Noninvasive measures in atopic dermatitis

Atopic Dermatitis: Molecular Alterations between Lesional and Non-Lesional Skin Determined Noninvasively by In Vivo Confocal Raman Microspectroscopy

Atopic dermatitis (AD)/atopic eczema is a chronic relapsing inflammatory skin disease affecting nearly 14% of the adult population. An important pathogenetic pillar in AD is the disrupted skin barrier function (SBF). The atopic stratum corneum (SC) has been examined using several methods, including Raman microspectroscopy, yet so far, there is no depth-dependent analysis over the entire SC thickness. Therefore, we recruited 21 AD patients (9 female, 12 male) and compared the lesional (LAS) with non-lesional atopic skin (nLAS) in vivo with confocal Raman microspectroscopy. Our results demonstrated decreased total intercellular lipid and carotenoid concentrations, as well as a shift towards decreased orthorhombic lateral lipid organisation in LAS. Further, we observed a lower concentration of natural moisturising factor (NMF) and a trend towards increased strongly bound and decreased weakly bound water in LAS. Finally, LAS showed an altered secondary and tertiary keratin structure, demonstrating a more folded keratin state than nLAS. The obtained results are discussed in comparison with healthy skin and yield detailed insights into the atopic SC structure. LAS clearly shows molecular alterations at certain SC depths compared with nLAS which imply a reduced SBF. A thorough understanding of these alterations provides useful information on the aetiology of AD and for the development/control of targeted topical therapies.

Applications of Laser Speckle Contrast Imaging Technology in Dermatology

Laser speckle contrast imaging or laser speckle imaging (LSI) is a noninvasive imaging technology that can detect areas of dynamic perfusion or vascular flow. Thus, LSI has shown increasing diagnostic utility in various pathologies and has been employed for intraoperative, postoperative, and long-term monitoring in many medical specialties. Recently, LSI has gained traction in clinical dermatology because it can be effective in the assessment of pathologies that are associated with increased perfusion and hypervascularity compared with that of normal tissue. To date, LSI has been found to be highly accurate in monitoring skin graft reperfusion, determining the severity of burns, evaluating neurosurgical revascularization, assessing persistent perfusion in capillary malformations after laser therapy, and differentiating malignant and benign skin lesions. LSI affords the advantage of noninvasively assessing lesions before more invasive methods of diagnosis, such as tissue biopsy, while remaining inexpensive and exhibiting no adverse events to date. However, potential obstacles to its clinical use include tissue movement artifact, primarily qualitative data, and unclear impact on clinical practice given the lack of superiority data compared with the current standard-of-care diagnostic methods. In this review, we discuss the clinical applications of LSI in dermatology for use in the diagnosis and monitoring of vascular, neoplastic, and inflammatory skin conditions.

Atopic Dermatitis: From Etiology and History to Treatment

Atopic dermatitis (AD) is a chronic recurrent inflammatory skin disease in patients with atopy. Atopy itself, is defined as a predisposition to develop immune response with overproduction of immunoglobulin E to low doses of allergens. AD is one of the most common skin disorders in the developed world, affecting up to 20% of children and about 3% of adults. The pathogenesis of the disease is complex, with both genetic and environmental factors playing a significant role in it. Clinically, hallmarks of atopic dermatitis include dry, itchy skin and various cutaneous efflorescence, compatible to dermatitis or eczema. Atopic dermatitis subdivides into three morphological variants manifesting during infancy, childhood and adulthood. Various environmental factors and associated diseases may have serious influence on the clinical course or may trigger disease relapses. The aim of this review article is to serve as a comprehensive overview of the etiology, pathogenesis, clinical course and diagnosis, as well as potential challenges facing the successful treatment of atopic dermatitis.

Instrumental evaluation of skin barrier function and clinical outcomes during dupilumab treatment for atopic dermatitis: An observational study

BACKGROUND

Atopic dermatitis (AD) is a chronic, inflammatory skin disease characterized by pruritus, xerosis, and skin barrier dysfunction. Skin barrier alteration is associated with an increase in trans-epidermal water loss (TEWL) and reduction in skin hydration. Dupilumab is a monoclonal antibody targeting interleukin-13 modulating pro-inflammatory signal transduction, which has been approved for moderate to severe AD. The aim of this study is to evaluate the effects of Dupilumab on skin barrier functions, using non-invasive instruments and clinical evaluation.

MATERIALS AND METHODS

Thirty patients affected by moderate-severe AD, who had been administered dupilumab, were evaluated by clinical examination and through the instrumental measurements of TEWL and corneometry at the baseline (T0) and 8 weeks (T1) on lesional skin. The clinical evaluation was performed using the Eczema Area and Severity Index (EASI) score. Moreover, a Dermatology Life Quality Index (DLQI) and 7-day numeric rating scale (NRS) questionnaires were administered to each patient.

RESULTS

The instrumental parameters of skin barrier recovery confirmed the clinical improvement outcomes with a statistically significant reduction of TEWL at T1.

CONCLUSION

Our data confirm the clinical outcomes already reported in the literature and show that there was an inverse proportional correlation between TEWL levels and clinical severity after 8 weeks of treatment with dupilumab.

Assessing Biophysical and Physiological Profiles of Scalp Seborrheic Dermatitis in the Thai Population

Background

Scalp seborrheic dermatitis (SD) is a common and chronic inflammatory skin disease which tends to recur over time. By measuring biophysical properties of the stratum corneum, many studies report abnormal biophysical profiles and their association in various dermatologic diseases. The aim of the study is to analyze the biophysical properties and skin barrier defects of scalp SD compared to healthy controls.

Materials and Methods

This study is a cross-sectional study assessing the correlation of various biophysical and physiological profiles in scalp SD. Forty-two Thai participants with scalp SD were enrolled in the study and 40 healthy participants were also enrolled as the control group. Both SD and control group were subjected to a one-time biophysical and physiological properties' measurement of transepidermal water loss (TEWL), stratum corneum hydration (SCH), skin surface pH, skin surface lipid, and skin roughness.

Results

The mean TEWL of lesional skin of SD cases were significantly higher than those of control group (P<0.05). Relating to high mean TEWL, the mean SCH was found to be significantly lower in SD cases (P<0.05). Skin surface lipid was also found to be significantly higher in SD group (P<0.05). However, there were no differences in skin surface pH (P=0.104) and roughness (P=0.308) between the two groups. Pairwise comparison of each subgroup found that moderate and severe SD demonstrated significantly higher mean skin surface lipid than that of control group (P<0.05).

Conclusion

Scalp SD may be associated with seborrhea in Thai population. Monitoring of SCH, TEWL, and skin surface lipid could be helpful in assessing severity and evaluating the treatment outcome in patients with scalp SD.