Classification Framework for Healthy Hairs and Alopecia Areata: A Machine Learning (ML) Approach.

Alopecia areata is defined as an autoimmune disorder that results in hair loss. The latest worldwide statistics have exhibited that alopecia areata has a prevalence of 1 in 1000 and has an incidence of 2%. Machine learning techniques have demonstrated potential in different areas of dermatology and may play a significant role in classifying alopecia areata for better prediction and diagnosis. We propose a framework pertaining to the classification of healthy hairs and alopecia areata. We used 200 images of healthy hairs from the Figaro1k dataset and 68 hair images of alopecia areata from the Dermnet dataset to undergo image preprocessing including enhancement and segmentation. This was followed by feature extraction including texture, shape, and color. Two classification techniques, i.e., support vector machine (SVM) and k-nearest neighbor (KNN), are then applied to train a machine learning model with 70% of the images. The remaining image set was used for the testing phase. With a 10-fold cross-validation, the reported accuracies of SVM and KNN are 91.4% and 88.9%, respectively. Paired sample T-test showed significant differences between the two accuracies with a p < 0.001. SVM generated higher accuracy (91.4%) as compared to KNN (88.9%). The findings of our study demonstrate potential for better prediction in the field of dermatology.

Elevated serum tumour necrosis factor-like weak inducer of apoptosis in alopecia areata: a possible marker of disease severity.

BACKGROUND: Alopecia areata (AA) is, an organ-specific autoimmune disease, characterized by an aberrant expression of cytokines of the T helper 1 type. Tumour necrosis factor-like weak inducer of apoptosis (TWEAK) is a multifactorial cytokine that exerts a role in the pathogenesis of inflammatory and autoimmune diseases, especially in cutaneous diseases. AIM: To estimate the serum level of TWEAK in AA and to correlate it with different parameters. METHODS: This case-control study enrolled 40 patients with AA and 50 clinically healthy volunteers matched for age and sex. A blood sample (5 mL) was extracted from each participant for analysis of serum TWEAK levels by ELISA. RESULTS: Levels of TWEAK were significantly higher in patients with AA (mean ± SD 213.7 ± 59.2 pg/mL, range 109.1-341.6 pg/mL) than in controls (95.97 ± 13.28 pg/mL, range 80.1-152.3 pg/mL) (P < 0.001). A significant positive correlation was found between serum TWEAK level and the Severity of Alopecia Tool (SALT) score (r = 0.56, P < 0.001). CONCLUSION: To our knowledge, this study highlights for the first time a possible link between higher serum TWEAK level and AA. Serum TWEAK level appears to reflect AA disease severity.

Topographic Phenotypes of Alopecia Areata and Development of a Prognostic Prediction Model and Grading System: A Cluster Analysis.

Importance: Diverse assessment tools and classification have been used for alopecia areata; however, their prognostic values are limited. Objective: To identify the topographic phenotypes of alopecia areata using cluster analysis and to establish a prediction model and grading system for stratifying prognoses. Design, Setting, and Participants: A retrospective cohort study of 321 patients with alopecia areata who visited a single tertiary referral center between October 2012 and February 2017 and underwent 4-view photographic assessment. Exposures: Clinical photographs were reviewed to evaluate hair loss using the Severity of Alopecia Tool 2. Topographic phenotypes of alopecia areata were identified using hierarchical clustering with Ward's method. Differences in clinical characteristics and prognosis were compared across the clusters. The model was evaluated for its performance, accuracy, and interobserver reliability by comparison to conventional methods. Main Outcomes and Measures: Topographic phenotypes of alopecia areata and their major (60%-89%) and complete regrowth probabilities (90%-100%) within 12 months. Results: A total of 321 patients were clustered into 5 subgroups. Grade 1 (n = 200; major regrowth, 93.4%; complete regrowth, 65.2%) indicated limited hair loss, whereas grades 2A (n = 66; major regrowth, 87.8%; complete regrowth, 64.2%) and 2B (n = 20; major regrowth, 73.3%; complete regrowth, 45.5%) exhibited greater hair loss than grade 1. The temporal area was predominantly involved in grade 2B, but not in grade 2A, despite being comparable in total extent of hair loss. Grade 3 (n = 20; major regrowth, 45.5%; complete regrowth, 25.5%) included diffuse or extensive alopecia areata, and grade 4 (n = 15; major regrowth, 28.2%; complete regrowth, 16.7%) corresponded to alopecia (sub)totalis. No significant differences in prognosis (hazard ratio [HR] for major regrowth, 0.79; 95% CI, 0.56-1.12) were found between grades 2A and 1, whereas grades 2B (HR, 0.41; 95% CI, 0.21-0.81), 3 (HR, 0.24; 95% CI, 0.12-0.50), and 4 (HR, 0.16; 95% CI, 0.06-0.39) had significantly poorer response. Among multiple models, the cluster solution had the greatest prognostic performance and accuracy. The tree model of the cluster solution was converted into the Topography-based Alopecia Areata Severity Tool (TOAST), which revealed an excellent interobserver reliability among 4 dermatologists (median quadratic-weighted κ, 0.89). Conclusions and Relevance: Temporal area involvement should be independently measured for better prognostic stratification. The TOAST is an effective tool for describing the topographical characteristics and prognosis of hair loss and may enable clinicians to establish better treatment plans.

