Computer-aided measurement of psoriatic lesion area in a multicenter clinical trial—Comparison to physician's estimations

Current and Emerging Imaging Techniques for Neurofibromatosis Type 1-Associated Cutaneous Neurofibromas

A consistent set of measurement techniques must be applied to reliably and reproducibly evaluate the efficacy of treatments for cutaneous neurofibromas (cNFs) in people with neurofibromatosis type 1 (NF1). cNFs are neurocutaneous tumors that are the most common tumor in people with NF1 and represent an area of unmet clinical need. This review presents the available data regarding approaches in use or development to identify, measure, and track cNFs, including calipers, digital imaging, and high-frequency ultrasound sonography. We also describe emerging technologies such as spatial frequency domain imaging and the application of imaging modalities such as optical coherence tomography that may enable the detection of early cNFs and prevention of tumor-associated morbidity.

Automated psoriasis lesion segmentation from unconstrained environment using residual U-Net with transfer learning

BACKGROUND AND OBJECTIVE

The automatic segmentation of psoriasis lesions from digital images is a challenging task due to the unconstrained imaging environment and non-uniform background. Existing conventional or machine learning-based image processing methods for automatic psoriasis lesion segmentation have several limitations, such as dependency on manual features, human intervention, less and unreliable performance with an increase in data, manual pre-processing steps for removal of background or other artifacts, etc. METHODS: In this paper, we propose a fully automatic approach based on a deep learning model using the transfer learning paradigm for the segmentation of psoriasis lesions from the digital images of different body regions of the psoriasis patients. The proposed model is based on U-Net architecture whose encoder path utilizes a pre-trained residual network model as a backbone. The proposed model is retrained with a self-prepared psoriasis dataset and corresponding segmentation annotation of the lesion.

RESULTS

The performance of the proposed method is evaluated using a five-fold cross-validation technique. The proposed method achieves an average Dice Similarity Index of 0.948 and Jaccard Index of 0.901 for the intended task. The transfer learning provides an improvement in the segmentation performance of about 4.4% and 7.6% in Dice Similarity Index and Jaccard Index metric respectively, as compared to the training of the proposed model from scratch.

CONCLUSIONS

An extensive comparative analysis with the state-of-the-art segmentation models and existing literature validates the promising performance of the proposed framework. Hence, our proposed method will provide a basis for an objective area assessment of psoriasis lesions.

The indirect effect of a focus group for psoriatic patients on their caregivers

Psoriasis is a chronic skin disease involving not only epidermic damages but also psychological distress for patients and their family caregivers. Little is known about the effects of a psychological support for psoriatic patients on their caregivers’ well-being. The goal of the present study was to investigate the indirect effects of the participation in a dynamic focus group reserved for psoriatic patients on their caregivers in terms of quality of life. The study involved 52 psoriatic patients and 41 family caregivers. Patients’ wellbeing was assessed using the dermatology quality of life index, hospital anxiety and depression scale. The impact of the disease on caregivers was assessed using the family dermatology life quality index (FDLQI). Data were analyzed with linear mixed models. The caregivers of psoriatic patients involved in the psychodynamic focus group reported levels of FDLQI that decreased over time, therefore showing an improvement in their quality of life in relation to the pathology of their relatives; the caregivers of patients who did not participate in the psychodynamic focus group, instead, had levels of FDLQI that were stable over time. The results provide preliminary evidence that the group setting of the Psychodynamic Focus Group may alleviate the negative impact of psychosomatic disease on the caregivers.

Joint AAD-NPF Guidelines of care for the management and treatment of psoriasis with topical therapy and alternative medicine modalities for psoriasis severity measures

Psoriasis is a chronic, inflammatory, multisystem disease that affects up to 3.2% of the United States population. This guideline addresses important clinical questions that arise in psoriasis management and care and provides recommendations based on the available evidence. The treatment of psoriasis with topical agents and with alternative medicine will be reviewed, emphasizing treatment recommendations and the role of dermatologists in monitoring and educating patients regarding benefits as well as risks that may be associated. This guideline will also address the severity assessment methods of psoriasis in adults.

