Optical Non-Invasive Approaches to Diagnosis of Skin Diseases

A number of noninvasive approaches have been developed over the years to provide objective evaluation of the skin both in health and in disease. The advent of computers, as well as of lasers and photonics, has made it possible to develop additional techniques that were impossible a few years ago. These approaches provide the dermatologist with sensitive tools to measure the skin's condition in terms of physiologic parameters (e.g., color, erythema and pigmentation, induration, sebaceous and stratum corneum lipids, barrier function, etc.). Yet, a typical dermatologic diagnosis relies primarily on the trained eyes of the physician and to a lesser extent on information from other senses, such as touch and smell. The trained senses of the dermatologist backed by his/her brain form a powerful set of tools for evaluating the skin. The golden rule in diagnosis remains the histologic examination of a skin biopsy, a rather invasive method. These tools have served the profession well. The advent of ever faster and cheaper computers and of sensitive, inexpensive optical instrumentation of minimal dimensions provides the professional with the possibility of making objective measures of a number of skin parameters

Objective Assessment of Area and Erythema of Psoriasis Lesion Using Digital Imaging and Colourimetry

Psoriasis is a non-contagious skin disease which typically consists of red plaques covered by silvery-white scales. It affects about 3% of world population. During treatment, dermatologists monitor the extent of psoriasis continuously to ascertain treatment efficacy. Psoriasis Area and Severity Index (PAS!) is the current gold standard method used to assess the extent of psoriasis. In PAS!, there are four parameters to be scored i.e., the surface area affected, erythema (redness), thickness and scaliness of the plaques. Determining PAS! score is a tedious task and thus it is not used in daily clinical practice. In addition, the PAS! parameters are visually determined and may result in intra-observer and inter-observer variations, even by experienced dermatologists. Objective methods in assessing area and erythema of psoriasis lesion have been developed in this thesis. Psoriasis lesion can be recognized by its colour dissimilarity with normal skin. Colour dissimilarity is represented by colour difference in CIELAB colour space, a widely used colour space to measure colour dissimilarity. Each pixel in CIELAB colour space can be represented by its lightness (L'), hue (hob), and chroma (Cab). Colour difference between psoriasis lesion and normal skin is analyzed in hue-chroma plane of CIELAB colour space. Centroids of normal skin and lesion in hue-chroma space are obtained from selected samples. Euclidean distances between all pixels with these two centroids are then calculated. Each pixel is assigned to the class of the nearest centroid. The erythema of psoriasis lesion is affected by degree of severity and skin pigmentation. In order to assess the erythema objectively, patients are grouped according to their skin pigmentation level. The L* value of normal skin which represents skin pigmentation level is utilized to group the patient into the three skin types namely fair, brown and dark skin types. Light difference (t.L*), hue difference (t.hab), and chroma difference (t.C'ab) of CIELAB colour space between reference lesions and the surrounding normal skin are analyzed. It is found that the erythema score of a lesion can be determined by their hue difference (t.hab) value within a particular skin type group. Out of 30 body regions, the proposed method is able to give the same PAS! area score as reference for 28 body regions. The proposed method is able to determine PAS! erythema score of 82 lesions obtained from 22 patients objectively without being influenced by other characteristic of the lesion such as area, pattern, and boundary

Digital dermoscopy to determine skin melanin index as an objective indicator of skin pigmentation

Clinical assessment of skin photosensitivity is subjectively determined by erythema and tanning responses to sunlight recalled by the subject, alternatively known as Fitzpatrick Skin Phototype (SPT). Responses may be unreliable due to recall bias, subjective bias by clinicians and subjects, and lack of cultural sensitivity of the questions. Analysis of red-green-blue (RGB) color spacing of digital images may provide an objective determination of SPT. This paper presents the studies to assess the melanin index (MI), as determined by RGB images obtained by both standard digital camera as well as by videodermoscope, and to correlate the MI with SPT based upon subjects' verbal responses to standardized questions administered by a dermatologist. A sample of subjects representing all SPTs I–VI was selected. Both the digital camera and videodermoscope were calibrated at standard illumination, light source and white balance. Images of constitutive skin of the upper ventral arm were taken of each subject using both instruments. The studies showed that 58 subjects (20 M, 38 F) were enrolled in the study (mean age: 47 years; range: 20–89), stratified to skin phototype I–VI. MI obtained by using both digital camera and videodermoscope increased significantly as the SPT increased (p = 0.004 and p &lt; 0.0001, respectively) and positively correlated with dermatologist-assessed SPT (Spearman correlation, r = 0.48 and r = 0.84, respectively). Digital imaging can quantify melanin content in order to quantitatively approximate skin pigmentation in all skin phototypes including Type VI skin. This methodology holds promise as a simple, non-invasive, rapid and objective approach to reliably determine skin phototype and, with further investigation, may prove to be both practical and useful in the prediction of skin cancer risk.</p