A prospective study of tinea capitis in children: making the diagnosis easier with a dermoscope.

INTRODUCTION: Tinea capitis is a scalp infection caused by different fungi. Etiological diagnosis is based on suggestive clinical findings and confirmation depends on the fungus growth in culture. However, it is not always possible to perform this test due to lack of availability. The association of clinical and dermatoscopic findings in suspected cases of tinea capitis may help the identification of the etiological agent, facilitating precocious, specific treatment. MATERIALS AND METHOD: We report a prospective descriptive analytical study of 34 children with tinea capitis. We performed a trichoscopic examination of all patients; only six children were able to have the mycological culture. RESULTS: Trichoscopy was abnormal in all 34 patients; it showed hair shaft abnormalities and, in some cases, scalp disorders too. We found that the comma and corkscrew appearance was found in microsporic tinea capitis, V-shaped hair was mainly seen in inflammatory tinea capitis, scales and follicular keratosis in non-inflammatory tinea capitis, and crusts and follicular pustules in inflammatory tinea capitis. Finally, erythema was seen in trichophytic and inflammatory tinea capitis. CONCLUSION: We propose a classification of trichoscopic signs of tinea capitis. This classification will enable rapid diagnosis and prediction of the type of fungus before mycological culture, thus a faster and more adapted management. Our study shows the importance of trichoscopy in the diagnosis and monitoring of tinea capitis. We suggest further prospective studies with a larger number of patients with tinea capitis, having performed mycological culture, to confirm this classification.

Alopecia areata y pustulosis palmoplantar: informe de 4 casos / Alopecia Areata and Palmoplantar Pustulosis: Report of 4 Cases

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Role of T helper 17 cells and T regulatory cells in alopecia areata: comparison of lesion and serum cytokine between controls and patients.

BACKGROUND: Alopecia areata (AA) is an organ-specific autoimmune disease with T-cell-mediated attack of hair follicle autoantigens. As T helper 17 (Th17) cells and T regulatory (Treg) cells are crucially involved in the pathogenesis, the role of Th17 and Treg cytokines has not been studied yet. OBJECTIVE: To determine whether AA is associated with alterations in lesional and serum Th17 and Treg cytokines and studied whether they were associated with clinical type. METHODS: Scalp skin samples from 45 patients and eight normal controls were obtained for PCR specific for IFN-γ, TNF-α, TGF-ß, IL-1, IL-2, IL-4, IL-10, IL-12A, IL-13, IL-17, IL-22 and IL-23. Serum cytokines were measured from 55 patients and 15 normal controls using ELISA. RESULTS: Lesional IL-17 and IL-22 were significantly increased in patient group. Moreover, positive correlations were shown between lesional IL-17, IL-22 and disease severity. Serum IL-1, IL-17, TNF-α and TGF-ß were significantly increased, and positive correlation was shown between serum IL-17 and disease severity. CONCLUSION: These results showed significantly high Th17 cytokines in both lesion and serum in AA patients, which may highlight a functional role of these cytokines in the pathogenesis of AA.

Gender differences in alopecia areata.

Alopecia areata (AA) is a common, non-scarring, autoimmune hair-loss disorder with a complex genetic and environmental etiology. A higher incidence rate of AA in the female population is well described. It is unclear why females are more likely to be diagnosed with AA and what, if any, differences in disease phenotype exist between males and females. The identification of gender specific characteristics of disease may help clinical management and patient education in cases of AA. Accordingly, we recruited 481 North-American Caucasian AA patients (336 female, 145 male) to assess age of onset, autoimmune and atopic co-morbidity, nail involvement, family history of AA and autoimmune disease, and disease subtype. There was a female predominance (female to male ratio 2.3:1) in this AA study population. We found that male AA patients are more likely to be diagnosed in childhood (age <10 years, P= 0.067) and have a family history of AA (P= 0.004). On the other hand, female AA patients are more likely to be diagnosed in adolescence (age 10-20 years, P= 0.083), have co-morbid nail involvement (P= 0.0257), and have concomitant autoimmune disease (P= 0.014), particularly thyroid disease (P= 0.058). The clinical implications of disease heterogeneity between males and females remains to be determined.

