Pilot study on the sensitivity and specificity of in vivo reflectance confocal microscopy in the diagnosis of allergic contact dermatitis

High-speed reflectance confocal microscopy using speckle modulation

We developed a spectrally-encoded, line reflectance confocal microscope (RCM) that uses a rotating diffuser to rapidly modulate the illumination speckle pattern. The speckle modulation approach reduced speckle noise while imaging with a spatially coherent light source needed for high imaging speed and cellular resolution. The speckle-modulation RCM device achieved lateral and axial resolutions of 1.1 µm and 2.8 µm, respectively. With an imaging speed of 107 frames/sec, three-dimensional RCM imaging over 300-µm depth was completed within less than 1 second. RCM images of human fingers, forearms, and oral mucosa clearly visualized the characteristic cellular features without any noticeable speckle noise.

Reflectance Confocal Microscopy in Monitoring Atopic Dermatitis Treated with Topical Calcineurin Inhibitors

Atopic dermatitis is a chronic inflammatory skin disease associated with multiple allergies in the atopic march. It has a complex pathogenesis, related to genetic, immune, and environmental factors. Its incidence and prevalence are increasing in the last decades, especially in developed countries. It affects the quality of life due to the recurrent lesions and the associated pruritus. Thus, it is very important to use non-invasive techniques to manage and follow-up the patients with such a heterogenous disease that can have a high impact on some of them. The reflectance confocal microscope is a modern device for in vivo visualization of the epidermis and the upper dermis which could replace in some cases the cutaneous biopsy. We report a case of a patient with atopic dermatitis investigated with the confocal reflectance microscope at the beginning of the topical treatment with calcineurin inhibitors and three weeks after, with favorable evolution. Reflectance confocal microscopy allows the assessment of the dynamic changes in the skin during treatment. Moreover, it can be useful for highlighting discrete changes even in the subclinical stages of the inflammatory process. Future developments, which will lead to the definition and validation of reflectance confocal microscopy criteria for the diagnosis and staging of atopic dermatitis, could help to improve the treatment and prevention strategies of the disease.

Optical coherence tomography

During the past decade, noninvasive imaging has emerged as a valuable tool in clinical dermatology and dermatologic research. Optical coherence tomography (OCT) is one such type of noninvasive imaging. OCT uses the principle of interferometry to produce real-time images. A low-power diode laser shines infrared light onto tissues, which reflects back to an optical fiber interferometer. Using time delay and the backscattered light intensity, a two-dimensional image akin to an ultrasound is rendered. We review the history, types, and modalities of OCT, plus the many applications of frequency domain, high definition, and dynamic OCT in practice, including its utility in diagnosis, monitoring, and grading disease severity in a variety of cutaneous conditions.

Skin erythema assessment techniques

Skin erythema may present owing to many causes. One of the common causes is prolonged exposure to sunrays. Other than sun exposure, skin erythema is an accompanying sign of dermatologic diseases, such as psoriasis and acne. Quantifying skin erythema in patients enables the dermatologist to assess the patient's skin health. Quantitative assessment of skin erythema has been the focus of several studies. The clinical standard for erythema evaluation is visual assessment; however, this standard has some deficiencies. For instance, visual assessment is subjective and ineffectual for precise color information exchange. To overcome these limitations, in the past three decades various methodologies have been developed in an attempt to achieve objective erythema assessments, such as diffuse reflectance spectroscopy and both optical and nonoptical systems. This review considers the studies published during the past three decades and discusses the performance, the mathematical tactics for computation, and the limited capabilities of erythema assessment techniques for cutaneous diseases. The achievements and limitations of the current techniques in erythema assessment are presented. The advantages and development trends of optical and nonoptical methods are presented to make the reader aware of the present technological advances and their potential for dermatological disease research.

