Skin manifestations of COVID-19 in children: Part 3.

The current COVID-19 pandemic is caused by the SARS-CoV-2 coronavirus. The initial recognized symptoms were respiratory, sometimes culminating in severe respiratory distress requiring ventilation, and causing death in a percentage of those infected. As time has passed, other symptoms have been recognized. The initial reports of cutaneous manifestations were from Italian dermatologists, probably because Italy was the first European country to be heavily affected by the pandemic. The overall clinical presentation, course and outcome of SARS-CoV-2 infection in children differ from those in adults as do the cutaneous manifestations of childhood. In this review, we summarize the current knowledge on the cutaneous manifestations of COVID-19 in children after thorough and critical review of articles published in the literature and from the personal experience of a large panel of paediatric dermatologists in Europe. In Part 1, we discuss one of the first and most widespread cutaneous manifestations of COVID-19, chilblain-like lesions, and in Part 2 we expanded to other manifestations, including erythema multiforme, urticaria and Kawasaki disease-like inflammatory multisystemic syndrome. In this part of the review, we discuss the histological findings of COVID-19 manifestations, and the testing and management of infected children for both COVID-19 and any other pre-existing conditions.

Skin manifestations of COVID-19 in children: Part 2.

The current COVID-19 pandemic is caused by the SARS-CoV-2 coronavirus. The initial recognized symptoms were respiratory, sometimes culminating in severe respiratory distress requiring ventilation, and causing death in a percentage of those infected. As time has passed, other symptoms have been recognized. The initial reports of cutaneous manifestations were from Italian dermatologists, probably because Italy was the first European country to be heavily affected by the pandemic. The overall clinical presentation, course and outcome of SARS-CoV-2 infection in children differ from those in adults, as do the cutaneous manifestations of childhood. In this review, we summarize the current knowledge on the cutaneous manifestations of COVID-19 in children after thorough and critical review of articles published in the literature and from the personal experience of a large panel of paediatric dermatologists in Europe. In Part 1, we discussed one of the first and most widespread cutaneous manifestations of COVID-19, chilblain-like lesions. In this part of the review, we describe other manifestations, including erythema multiforme, urticaria and Kawasaki disease-like inflammatory multisystemic syndrome. In Part 3, we discuss the histological findings of COVID-19 manifestations, and the testing and management of infected children for both COVID-19 and any other pre-existing conditions.

Skin manifestations of COVID-19 in children: Part 1.

The current COVID-19 pandemic is caused by the SARS-CoV-2 coronavirus. The initial recognized symptoms were respiratory, sometimes culminating in severe respiratory distress requiring ventilation, and causing death in a percentage of those infected. As time has passed, other symptoms have been recognized. The initial reports of cutaneous manifestations were from Italian dermatologists, probably because Italy was the first European country to be heavily affected by the pandemic. The overall clinical presentation, course and outcome of SARS-CoV-2 infection in children differ from those in adults as do the cutaneous manifestations of childhood. In this review, we summarize the current knowledge on the cutaneous manifestations of COVID-19 in children after thorough and critical review of articles published in the literature and from the personal experience of a large panel of paediatric dermatologists in Europe. In Part 1, we discuss one of the first and most widespread cutaneous manifestation of COVID-19, chilblain-like lesions. In Part 2, we review other manifestations, including erythema multiforme, urticaria and Kawasaki disease-like inflammatory multisystemic syndrome, while in Part 3, we discuss the histological findings of COVID-19 manifestations, and the testing and management of infected children, for both COVID-19 and any other pre-existing conditions.

Chilblain-like lesions (COVID-19 toes) have the same impact on family members than psoriasis systemically treated: insights from a case-control study targeting the pediatric population.

OBJECTIVE: COVID-19 toes represent the main dermatological COVID-19 cutaneous manifestation in pediatric patients. Its diagnosis exposes the whole family to social stigma and this aspect was not previously evaluated. PATIENTS AND METHODS: This was a multicenter, case-control, observational study that compared the family impact of COVID-19 toes vs. psoriasis (PsO). We enrolled 46 pediatric patients (23 with psoriasis and 23 with COVID-19 toes, age and gender matched) and their parents/caregivers that had to fill the Dermatitis Family Impact (DFI) questionnaire. RESULTS: DFI index did not differ significantly between both subgroups (p=0.48), and in psoriatic patients did not correlate with both Psoriasis Area Severity Index (PASI) (p=0.59) and itch-VAS (p=0.16). CONCLUSIONS: COVID-19 toes, a transitory dermatosis, exerted a similar impact/perturbation on family dynamics than PsO, a well-known stigmatizing, chronic inflammatory dermatosis.

The CTG repeat expansion size correlates with the splicing defects observed in muscles from myotonic dystrophy type 1 patients.

BACKGROUND: Myotonic dystrophy type 1 is caused by an unstable (CTG)n repetition located in the 3'UTR of the DM protein kinase gene (DMPK). Untranslated expanded DMPK transcripts are retained in ribonuclear foci which sequester CUG-binding proteins essential for the maturation of pre-mRNAs. AIM: To investigate the effects of CTG expansion length on three molecular parameters associated with the DM1 muscle pathology: (1) the expression level of the DMPK gene; (2) the degree of splicing misregulation; and (3) the number of ribonuclear foci. METHODS: Splicing analysis of the IR, MBNL1, c-TNT and CLCN1 genes, RNA-FISH experiments and determination of the DMPK expression on muscle samples from DM1 patients with an expansion below 500 repetitions (n = 6), DM1 patients carrying a mutation above 1000 CTGs (n = 6), and from controls (n = 6). RESULTS: The level of aberrant splicing of the IR, MBNL1, c-TNT and CLCN1 genes is different between the two groups of DM1 muscle samples and correlates with the CTG repeat length. RNA-FISH analysis revealed that the number of ribonuclear foci in DM1 muscle sections increases in patients with a higher (CTG)n number. No relationships were found between the expression level of the DMPK gene transcript and average expansion sizes. CONCLUSION: The CTG repeat length plays a key role in the extent of splicing misregulation and foci formation, thus providing a useful link between the genotype and the molecular cellular phenotype in DM1.