Unusual forms of alopecia areata in a Trichology Unit.

BACKGROUND: Alopecia areata (AA) occurs with the apparition of asyntomatic non inflamatory alopecia plaques without scars. We distinguish several variants which are divided into two groups: typical forms (AA in single or multiple plaques) and atypical forms (by its presentation, evolution or paradoxical regrowth). OBJETIVES AND METHODS: We describe the cases of AA treated in our Trichology Unit between January 2000 and December 2011. RESULTS: We obtained 488 cases of AA. 114 (23.36%) were unusual form of AA or had paradoxical regrowth. The most common unusual form of AA was sisaipho type (7.37%), followed by AA for black and blonde hair (5.32%), atypical diffuse forms (4.30%), androgenetic alopecia type and (3.89%) and AA rectangular occipital (0.68%). Furthermore, we found nine cases of paradoxical regrowth (1.84%). CONCLUSIONS: Atypical variants of AA in our series are less than 25% of all cases, although it should be noted that since it is a specialized unit, we may be making a selection bias to be more difficult to diagnose cases or poor outcome.

Comparison of interleukin-17- producing cells in different clinical types of alopecia areata.

T helper 17 cells, characterized by interleukin-17 (IL-17) production, play a critical role in the pathogenesis of autoimmune disease, including alopecia areata (AA). In this report, we employed immunohistochemical staining for IL-17-producing cells, as well as interferon-γ-producing cells, granulysin-bearing cells and Foxp3+ regulatory T cells, and performed a quantitative analysis of IL-17-producing cells in the lesional skin of several clinical forms of AA by TissueFAXS analysis. Among them, interestingly, the ratio of IL-17-producing cells in acute, diffuse and total alopecia was significantly lower than those of multiple types of AA. Our study sheds light on one of the possible immunological mechanisms of AA.

Acute diffuse and total alopecia: A new subtype of alopecia areata with a favorable prognosis.

BACKGROUND: Alopecia areata (AA) appears in several clinical forms, all having different clinical courses and different prognoses. Acute diffuse and total alopecia (ADTA) has been reported to have a short clinical course ranging from acute hair loss to total baldness, followed by rapid recovery. OBJECTIVE: To determine the clinical course and prognosis of ADTA through precise clinical observations. METHODS: Thirty Korean patients who showed ADTA of the scalp within an average of 10 weeks after the onset of hair loss were studied. RESULTS: Most patients were women who were older than 20 years of age. The histopathology of the lesion revealed infiltration of mononuclear cells around the hair follicles and prominent pigment incontinence. The patients experienced hair regrowth within about 6 months, without regard to the method of treatment. LIMITATIONS: The duration of follow-up after remission ranged from 3 to 49 months, with a mean of 24 months. CONCLUSIONS: These cases can be categorized as having "acute diffuse and total alopecia," a new subtype of AA that is associated with a favorable prognosis and rapid and spontaneous recovery even without treatment.

Cálvicie feminina: classificação proposta / Female baldness: proposal classification

O autor apresenta uma nova sugestão para classificar a calvície feminina, de forma mais didática e abrangente, possibilitando enquadrar as variações de casos clínicos encontrados na prática diária.

Profile of 513 patients with alopecia areata: associations of disease subtypes with atopy, autoimmune disease and positive family history.

BACKGROUND: Several lines of evidence support a genetic component to alopecia areata (AA), including differences in patients based on severity of AA, associated diseases and family history. OBJECTIVE: We aimed to examine clinical and genetic features of patients with AA with a focus on associated diseases, especially atopy, and family history of AA in the USA. METHODS: From 1998 to 2001, 513 patients with AA completed interviews consisting of demographic information, patient's medical history, and family history of AA. RESULTS: Forty per cent of respondents had alopecia totalis and/or universalis (AT/AU). These patients were younger at the age of onset than those with patchy AA (P < 0.001), were more likely to have associated autoimmune or atopic disease (P = 0.047), most notably atopic dermatitis (P = 0.021) and thyroid disease (P = 0.012). They also had a greater number of relatives affected by AA (P < 0.05). CONCLUSIONS: Our findings show marked associations between severity of AA, atopic dermatitis, thyroid disease and other autoimmune diseases, and extensive family history of AA, suggesting two clinically distinct subtypes of AA with the severe subtype possibly associated with greater familial autoimmunity. Further research exploring the possibility of a genetic basis to explain these clinical findings will be helpful in clarifying our understanding of AA, leading to improvements in diagnosis and treatment.