Reflectance Confocal Microscopy, Optical Coherence Tomography, and Multiphoton Microscopy in Inflammatory Skin Disease Diagnosis

BACKGROUND AND OBJECTIVES

Technological advances in medicine have brought about many novel skin imaging devices. This review aims to evaluate the scientific evidence supporting the use of noninvasive optical imaging techniques to aid in the diagnosis and prognosis of inflammatory skin diseases.

STUDY DESIGN/MATERIALS AND METHODS

PubMed and Scopus were searched in September 2020 according to PRISMA guidelines for articles using reflectance confocal microscopy (RCM), optical coherence tomography (OCT), and multiphoton microscopy (MPM) in inflammatory skin diseases, excluding studies monitoring treatment efficacy.

RESULTS

At the time of the study, there were 66 articles that addressed the utilization of noninvasive imaging in interface, spongiotic, psoriasiform, vesiculobullous, and fibrosing/sclerosing inflammatory skin dermatoses: RCM was utilized in 46, OCT in 16, and MPM in 5 articles. RCM was most investigated in psoriasiform dermatoses, whereas OCT and MPM were both most investigated in spongiotic dermatoses, including atopic dermatitis and allergic contact dermatitis.

CONCLUSIONS

There is preliminary evidence to support the diagnostic potential of noninvasive optical imaging techniques in inflammatory skin diseases. Improvements in the devices and further correlation with histology will help broaden their utility. Additional studies are needed to determine the parameters for diagnostic features, disease differentiation, and staging of inflammatory skin conditions. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

A Clinical Perspective on the Automated Analysis of Reflectance Confocal Microscopy in Dermatology

BACKGROUND AND OBJECTIVES

Non-invasive optical imaging has the potential to provide a diagnosis without the need for biopsy. One such technology is reflectance confocal microscopy (RCM), which uses low power, near-infrared laser light to enable real-time in vivo visualization of superficial human skin from the epidermis down to the papillary dermis. Although RCM has great potential as a diagnostic tool, there is a need for the development of reliable image analysis programs, as acquired grayscale images can be difficult and time-consuming to visually assess. The purpose of this review is to provide a clinical perspective on the current state of artificial intelligence (AI) for the analysis and diagnostic utility of RCM imaging.

STUDY DESIGN/MATERIALS AND METHODS

A systematic PubMed search was conducted with additional relevant literature obtained from reference lists.

RESULTS

Algorithms used for skin stratification, classification of pigmented lesions, and the quantification of photoaging were reviewed. Image segmentation, statistical methods, and machine learning techniques are among the most common methods used to analyze RCM image stacks. The poor visual contrast within RCM images and difficulty navigating image stacks were mediated by machine learning algorithms, which allowed the identification of specific skin layers.

CONCLUSIONS

AI analysis of RCM images has the potential to increase the clinical utility of this emerging technology. A number of different techniques have been utilized but further refinements are necessary to allow consistent accurate assessments for diagnosis. The automated detection of skin cancers requires more development, but future applications are truly boundless, and it is compelling to envision the role that AI will have in the practice of dermatology. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

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

BACKGROUND

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.

OBJECTIVES

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).

METHODS

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.

RESULTS

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).

LIMITATIONS

Small sample size, open study, imaging sampling bias.

CONCLUSION

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.

In Vivo Reflectance Confocal Microscopy: Emerging Role in Noninvasive Diagnosis and Monitoring of Eczematous Dermatoses

Dermatologic diagnosis and monitoring have been dependent largely on visual grading. A skin biopsy is performed in case of diagnostic uncertainty, but can be traumatic, and results are delayed due to time for specimen transport and processing. Biopsies also destroy specimens, prohibiting lesion evolution monitoring. In vivo reflectance confocal microscopy (RCM) offers a diagnostic alternative to skin biopsy. RCM captures real-time, high-resolution images, and has been piloted for the evaluation of various dermatologic conditions. Identification of unique RCM features may distinguish dermatoses with similar clinical morphologies. Allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) are diagnosed by patch testing that currently uses a subjective scoring system. RCM has increasingly been studied for early detection and severity grading of CD. Common RCM features shared by ACD and ICD are stratum corneum disruption, vesicle formation, exocytosis, spongiosis, and parakeratosis. Features unique to ACD are vasodilation, increased epidermal thickness, intercellular edema, and acanthosis. Features unique to ICD are detached corneocytes and targetoid keratinocytes. This review summarizes the use of RCM in evaluating contact eccematous conditions and aims to spark future research and interest in this promising tool.