Psoriasis and IgE-mediated allergy: correlation or mutual inhibition? : A prospective cohort study in patients with mild or moderate to severe psoriasis

BACKGROUND

Psoriasis is an autoimmune disease caused by overactivation of T_H1 (Type 1 helper cells) and T_H17 (T helper 17) cells. Overactivation of T_H1 cells inhibits the activity of T_H2 cells involved in type 1 allergies, therefore, psoriasis patients might be less affected by type 1 allergies. This study tested if allergies were less frequent in patients with moderate to severe than with mild psoriasis.

METHODS

Psoriasis patients at the study site reported possible allergy symptoms and were tested for common allergens by skin prick test and IgE levels. Psoriasis was classified by PASI scores (Psoriasis Area and Severity Index) as mild (PASI <10) or moderate/severe (PASI ≥10). Patients without systemic therapy were assessed separately. Fisher's exact test was used to test for differences.

RESULTS

A total of 97 patients were included, 21 with mild and 76 with moderate to severe psoriasis. Allergies were found in 27.8%, most commonly against dust mites (23.4%) and grasses (18.1%). Allergies were found in 23.8% of the patients with mild vs. 29.0% allergic patients with moderate to severe psoriasis (P = 0.786). In patients without systemic medication, allergies were found in 21.1% vs. 35.3% (P = 0.463).

CONCLUSION

Allergy prevalence was not reduced in patients with moderate/severe psoriasis, and generally close to the prevalence in the general Austrian population (24%). The inhibiting effect of psoriasis on type 1 allergies was not confirmed.

Validation of an Optical Pencil Method to Estimate the Affected Body Surface Area in Psoriasis

INTRODUCTION

Body surface area (BSA) affected by psoriasis is one of the most often used measures for assessing severity, but this method has shortcomings.

OBJECTIVE

To validate a new way to estimate BSA.

MATERIAL AND METHOD

Prospective, multicenter study in 56 patients with psoriasis. Each patient was evaluated by 2 dermatologists in 2 visits to the same hospital. Each dermatologist used 2 methods for estimating BSA: the traditional visual estimation in which the area of the palm equals 1% of the total body surface and an optical pencil (OP) method in which the affected area is drawn on a touch screen. Software in the application then calculates the BSA.

RESULTS

Overall concordance between the 2 methods was acceptable according to an intraclass correlation coefficient (ICC) of 0.87. However, the limits of agreement were unacceptably large and there was systematic bias: traditional estimates were consistently greater than OP calculations. Concordance between the methods was better (ICC>0.8) on the trunk and lower extremities. Intraobserver reliability was excellent with both methods (ICCs, 0.97 and 0.98 for the traditional and OP estimates, respectively). Interobserver reliability was also high (ICCs, 0.91 and 0.94 for the traditional and OP methods), although the mean BSA differed significantly between observers. The ICCs were much lower for BSA estimates on the head.

CONCLUSIONS

This study to validate the OP method for estimating the affected BSA in patients with psoriasis shows good agreement between the OP and traditional approaches. The OP calculations also showed less variance and better interobserver reliability.

Emerging imaging technologies in dermatology: Part II: Applications and limitations

Clinical examination is critical for the diagnosis and identification of response to treatment. It is fortunate that technologies are continuing to evolve, enabling augmentation of classical clinical examination with noninvasive imaging modalities. This article discusses emerging technologies with a focus on digital photographic imaging, confocal microscopy, optical coherence tomography, and high-frequency ultrasound, as well as several additional developing modalities. The most readily adopted technologies to date include total-body digital photography and dermoscopy, with some practitioners beginning to use confocal microscopy. In this article, applications and limitations are addressed. For a detailed discussion of the principles involved in these technologies, please refer to the first part of this review article.

Serum Squamous Cell Carcinoma Antigen in Psoriasis: A Potential Quantitative Biomarker for Disease Severity

BACKGROUND

An objective and quantitative method to evaluate psoriasis severity is important for practice and research in the precision care of psoriasis.

OBJECTIVES

We aimed to explore serum biomarkers quantitatively in association with disease severity and treatment response in psoriasis patients, with serum squamous cell carcinoma antigen (SCCA) evaluated in this pilot study.

