Ingrid Nicander

Skin cancer identification using multifrequency electrical impedance-a potential screening tool

Electrical bio-impedance can be used to assess skin cancers and other cutaneous lesions. The aim of this study was to distinguish skin cancer from benign nevi using multifrequency impedance spectra. Electrical impedance spectra of about 100 skin cancers and 511 benign nevi were measured. Impedance of reference skin was measured ipsi-laterally to the lesions. The impedance relation between lesion and reference skin was used to distinguish the cancers from the nevi. It was found that it is possible to separate malignant melanoma from benign nevi with 75% specificity at 100% sensitivity, and to distinguish nonmelanoma skin cancer from benign nevi with 87% specificity at 100% sensitivity. The power of skin cancer detection using electrical impedance is as good as, or better than, conventional visual screening made by general practitioners.

Non-invasive and microinvasive electrical impedance spectra of skin cancer - a comparison between two techniques

Background/purpose: Bio‐electrical impedance spectra of skin cancer and other lesions can be assessed using both regular non‐invasive probes and a novel type of microinvasive electrode system with a surface furnished with tiny spikes that penetrate stratum corneum. The aim of the study was to compare the accuracy of detection for various types of skin cancer using impedance spectra measured with these two different electrode systems in an objective way without optimising the power of discrimination.

Electrical impedance measurements at different skin sites related to seasonal variations.

Background/aims: In a previous study we mapped differences in electrical impedance between different anatomical locations related to age and sex. Now we employ the electrical impedance technique for studying the seasonal variations for the same skin sites.

Assessment of skin lesions and skin cancer using simple electrical impedance indices

Background/aims: Purpose of this investigation was to assess benign pigmented cellular nevus (BEN), basal cell carcinoma (BCC), dermatofibroma (DER), dysplastic nevus (DYS), and seborrheic keratoses (SEB) using in vivo non‐ invasive electrical impedance technique.

Clinically normal atopic skin vs. non-atopic skin as seen through electrical impedance

Background/aims: In an earlier study, we have shown that the electrical impedance (IMP) is dependent on the lipid content of the stratum corneum as studied by lipid extraction. Therefore, we now employ the IMP technique to compare the properties of clinically normal atopic skin with that of non‐atopic skin. We looked at the same time at concomitant alterations in transepidermal water loss (TEWL) and skin moisture results.

Electric Impedance Measurements at Six Different Anatomic Locations of Macroscopically Normal Human Oral Mucosa

We have used an electric impedance technique to explore the properties of the oral mucosa at various sites in the normal mouth. Investigations were performed on 26 healthy non-smoking subjects at 12 test areas, representing a range of mucosal types. Electric impedance spectra were measured in the frequency range 1 kHz to 1 MHz at five depth penetration settings of the instrument, and four indices were calculated for each depth. Statistically significant differences in the indices were found between most of these locations but not between contralateral sites at a similar position. The differences between some areas were considerably greater, and the differences between contralateral sites were smaller, than those encountered in the skin. Our results suggest that the choice of site for investigation of the oral cavity is more critical than with experimentation on the skin and that cognizance of this fact makes the oral cavity readily available for studies by the impedance method.

The use of different concentrations of betaine as a reducing irritation agent in soaps monitored visually and non-invasively

Background/aims: Products containing detergents can damage the skin and give rise to irritant contact dermatitis. Therefore, attempts have been made to find less irritating detergents as well as substances decreasing undesired side‐effects of detergents, and a novel approach is offered by betaine. The aim of the study has been to determine the irritating properties of some liquid soaps for personal hygiene and to map the effect of different concentrations of betaine using electrical impedance, trans‐epidermal water loss and visual inspection.

The ability of betaine to reduce the irritating effects of detergents assessed visually, histologically and by bioengineering methods

Background/aims: A novel approach for reducing the undesired irritating properties of detergents on skin might be offered by betaine, which is a natural product derived from the sugar beet. The aim of the study was to explore the ability of betaine to reduce the irritating effects of two surfactants, sodium lauryl sulphate (SLS) and cocoamidopropylbetaine (CAPB). For evaluation of changes in skin reactions visual scoring, electrical impedance, transepidermal water loss and histology were used.

Variation of skin properties within human forearms demonstrated by non-invasive detection and multi-way analysis

Background/aim: It is known that the properties of human skin vary locally. The purpose of this study was to investigate the properties of human volar forearms even further using advanced non‐invasive techniques and numerical methods.

Betaine reduces the irritating effect of sodium lauryl sulfate on human oral mucosa in vivo

Our aim was to evaluate whether betaine has a protective effect during exposure of the human oral mucosa in vivo to sodium lauryl sulfate (SLS) or cocoamidopropylbetaine (CAPB) as measured with a multifrequency electrical impedance spectrometer (EI). Both detergents were used at the concentration of 2.0% w/v with and without 4.0% w/v betaine in distilled water in 20 volunteers, and 0.5% and 1.0% w/v SLS combined with 4.0% w/v betaine in 5 volunteers. EI measurements were taken before application of the test solutions, after their removal, and every 15 min up to 45 min. Both 0.5% and 1% SLS solutions showed a significant reduction in 3 of the 4 indices, indicating mucosal irritation after the 15-min exposure (P < 0.05), whereas 2% SLS did so in all 4 indices (P < 0.001). Betaine had no effect on the detergent-induced decline with either the 2% or the 0.5% SLS solutions. However, when combined with the 1% SLS solution, betaine significantly (P < 0.05) reduced mucosal irritation by abolishing decreases in indices MIX (magnitude index) and IMIX (imaginary part index) and lowering it for PIX (phase index). The 2% CAPB solution showed a significant (P < 0.05) reduction in all 4 indices after the 15-min exposure, but the effect was significantly weaker than that of 2% SLS (P < 0.05). Betaine did not reduce the irritating effect of 2% CAPB. These findings can be used in the development of less irritating products for oral health care.