Classification of established atopic dermatitis in children with the in vivo imaging methods

Atopic dermatitis (AD) is a cutaneous disease resulting from a defective barrier and dysregulated immune response. The severity scoring of atopic dermatitis (SCORAD) is used to classify AD. Noninvasive imaging approaches supplementary to SCORAD were investigated. Cr:forsterite laser-based microscopy was employed to analyze endogenous third-harmonic generation (THG) and second-harmonic generation (SHG) signals from skin. Imaging parameters were compared between different AD severities. Three-dimensional reconstruction of imaged skin layers was performed. Finally, statistic models from quantitative imaging parameters were developed for predicting disease severity. Our data demonstrate that THG signal intensity of lesional skin in AD were significantly increased and was positively correlated with AD severity. Characteristic gray level co-occurrence matrix (GLCM) values were observed in more severe AD. In the 3D reconstruction video, individual dermal papilla and obvious fibrosis in the upper papillary dermis were easily identified. Our estimation models could predict the disease severity of AD patients with an accuracy of nearly 85%. The THG signal intensity and characteristic GLCM patterns are associated with AD severity and can serve as quantitative predictive parameters. Our imaging approach can be used to identify the histopathological changes of AD objectively, and to complement the SCORAD index, thus improving the accuracy of classifying AD severity.

Noninvasive measures in atopic dermatitis

PURPOSE OF REVIEW

To summarize the current knowledge on the morphology, functionality and biochemical composition of the skin in allergic reactions. We address novel noninvasive techniques that promise to disclose intimate mechanisms of skin allergy in vivo. Epidermal barrier is not just a static wrap of the organism but rather a dynamic field for immunological, biophysical and biochemical processes and serves as a bio-sensor for exogenous danger signals.

RECENT FINDINGS

Classical biophysical methods are amended by novel in-vivo techniques, such as Raman spectroscopy, analysing the skin microcomposition and develop epidermal profiles. Visualization techniques, such as reflectance spectroscopy and optical coherence tomography (OCT) are employed in studying the micro-morphological changes in the skin of allergic patients.

SUMMARY

The noninvasive assessment of skin functions, micro-morphology and biochemical as well as immunological pathways will help to better understand skin allergies. They will allow to detect subtypes, for example in atopic dermatitis and to develop specific treatment modalities.

Monitoring treatment response in psoriasis: current perspectives on the clinical utility of reflectance confocal microscopy

Reflectance confocal microscopy (RCM) evaluation of inflammatory skin diseases represents a relatively new technique that, during the past 5 years, has attracted increasing interest, with consequent progressive increment of publications in literature. The success of RCM is directly related to the high need for noninvasive techniques able to both reduce the number of skin biopsies and support clinical diagnosis and patient management. RCM helps to visualize microscopic descriptors of plaque psoriasis (PP) with good reproducibility between observers and a high grade of correspondence with histopathology. Several clinical tests are used for the therapeutic management of PP, but they are limited by subjective interpretation. Skin biopsy presents objective interpretation, but the procedure is invasive and not repeatable. RCM has been used not only for the evaluation of skin cancer or inflammatory skin diseases, but also for monitoring the efficacy of different treatments in PP. In this review, we present some examples of RCM applications in therapeutic psoriasis follow-up.

