Dermoscopic features of pseudoxanthoma elasticum

Dermoscopic Patterns of Genodermatoses: A Comprehensive Analysis

(1) Background: Genodermatoses are a clinically and genetically heterogenous group of inherited skin disorders. Diagnosing inherited skin diseases is a challenging task due to their rarity and diversity. Dermoscopy is a non-invasive, easily accessible, and rapid tool used in dermatology not only for diagnostic processes but also for monitoring therapeutic responses. Standardized terminologies have been published for its proper use, reproducibility, and comparability of dermoscopic terms. (2) Methods: Here, we aimed to investigate dermoscopic features in various genodermatoses by conducting a systematic review and comparing its results to our own findings, data of patients diagnosed with genodermatoses at the Department of Dermatology, Venereology and Dermatooncology, Semmelweis University. (3) Results: Our systematic search provided a total of 471 articles, of which 83 reported both descriptive and metaphoric dermoscopic terminologies of 14 genodermatoses. The literature data were then compared to the data of 119 patients with 14 genodermatoses diagnosed in our department. (4) Conclusion: Dermoscopy is a valuable tool in the diagnosis of genodermatoses, especially when symptoms are mild. To enable the use of dermoscopy as an auxiliary diagnostic method, existing standardized terminologies should be extended to more genodermatoses.

[Dermoscopy of genodermatoses]

Genodermatoses are a group of inherited skin diseases whose diagnosis is challenging due to their rarity as well as their clinical and genetic diversity. The majority of genodermatoses are autosomal or X‑linked inherited, but mosaic forms are also observed. Genodermatoses comprise various phenotypes ranging from limited cutaneous disease to severe cutaneous and extracutaneous involvement and may also be early warning signs of a multisystemic disorder. Despite recent advances in genetic technology and skin imaging modalities, dermoscopy can be useful for screening, diagnosis, and treatment follow-up. In ectopic mineralization and lysosomal storage disorders (pseudoxanthoma elasticum and Fabry disease, respectively), cutaneous manifestations may indicate involvement of other organs. In keratinization diseases (e.g., ichthyoses) and acantholytic skin fragility disorders (e.g., Darier and Hailey-Hailey disease), dermoscopy may help to assess treatment response by visualizing background erythema, hyperkeratosis, and interkeratinocyte space prominence. Dermoscopy is a noninvasive, easily accessible, useful, in vivo assessment tool that is well established in dermatology to recognize characteristic features of genodermatoses.

A case report: pseudoxanthoma elasticum diagnosed based on ocular angioid streaks and the curative effect of Conbercept treatment

Background

This article is a case report of pseudoxanthoma elasticum (PXE) which was diagnosed based on significant angioid streaks (AS) with choroidal neovascularization (CNV) and regain normal visual function by intravitreal injection with Conbercept.

Case presentation

A 51-year-old woman was referred to the Ophthalmology Department of Qingdao Municipal Hospital (Qingdao, China) on September 14, 2020 for metamorphopsia and loss of vision in the left eye in the preceding three days. Past history: high myopia for more than 30 years, best corrected visual acuity (BCVA) of both eyes was 1.0 (5 m Standard Logarithm Visual Acuity chart in decimal notations), hypertension for six years, and cerebral infarction two years ago, no history of ocular trauma or surgeries or similar patients in family was documented. We used methods for observation, including fundus examination, optical coherence tomography (OCT), fluorescein angiography combined with indocyanine green angiography (FFA + ICGA). Due to her symptoms and manifestations, along with the appearance of her neck skin, which resembled ‘chicken skin’, we speculated that she should be further examined at the Department of Dermatology by tissue paraffin section and molecular pathology analyses, and the diagnosis of PXE was then confirmed. After intravitreal injection with Conbercept (10 mg/ml, 0.2 ml, Chengdu Kanghong Biotechnologies Co., Ltd.; Chengdu, Sichuan, China) she regained her BCVA.

Conclusions

This patient regained her best corrected visual acuity through intravitreal injection with Conbercept. To the best of our knowledge, no publications are available on cases in which a vision loss and the normal visual function can be reverted by intravitreal injection with Conbercept. Although PXE is a disease with low incidence and thus no effective cure established, targeted symptomatic treatment can effectively retard the disease progression and improve visual function, such as intravitreal injection with Conbercept.

Autofluorescence Imaging of the Skin Is an Objective Non-Invasive Technique for Diagnosing Pseudoxanthoma Elasticum

Pseudoxanthoma elasticum (PXE) is a rare multisystemic autosomal recessive connective tissue disease. In most cases, skin manifestations of PXE are the first to develop, followed later by severe ocular and cardiovascular complications. In our present study, in addition to dermoscopy, we introduced novel techniques, autofluorescence (AF) and diffuse reflectance (DR) imaging for the assessment of affected skin sites of five PXE patients. PXE-affected skin areas in most skin sites showed a previously observed pattern upon dermoscopic examination. With the novel imaging, PXE-affected skin lesions displayed high AF intensity. During our measurements, significantly higher mean, minimum and maximum AF intensity values were found in areas of PXE-affected skin when compared to uninvolved skin. Conversely, images acquired with the use of 660 and 940 nm illumination showed no mentionable difference. Our results demonstrate that AF imaging may be used in the in vivo diagnostics and quantification of the severity of the skin lesions of PXE patients. In addition, it is a safe, fast and cost-effective diagnostic method. AF imaging may be also used to objectively monitor the efficacy of the possible novel therapeutic approaches of PXE in the future.

Bidimensional Multiscale Fuzzy Entropy and Its Application to Pseudoxanthoma Elasticum

OBJECTIVE

We propose a new bidimensional entropy measure and its multiscale form and evaluate their behavior using various synthetic and real images. The bidimensional multiscale measure finds application in helping clinicians for pseudoxanthoma elasticum (PXE) detection in dermoscopic images.

METHOD

We developed bidimensional fuzzy entropy ( FuzEn_2D) and its multiscale extension ( MSF_2D) and then evaluated them on a set of synthetic images and texture datasets. Afterwards, we applied MSF_2D to dermoscopic PXE images and compared the results to those obtained by bidimensional multiscale sample entropy ( MSE_2D).

RESULTS

The results for the synthetic images illustrate that FuzEn_2D has the ability to quantify images irregularity. Moreover, FuzEn_2D, compared with bidimensional sample entropy ( SampEn_2D), leads to more stable results. The tests with the multiscale version show that MSF_2D is a proper image complexity measure. When applied to the dermoscopic PXE images, the paired t-test illustrates a significant statistical difference between MSF_2D of neck images with papules and normal skin images at a couple of scale factors.

CONCLUSION

The results for the synthetic data illustrate that FuzEn_2D is an image irregularity measure that overcomes SampEn_2D in terms of reliability, especially for small-sized images, and stability of results. The results for the PXE dermoscopic images demonstrate the ability of MSF_2D to recognize dermoscopic images of normal zones from PXE papules zones with a large effect size.

SIGNIFICANCE

This work introduces new image irregularity and complexity measures and shows the potential for MSF_2D to serve as a possible tool helping medical doctors in PXE diagnosis.