METHODS

15 psoriasis patients were treated with adalimumab. At different visits before and after treatment, quantitative body surface area (qBSA) was obtained from standardized digital body images of the patients, and the psoriasis area severity index (PASI) was also monitored. SCCA were detected by using microparticle enzyme immunoassay. The serum biomarkers were also tested in healthy volunteers as normal controls. Receiver-operating characteristic (ROC) curve analysis was used to explore the optimal cutoff point of SCCA to differentiate mild and moderate-to-severe psoriasis.

RESULTS

The serum SCCA level in the psoriasis group was significantly higher (p < 0.05) than in the normal control group. After treatment, the serum SCCA levels were significantly decreased (p < 0.05). The SCCA level was well correlated with PASI and qBSA. In ROC analysis, when taking PASI = 10 or qBSA = 10% as the threshold, an optimal cutoff point of SCCA was found at 2.0 ng/mL with the highest Youden index.

CONCLUSION

Serum SCCA might be a useful quantitative biomarker for psoriasis disease severity.

A novel and robust Bayesian approach for segmentation of psoriasis lesions and its risk stratification

BACKGROUND AND OBJECTIVE

The need for characterization of psoriasis lesion severity is clinically valuable and vital for dermatologists since it provides a reliable and precise decision on risk assessment. The automated delineation of lesion is a prerequisite prior to characterization, which is challenging itself. Thus, this paper has two major objectives: (a) design of a segmentation system which can model by learning the lesion characteristics and this is posed as a Bayesian model; (b) develop a psoriasis risk assessment system (pRAS) by crisscrossing the blocks which drives the fundamental machine learning paradigm.

METHODS

The segmentation system uses the knowledge derived by the experts along with the features reflected by the lesions to build a Bayesian framework that helps to classify each pixel of the image into lesion vs.

BACKGROUND

Since this lesion has several stages and grades, hence the system undergoes the risk assessment to classify into five levels of severity: healthy, mild, moderate, severe and very severe. We build nine kinds of pRAS utilizing different combinations of the key blocks. These nine pRAS systems use three classifiers (Support Vector Machine (SVM), Decision Tree (DT) and Neural Network (NN)) and three feature selection techniques (Principal Component Analysis (PCA), Fisher Discriminant Ratio (FDR) and Mutual Information (MI)). The two major experiments conducted using these nine systems were: (i) selection of best system combination based on classification accuracy and (ii) understanding the reliability of the system. This leads us to computation of key system performance parameters such as: feature retaining power, aggregated feature effect and reliability index besides conventional attributes like accuracy, sensitivity, specificity.

RESULTS

Using the database used in this study consisted of 670 psoriasis images, the combination of SVM and FDR was revealed as the optimal pRAS system and yielded a classification accuracy of 99.84% using cross-validation protocol. Further, SVM-FDR system provides the reliability of 99.99% using cross-validation protocol.

CONCLUSIONS

The study demonstrates a fully novel model of segmentation embedded with risk assessment. Among all nine systems, SVM-FDR produced best results. Further, we validated our pRAS system with automatic segmented lesions against manually segmented lesions showing comparable performance.

Computer-aided analysis with Image J for quantitatively assessing psoriatic lesion area

BACKGROUND/AIMS

Body surface area is important in determining the severity of psoriasis. However, objective, reliable, and practical method is still in need for this purpose. We performed a computer image analysis (CIA) of psoriatic area using the image J freeware to determine whether this method could be used for objective evaluation of psoriatic area.

METHODS

Fifteen psoriasis patients were randomized to be treated with adalimumab or placebo in a clinical trial. At each visit, the psoriasis area of each body site was estimated by two physicians (E-method), and standard photographs were taken. The psoriasis area in the pictures was assessed with CIA using semi-automatic threshold selection (T-method), or manual selection (M-method, gold standard). The results assessed by the three methods were analyzed with reliability and affecting factors evaluated.

RESULTS

Both T- and E-method correlated strongly with M-method, and T-method had a slightly stronger correlation with M-method. Both T- and E-methods had a good consistency between the evaluators. All the three methods were able to detect the change in the psoriatic area after treatment, while the E-method tends to overestimate.

CONCLUSION

The CIA with image J freeware is reliable and practicable in quantitatively assessing the lesional of psoriasis area.

Paraoxonase 1 (PON1) 55 polymorphism, lipid profiles and psoriasis

BACKGROUND

Paraoxonase 1 (PON1) is a serum high-density lipoprotein-bound enzyme with antioxidant function. It hydrolyses lipid peroxides, protecting low-density lipoproteins from oxidative modifications. Patients with psoriasis are at greater risk of oxidative stress, which is associated with abnormal plasma lipid metabolism.