Reflectance confocal microscopy of skin in vivo: From bench to bedside

Following more than two decades of effort, reflectance confocal microscopy (RCM) imaging of skin was granted codes for reimbursement by the US Centers for Medicare and Medicaid Services. Dermatologists in the USA have started billing and receiving reimbursement for the imaging procedure and for the reading and interpretation of images. RCM imaging combined with dermoscopic examination is guiding the triage of lesions into those that appear benign, which are being spared from biopsy, against those that appear suspicious, which are then biopsied. Thus far, a few thousand patients have been spared from biopsy of benign lesions. The journey of RCM imaging from bench to bedside is certainly a success story, but still much more work lies ahead toward wider dissemination, acceptance, and adoption. We present a brief review of RCM imaging and highlight key challenges and opportunities. The success of RCM imaging paves the way for other emerging optical technologies, as well-and our bet for the future is on multimodal approaches. Lasers Surg. Med. 49:7-19, 2017. © 2016 Wiley Periodicals, Inc.

Reflectance confocal microscopy for monitoring the density of Demodex mites in patients with rosacea before and after treatment

BACKGROUND

Demodex mites seem to serve as a pathogenic trigger in many Demodex-associated diseases such as rosacea. In facial skin of patients with rosacea significantly higher numbers of Demodex mites have been shown compared with healthy controls. Reflectance confocal microscopy (RCM) allows the detection and quantification of Demodex mites in vivo noninvasively. It is hypothesized that a reduction of Demodex mites under rosacea therapy can be monitored by RCM.

OBJECTIVES

To use RCM to monitor the density of Demodex mites in patients with rosacea before and after treatment.

METHODS

In 25 patients with facial rosacea RCM was performed before and after therapy. Mosaics of 5 × 5 mm(2) and 8 × 8 mm(2) were scanned, and the total numbers of mites per follicle and per area were counted, along with the number of follicles per area.

RESULTS

In all patients Demodex folliculorum could be detected and quantified using RCM. RCM showed significant differences pre- and post-treatment (P = 0.0053 for 5 × 5 mm(2) and P < 0.001 for 8 × 8 mm(2)). The mean numbers of mites per follicle were 0.63 (range 0.16-2.28) per 8 × 8 mm(2) area and 0.70 (range 0.11-2.20) per 5 × 5 mm(2) area before treatment, and 0.41 (range 0.074-1.75) and 0.51 (range 0.094-1.70), respectively, after treatment. The corresponding mean numbers of mites were 155 (range 45-446) and 86.2 (range 12-286), respectively, before treatment and 96.2 (range 18-363) and 58.5 (range 12-230), respectively, after treatment.

CONCLUSIONS

By RCM, a reduction in the density of Demodex mites in facial skin of patients with rosacea under therapy, correlating to clinical improvement, can be quantified and monitored noninvasively. Possible reasons for this therapeutic effect are discussed.

Review of allergic contact dermatitis: Scratching the surface

Contact dermatitis-including allergic contact dermatitis (ACD)-n and results in over four million lost work days per year in the United States alone. ACD is a classic example of a type IV delayed hypersensitivity reaction, and represents a significant burden on the health system, economy, and patient quality of life. Thorough history taking, clinical examination, histologic evaluation, and patch testing are keys to diagnosing contact dermatitis. Patch testing, especially with comprehensive and customized panels based on the patient’s exposure history, is particularly useful in identifying potential allergens in the case of allergic contact dermatitis. ACD management requires a combination of direct medical intervention, patient education, and appropriate environmental modification to prevent exposure to offending allergens in the home or workplace. Continuing advances in the study of ACD has led to an increased understanding of the disease processes, new methods for diagnosis, and improved management. This article reviews ACD-aiming to connect recent investigational data with the current clinical understanding of disease pathophysiology, diagnostic techniques, and management strategies.

