

BACKGROUND AND OBJECTIVES

This study had two objectives: subjective evaluation of overall skin rejuvenation effects of relatively short-wavelength intense pulsed light (IPL) and objective changes in basic skin tone as measured by a spectrophotometer.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-five women selected at random received a series of three IPL treatments. Efficacy was evaluated over a 3-month follow-up period. Concurrently, a spectrophotometer was used to measure "lightness" (L(*)) to quantify the lightening effect changes to pretreatment and posttreatment basic skin tone.

RESULTS

Subjective improvement of 50% or more was seen in 18 of 25 patients for pigmentation. One patient showed exacerbation of latent epidermal melasma as a complication. In the spectrophotometric analysis, the mean value of L(*) increased from a baseline value of 60.86 to 63.22, at 3-month follow-up period, with statistical significance.

CONCLUSION

IPL skin rejuvenation using relatively shorter wavelengths and pulse widths brought about significant macroscopic and quantitative improvements, especially in the treatment of epidermal pigmentation and improvement of basic skin tone.

Objective evaluation for severity of atopic dermatitis by morphologic study of skin surface contours

BACKGROUND/AIMS

Wide variation in outcome methodology can make the interpretation of patient outcomes confusing and the comparison of the results of different studies almost impossible. It is important to objectively measure and record the severity of atopic dermatitis (AD) for routine clinical practice and research. The aim of this study was to evaluate whether morphologic study of skin surface contours might be helpful to objectively quantify the severity of AD.

METHODS

Thirty atopic patients (12 females, 18 males) participated in this study. Moisturizer was applied twice daily for 2 weeks. Bioengineering methods such as D-Squame, corneometer, evaporimeter, and spectrophotometer were measured at the start of the study and after 1 week and 2 weeks. In addition, we assessed moisturizer effects after 3 h of moisturizer application.The stereoimage optical topometer (SOT) based on a new concept of stereoimage was applied for this study. We compared SOT, other bioengineering methods, and the severity scoring of atopic dermatitis (SCORAD) index.

RESULTS

After 3 h of application with moisturizer, the results measured by SOT, conventional optical profilometer (COP), D-Squame, and corneometer showed significant differences (P<0.05). After 1 and 2 weeks, there were significant changes in the results measured by SOT, COP, D-Squame, corneometer, spectrophotometer, and SCORAD index. We observed a significant correlation between bioengineering methods and the SCORAD index (P<0.05).

CONCLUSION

These data indicate that morphologic study of skin surface contours are useful in evaluating of AD severity. If we would combine methods to evaluate the physiologic changes and those such as SOT to measure the morphological changes of skin surface, we could evaluate more objectively and quantitatively the severity of AD.