Hyperspectral Imaging and Classification for Grading Skin Erythema

International audienceErythema is an inflammatory condition of the skin that is commonly used as a feature to monitor the progression of cutaneous diseases or treatment induced side effects. In radiation therapy, skin erythema is routinely assessed visually by an expert using standardized grading criteria. However, visual assessment (VA) is subjective and commonly used grading tools are too coarse to score the onset of erythema. Therefore, an objective method capable of quantitatively grading early erythema changes may help identify patients at higher risk for developing severe radiation induced skin toxicities. The purpose of this study is to investigate the feasibility of using hyperspectral imaging (HSI) for quantitative assessment of early erythema and to characterize its performance against VA documented on conventional digital photographic red-green-blue (RGB) images. Erythema was induced artificially on 3 volunteers in a controlled pilot study; and was subsequently measured using HSI and color imaging. HSI and color imaging data was analyzed using linear discriminant analysis (LDA) to perform classification. The classification results, including accuracy, and precision, demonstrated that HSI is superior to color imaging in skin erythema assessment

Non-invasive clinical and microscopic evaluation of the response to treatment with clobetasol cream vs. calcipotriol/betamethasone dipropionate foam in mild to moderate plaque psoriasis : an investigator-initiated, phase IV, unicentric, open, randomized clinical trial

Treatment response for psoriasis is typically evaluated using clinical scores. However, patients can relapse after clinical clearance, suggesting persistent inflammation. Dermoscopy, reflectance confocal microscopy (RCM) and optical coherence tomography (OCT) can non-invasively improve treatment response assessment. To compare the clinical and non-invasive microscopic features in a psoriatic target lesion treated with clobetasol cream or calcipotriol/betamethasone dipropionate foam (Cal/BD foam). Prospective, unicentric, open, randomized clinical trial comparing clinical data [total clinical score (TCS)] and microscopic data (dermoscopy, RCM and OCT) in psoriasis patients treated with clobetasol or Cal/BD foam. We included 36 adult patients (22 men). At week 4, more patients treated with Cal/BD foam achieved TCS ≤1 than with clobetasol (63.2% vs. 18.8%, P = 0.016). Treatment satisfaction was higher with Cal/BD foam (P < 0.03). Microscopically, Cal/BD foam induced more reduction in epidermal thickness at week 4 (P < 0.049). Dilated horizontal blood vessels were more common with clobetasol than with Cal/BD foam at week 8 (69.2% vs. 31.2%, P = 0.159). If epidermal hyperplasia was noted at baseline, the response was poorer with clobetasol (P = 0.029). Small sample size, open study, imaging sampling bias. Cal/BD foam is more effective than clobetasol, has better patient satisfaction and induces greater reduction in the hyperkeratosis/acanthosis, regardless of baseline epidermal hyperplasia

Formulation And Evaluation of Herbal Ointment on Different Extract of Whole Plant of Indigofera Aspalathoides. Vahl.ex.Dc., to Treat Psoriasis