Pathogenesis and diagnosis of contact dermatitis: Applications of reflectance confocal microscopy

Contact dermatitis (CD) is the most common professional skin disease, with frequencies ranging from 24 to 170 every 100000 individuals. Approximately 20% of the United States population suffers from CD. CD can be classified according to its origin and severity. ICD stands for irritant CD, whereas ACD means allergic CD. Their clinical presentation includes acute, sub-acute and chronic eczema. Despite their different origin, ICD and ACD often present similar clinical and histologic findings. The current gold standard for diagnosis is patch-testing. However, patch-testing is being questioned in terms of validity and reproducibility, as it relies heavily on the skill of the observer. Real-time reflectance confocal microscopy is a non-invasive imaging technique that bears strong promise for the study of CD, and it enables the evaluation of cellular and subcellular changes over time with similar resolution compared to that of conventional histology.

Reflectance confocal microscopy vs. standardized skin surface biopsy for measuring the density of Demodex mites

BACKGROUND

Reflectance confocal microscopy (RCM) has been recently shown to be effective for measuring the Demodex mite density.

OBJECTIVES

To compare and demonstrate the advantages and disadvantages of standardized skin surface biopsy (SSSB) and RCM for measuring the density of Demodex mites.

MATERIALS AND METHODS

Forty-eight patients (30 female, 18 male) and 47 healthy controls (30 female, 17 male) were enrolled in the study. The patients diagnoses were pityriasis folliculorum (n = 40), papulopustulary rosecea (n = 7) and erythema-telengiectatic rosacea (n = 1). The area with the most intense erythema on the right cheek was selected for imaging with RCM (VivaScope 3000) and SSSB.

RESULTS

Forty-two patients demonstrated high Demodex density [(Dd) > 5 mites/cm(2) ] with SSSB (85.7%). RCM identified demodicosis in 48 patients (100%). The mean Dd measured with RCM (409.8 ± 209.2) was significantly higher than SSSB (15.33 ± 18.1) (P < 0.001). In the patients, RCM demonstrated the mean number of mites 40.90 ± 20.9 and 4.11 ± 6.4 in the controls per 10 mm(2) area. The corresponding mean number of 2.63 ± 0.77 mites was detected in the infested follicles per area of view compared to a mean of 0.77 ± 0.98 mites in the infested follicles in the controls (P < 0.001).

CONCLUSION

Reflectance confocal microscopy is a fast, direct and noninvasive method for Demodex-associated diseases and it is superior to SSSB for Demodex mite detection.

Noninvasive in vivo detection and quantification of Demodex mites by confocal laser scanning microscopy

BACKGROUND

In many Demodex-associated skin diseases Demodex mites are present in abundance and seem to be at least partially pathogenic. So far all diagnostic approaches such as scraping or standardized superficial skin biopsy are (semi-)invasive and may cause discomfort to the patient.

OBJECTIVES

To see whether confocal laser scanning microscopy (CLSM) - a noninvasive method for the visualization of superficial skin layers - is able to detect and quantify D. folliculorum in facial skin of patients with rosacea.

METHODS

Twenty-five patients (34-72 years of age) with facial rosacea and 25 age- and sex-matched normal controls were examined by CLSM. Mosaics of 8 × 8 mm and 5 × 5 mm were created by scanning horizontal layers of lesional skin and quantification of mites per follicle and per area as well as follicles per area was performed.

RESULTS

In all patients D. folliculorum could be detected by CLSM and presented as roundish or lengthy cone-shaped structures. CLSM allowed the quantification of Demodex mites and revealed significant differences (P < 0·0001): the mean number of mites was 165·4 per 8 × 8 mm area and 94·2 per 5 × 5 mm area in the patients compared with 34·7 and 22·4, respectively, in the controls. The corresponding mean number of mites per follicle was 0·7 and 0·8, respectively, in the patients and 0·1 and 0·2, respectively, in the controls.

CONCLUSIONS

With the help of CLSM it is possible to detect, image and quantify Demodex mites noninvasively in facial skin of patients with rosacea.