OBJECTIVES

In this study, association of the PON1 55 M allele with serum arylesterase (ARE) activity, malondialdehyde (MDA), lipid profiles and psoriasis was investigated.

METHODS

The present case-control study consisted of 100 patients with psoriasis with and without cardiovascular diseases (mean age 35·3 years) and 100 sex- and age-matched unrelated healthy controls (mean age 35·7 years) from the population of western Iran. The PON1 55 Met>Leu polymorphism was detected by polymerase chain reaction-restriction fragment length polymorphism. Serum ARE activity, MDA, and lipid and apolipoprotein levels were determined spectrophotometrically, by high-performance liquid chromatography and by enzyme assay, respectively.

RESULTS

The presence of the PON1 55 M allele was found to be associated with psoriasis (odds ratio = 1·96, P = 0·017). The patients with psoriasis with the PON1 M (M/L + M/M) allele had higher MDA levels (4·12 ± 0·88 vs. 2·24 ± 0·55 μmol L(-1) , P < 0·001), apolipoprotein B (APOB)/APOA1 ratio (0·91 ± 0·66 vs. 0·66 ± 0·35, P = 0·004), APOB (111 ± 38·7 vs. 88·3 ± 22·5 mg mL(-1) , P = 0·001) and lipoprotein(a) [LP(a)] (21·9 ± 18·4 vs. 15·8 ± 16·6 mg mL(-1) , P = 0·034), but lower ARE activity (39·6 ± 11 vs. 45·9 ± 11·8 U mL(-1) , P = 0·031) than the control subjects. ARE activity showed a significant positive correlation with APOA1 and a negative correlation with MDA concentration in patients with psoriasis.

CONCLUSIONS

The PON1 55 M allele is a risk factor for psoriasis. Carriers of this allele have high levels of MDA, APOB and LP(a), a high APOB/APOA1 ratio and low ARE activity. These results indicate that oxidative stress, impairment of the antioxidant system and abnormal lipid metabolism may play a role in the pathogenesis and progression of psoriasis and its related complications. These data suggest that patients with psoriasis are more susceptible to vascular diseases.

Psoriasis segmentation through chromatic regions and Geometric Active Contours

We present a novel approach to the segmentation of psoriasis lesions in "full body" digital photographs potentially involving dozens or even hundreds of separate lesions. Our algorithm first isolates a set of zones that certainly correspond to lesional plaques based on chromatic information, and then expands these zones to achieve an accurate segmentation of plaques through a Geometric Active Contours method. The variability in segmentation between our algorithm and different human operators appears comparable to the variability between human operators.

Semi-quantitative assessment of the distribution of skin lesions in patients with psoriasis and psoriasis arthritis

BACKGROUND

We propose that the distribution of skin lesions in psoriasis may be assessed using parametric maps on a pixel-by-pixel basis.

MATERIAL AND METHODS

We processed 428 patient-drawn self-descriptions of the psoriasis lesions on a supplied body template. We compared 195 patients with a confirmed diagnosis of psoriatic arthritis (PsA) with 89 who had this diagnosis rejected (Psor). Additionally, 28 Psor cases supplied drawings performed after 3 weeks of climate therapy (PsorCT) to test the treatment efficacy. The drawings were scanned, lesion areas were segmented, followed by construction of parametric maps of lesion distributions and calculation of statistical differences between groups.

RESULTS AND DISCUSSION

In PsorCT, the lesions occupied 11.2% (0-42%) [median (min.-max.)] of the body area. The area decreased to 2.4% (6-11%) after heliotherapy. The differences were statistically significant for all the areas studied and spread evenly over the body surface. PsA had a relatively low psoriasis lesion occupancy of 2.5% (0-42%) compared with Psor 9.8% (0-34%), which is attributed to the difference in recruitment. Correcting for this, we demonstrate a clear tendency for the head, palms, feet, groin and nails to be preferred lesion sites in PsA in contrast to psoriasis.

CONCLUSION

Pixel-based analysis of self-reported skin lesion distributions is a powerful tool to assess systematic differences due to treatment or disease variants.