INTRODUCTION: Herbalism: Herbalism is the study of botany and use of plants intended for medicinal purposes or for supplementing a diet. Herbalism is also known as botanical medicine, medicinal herbalism, herbal medicine, herbology, herblore, and phytotherapy Herbal Medicine: Herbal medicines are being used by about 80% of the world population primarily in the developing countries for primary health care. They have stood the test of time for their safety, efficacy, cultural acceptability and lesser side effects. Ancient literature also mentions herbal medicines for age-related diseases namely memory loss, osteoporosis, osteoarthritis, diabetes, immune and liver disorders, etc. for which no modern medicine or only palliative therapy is available4. The chemical constituents present in them are a part of the physiological functions of living flora and hence they are believed to have better compatibility with the human body5. There are over 1.5 million practitioners of traditional medicinal system using medicinal plants in preventive, promotional and curative applications. Medicinal plants have attracted the attention of not only professionals from various systems of medicine, but also the scientific communities belonging to different disciplines, plants are promising source of herbal formulation6. The use of herbal drugs due to toxicity and side effects of allopathic medicines, has led to rapid increase in the number of herbal drug manufacturers. For the past few decades, herbal drugs have been more and more consumed by the people with no prescription. These drugs have survived real world testing and thousands of years of human testing. Some drugs have been discontinued due to their toxicity, while others have been modified or combined with additional herbs to counterbalance side effects. AIM AND OBJECTIVES: Indigofera aspalathoides plant are used in the treatment of skin disease in ethanomedicine. The literature survey indicates that no scientific data on the anti psoriatic activity of this plant. Various parts of these plants have been claimed to be effective in a wide range of disease .The scientifically state therapeutic properties for Indigofera aspalathoides have reported antimicrobial, anti-inflammatory, anticancerous, anti-oxidant, hypoglycemic, hepatoprotective, antiviral, Antitumor activity Antidiabetic ,Wound Healing64-71 . Rationale of the study The allopathic drugs like methotrexate, corticosteroids and immuno suppressant shows effective response in psoriasis by reducing the scale ,plaque ,cell proliferation and inflammation but the adverse reaction is severe than the efficacy of the drug .the long term usage of drug causes serious adverse reaction like hepatotoxicity, renal failure sometimes leads to fatality.So the herbal drugs are safe in psoriasis treatment since the adverse effect is mild or nil and lower the cost of therapy as comparable to the allopathic medicine. The present investigation was therefore proposed to: 1. To evaluate the anti-microbial activity related to psoriasis from the different extract of whole plant of Indigofera aspalathoides. 2. To formulate herbal ointment with different extract of whole plant of indigofera aspalathoides. 3. To evaluate the formulated herbal ointment 4. To evaluate the anti-psoriatic activity of ointment by mice skin test. SUMMARY AND CONCLUSION: Indigofera aspalathoides plant is used in traditionally in the treatment of skin disease. The literature survey indicates that no scientific data on the anti-psoriatic activity of this plant. Various parts of this plant have been claimed to be effective in a wide range of disease. The allopathic drugs like methotrexate, corticosteroids and immune suppressants shows effective response in psoriasis by reducing the scales, plaque, cell proliferation and inflammation but the adverse reaction is severe than the efficacy of the drug. The long term usage of drug causes serious adverse reaction like hepatotoxicity, renal failure sometimes lead to fatality. So herbal drugs are safe in psoriasis treatment since the adverse effect is mild or nil and lower the cost of therapy as comparable to the allopathic medicine. The morphological and physiochemical properties of the whole plant were evaluated. Different extract of whole plant powder were prepared and these extracts were subjected to phytochemical evaluation. The ethanolic extract showed the presence of various phyto constituents such as ,Steroids, flavonoids, alkaloids and carbohydrates. All the extract was tested for anti-microbial activity. Ethyl acetate and ethanol extract showed good activity even at low concentration and also shows maximum zone of inhibition. The ethanolic extract were formulated as an ointment in a concentration of 2%w/w and 4%w/w evaluated for anti-psoriatic activity. The ointment were then pharmacologically evaluated for their anti psoriatic activity using mice skin model test. The ointment prepared with ethanolic extract showed antipsoriatic activity which was comparable to the standard clobetasol cream. The activity of ethanol extract cream was seen to be superior to standard ointment. The ethanolic extract was subjected to HPTLC finger printing to establish an identity for future comparison. An attempt was also made to isolate the active constituents from the ethanol extract. The present study confirms the anti-psoriatic activity of ethanol extract of Indigofera aspalathoides., whole plant by various studies including in vitro and in vivo as mentioned in the study .The efficacy of the ointment could also be evaluated for clinical settings

Incorporating Colour Information for Computer-Aided Diagnosis of Melanoma from Dermoscopy Images: A Retrospective Survey and Critical Analysis

Cutaneous melanoma is the most life-threatening form of skin cancer. Although advanced melanoma is often considered as incurable, if detected and excised early, the prognosis is promising. Today, clinicians use computer vision in an increasing number of applications to aid early detection of melanoma through dermatological image analysis (dermoscopy images, in particular). Colour assessment is essential for the clinical diagnosis of skin cancers. Due to this diagnostic importance, many studies have either focused on or employed colour features as a constituent part of their skin lesion analysis systems. These studies range from using low-level colour features, such as simple statistical measures of colours occurring in the lesion, to availing themselves of high-level semantic features such as the presence of blue-white veil, globules, or colour variegation in the lesion. This paper provides a retrospective survey and critical analysis of contributions in this research direction