High-definition optical coherence tomography: adapted algorithmic method for pattern analysis of inflammatory skin diseases: a pilot study

High-definition optical coherence tomography (HD-OCT) is a non-invasive technique for morphological investigation of tissue with cellular resolution filling the imaging gap between reflectance confocal microscopy and conventional optical coherence tomography. The aim of this study is first to correlate dermatopathologic descriptors of inflammatory skin conditions with epidermal alteration to features observed by HD-OCT. Secondly, to assess the discriminative accuracy of common inflammatory reaction patterns with epidermal alteration using HD-OCT by applying Ackerman’s algorithmic method of pattern recognition. The generated HD-OCT images of 160 patients presenting an inflammatory skin disease were analyzed with respect to the following criteria: visualization of individual cells in the epidermis and dermis and morphology of dermo-epidermal junction, papillary dermis and reticular dermis. A set of morphological features corresponding to dermatopathological descriptors are obtained and the discriminative accuracy of HD-OCT of inflammatory reaction patterns could be demonstrated. These patterns are spongiotic dermatitis, psoriasiform dermatitis, interface dermatitis and ballooning dermatitis. Additional studies to test the sensitivity and specificity of the proposed algorithm for pattern analysis are essential. The other categories of Ackerman’s pattern recognition need to be evaluated. This study provides a set of morphological features generated by HD-OCT imaging very similar to those described for reflectance confocal microscopy but with the advantages not only to visualize individual cells up to a depth of 570 μm but also in both slice and en face mode. An adapted algorithmic method for pattern analysis of common inflammatory skin diseases could be proposed. This new technique appears to be a promising method for non-invasive diagnosis, evaluation and management of common inflammatory skin diseases.

Evaluation of reflectance confocal microscopy in dermatophytosis

Traditional diagnostic testing for dermatophyte infection currently requires skin scraping for light microscopy and/or fungal culture or skin biopsy. Immunofluorescent microscopy can also be used with calcofluor stain. All of these tests can be time-consuming to perform, require a waiting period for results and are invasive. This study aimed to define the in vivo reflectance confocal microscopy (RCM) features of superficial cutaneous fungal infections and to analyse concordance with microscopic examination. Totally, 45 patients, who were diagnosed with superficial cutaneous fungal infections according to the positive result of microscopic examination, were enrolled in this study. We selected three typical lesions examined by RCM, and then recorded the results. In the patients with the tinea manus and pedis, mycelium in stratum corneum was found by the RCM in 14 of 22 patients (14/22; 63.64%). In the patients with the tinea cruris, mycelium in stratum corneum was found by the RCM in 19 of 23 patients (19/23; 82.61%). RCM seems to be useful for microscopic evaluation of mycelium features and may have a scientific value in study of superficial cutaneous fungal infections.

Consistency and distribution of reflectance confocal microscopy features for diagnosis of cutaneous T cell lymphoma

Reflectance confocal microscopy (RCM) represents a noninvasive imaging technique that has previously been used for characterization of mycosis fungoides (MF) in a pilot study. We aimed to test the applicability of RCM for diagnosis and differential diagnosis of MF in a clinical study. A total of 39 test sites of 15 patients with a biopsy-proven diagnosis of either MF, parapsoriasis, Sézary syndrome, or lymphomatoid papulosis were analyzed for presence and absence of RCM features of MF. Cochran and Chi(2) analysis were applied to test the concordance between investigators and the distribution of RCM features, respectively. For selected parameters, the Cochran analysis showed good concordance between investigators. Inter-observer reproducibility was highest for junctional atypical lymphocytes, architectural disarray, and spongiosis. Similarly, Chi(2) analysis demonstrated that selected features were present at particularly high frequency in individual skin diseases, with values ranging from 73% to 100% of all examined cases.

Visualization of plasmid delivery to keratinocytes in mouse and human epidermis

The accessibility of skin makes it an ideal target organ for nucleic acid-based therapeutics; however, effective patient-friendly delivery remains a major obstacle to clinical utility. A variety of limited and inefficient methods of delivering nucleic acids to keratinocytes have been demonstrated; further advances will require well-characterized reagents, rapid noninvasive assays of delivery, and well-developed skin model systems. Using intravital fluorescence and bioluminescence imaging and a standard set of reporter plasmids we demonstrate transfection of cells in mouse and human xenograft skin using intradermal injection and two microneedle array delivery systems. Reporter gene expression could be detected in individual keratinocytes, in real-time, in both mouse skin as well as human skin xenografts. These studies revealed that non-invasive intravital imaging can be used as a guide for developing gene delivery tools, establishing a benchmark for comparative testing of nucleic acid skin delivery technologies.

In vivo reflectance confocal microscopy: usefulness for diagnosing hair diseases

BACKGROUND

Reflectance confocal laser scanning microscopy (R-CSLM) is a new diagnostic technique which allows visualization of "optical intersections" within the epidermis and superficial layers of the dermis. Outlines of cells and their architecture are imaged and may be analyzed both horizontally and vertically to the skin surface. The method proved useful in early melanoma detection. We evaluated the potential usefulness of this method in a short series of patients with hair diseases.

MAIN OBSERVATIONS

Two healthy persons and 6 patients with hair diseases (1 with alopecia areata, 1 with androgenic alopecia and 4 with genetic hair shaft abnormalities) were examined with the use of Vivascope 1500. In all patients one scalp location and one location in the mid forearm were evaluated. R-CSLM examination gave in all cases high quality images of the hair shaft intersections, at 1µm intervals, which allowed detailed analysis of the hair structure. Hair follicles could be partly visualized at a depth of up to 200µm, which allowed analysis of only superficial parts of the hair follicles. An additional hurdle was bright reflection within the follicular ostia, which decreased the perception of details in these images. Hair could be best visualized, when analyzed on flat surfaces. Receiving good quality images from convex surfaces on the scalp required additional effort from the patient (to not move) and from the physician (to obtain best possible fit of the "optic window" to the scalp).

CONCLUSIONS

These preliminary data show that R-CSLM may develop into a valuable tool in evaluation of hair shaft diseases. Further development is needed to apply this technique in abnormalities of the hair follicle and the perifollicular area.

Confocal microscopic features of scarring alopecia: preliminary report

BACKGROUND

Lichen planopilaris (LPP) and discoid lupus erythematosus (DLE) are the most common causes of lymphocytic primary cicatricial alopecia. The management of scarring alopecia can be difficult. The combination of clinical, dermoscopy and reflectance confocal microscopy (RCM), a noninvasive, high-resolution imaging technique, examinations have already been demonstrated to be useful for choosing the correct biopsy site in patients with inflammatory skin disease and obtaining microscopic diagnostic criteria.

OBJECTIVES

We evaluated the usefulness in practice of RCM for the identification of criteria for LPP and DLE involving the scalp and their management during therapeutic follow-up.

METHODS

Seven white patients with a previously established histological diagnosis of DLE (three) and LPP (four), were included in the study. RCM criteria for primary scarring alopecia were selected: epidermal disarray, spongiosis, exocytosis of inflammatory cells in the epidermis, interface dermatitis, peri- and intra-adnexal infiltration of inflammatory cells, dilated vessels in the dermis, dermal infiltration of inflammatory cells and melanophages and dermal sclerosis. All patients were followed up using RCM during the treatment. During follow-up the RCM evolution of the epidermal, junctional and dermal inflammation were evaluated.

RESULTS

A series of RCM features of scalp LPP and DLE were identified that show correlation with the histopathological evaluation. During the treatment follow-up of the cases RCM was shown to be sensitive for the identification of therapeutic response.

CONCLUSION

In our preliminary study the effective usefulness of RCM for the diagnosis of scarring alopecia and follow-up seemed to be evident. Moreover, RCM seems to be also promising for differential diagnosis between the different entities.