Italian guidelines for molecular analysis in myotonic dystrophies.

Myotonic dystrophies, the most common form of adult muscular dystrophy, comprise at least two forms, clinically and genetically heterogeneous. Myotonic dystrophy type 1 and type 2 are both caused by unstable repetitions in untranslated gene regions: a [CTG]n expansion in the 3' region of the DMPK gene on chromosome 19q13 (DM1) and [CCTG]n tetranucleotide repeat located in the first intron of the ZNF9 gene on chromosome 3q21 (DM2). DM clinical features are caused by a gain of functions RNA mechanism in which the CUG and CCUG repeats alter nuclear functions, including alternative splicing of shared genes. Southern blot and/or polymerase chain reaction PCR-based approaches allow the detection of DM mutations in almost 100% of cases, however, the expansion size and the elevated grade of somatic instability make molecular testing for DM a diagnostic challenge. The increased use of DNA testing for DM generates many questions regarding the indications and interpretations of the test which require standardized methods, routinely available in molecular genetic laboratories. Here, we propose Guidelines for the molecular diagnosis of DM1 and DM2 approved by the Italian Ministry of Health in 2005 (Piano Nazionale Linee Guida, PNLG). Best practice for DM molecular analysis in diagnostic application, presymptomatic and prenatal testing, using direct and indirect approaches are described, with particular attention focused on ethical, legal and social issues. Overviews of materials used in the molecular diagnosis, as well as internet resources, are also included.

Progression of mycosis fungoides is associated with changes in angiogenesis and expression of the matrix metalloproteinases 2 and 9.

Changes in angiogenesis and expression of extracellular matrix-degrading enzymes have been substantiated during progression of solid tumours, whereas information on haematological tumours remains circumstantial. In this study, 57 biopsies of mycosis fungoides (MF), a haematological tumour of T-cell lineage, were investigated immunohistochemically for the extent of angiogenesis, and by in situ hybridisation for the expression of matrix metalloproteinases 2 (MMP-2, collagenase A) and 9 (MMP-9, collagenase B). The biopsies we grouped according to the stage of progression: patch-->plaque-->nodular (most advanced). The extent of angiogenesis, as microvessel area, of MF lesions as a whole was significantly higher than that of normal uninjured skin, used as a control. When the stages of MF progression were compared, the values of MF patch stage overlapped that of control skin, while values were significantly higher in the plaque stage and even higher in the nodular stage. In these stages, microvessels were widely scattered in the tumour tissue, in close association with tumour cells, and they frequently displayed arborisation and microaneurysmatic dilation. In contrast, in the patch stage microvessels were irregularly distributed around the tumour aggregates, and arborisation or dilated structures were only rarely seen. The expression of MMP-2 and MMP-9 mRNAs underwent significant upregulation in relation to advancing stage. Indeed, the upstaging was significantly associated with higher proportions of lesions positive for each mRNA or for both, and with lesions with the greatest intensity of expression for each mRNA. Besides tumour cells, the MMP-2 mRNA was expressed by microvascular endothelial cells of intratumour and peri-tumour vessels, and by fibroblasts which were especially abundant in the stroma adjacent to the tumour nodules. The MMP-9 mRNA was found to be present in a subset of tissue macrophages which were more frequently located in close vicinity to the tumour nodules. In contrast, in control skin, a weak positivity for the MMP-2 mRNA in very few microvascular endothelial cells and no signal for the MMP-9 mRNA were observed. These in situ data suggest that angiogenesis and degradation of the extracellular matrix occur simultaneously during MF progression. They imply that interaction between tumour cells and their microvasculature are all the more likely to occur during progression, occasionally with the contribution of tumour-associated stromal cells.

Congenital self-healing histiocytosis.

In a typical case of congenital self-healing histiocytosis of the Hashimoto-Pritzker type, the results of an ultrastructural examination of a nodule of a 30-day-old patient showed that about 25% of the cells contained unique phagosomes but no regularly laminated bodies. This case of congenital self-healing histiocytosis is an example of concurrent proliferation of two types of histiocytes (one with and one without Langerhans' granules). Since transitional forms were not observed, this finding might indicate the existence of congenital, self-healing forms of histiocytosis X.

Factors influencing the localization of atopic dermatitis.

Atopic dermatitis is clinically characterized by the involvement of preferential sites. Some of these localizations, such as the face in the first year of life and later on the flexural aspect of the limbs, are constant and thus characteristic of atopic dermatitis. They are probably determined by factors that are identical for all subjects, whereas the less constant localizations are probably influenced by individual factors. The author discusses from a clinical point of view the factors that can influence localization and the lack of involvement of certain sites in atopic dermatitis. An unusual localization of atopic dermatitis, such as around congenital nevi, is also discussed.

Atopic dermatitis in the first six months of life.

1,476/2,320 of our cases of atopic dermatitis (AD) start in the first six months of life. The diagnosis is usually easy, but at this age it is sometimes more difficult, mainly because of lack of or rare evidence of scratching, but also because of the brief clinical history that does not allow observation of the characteristic chronic and relapsing course. Moreover, the major atopic disorders-asthma, rhinitis-usually appears later in the natural history of atopic subjects. From a differential diagnosis point of view, AD is the most definite dermatological disorder at this age. Other not well defined conditions occurring in the first six months of life are usually referred to as infantile seborrheic dermatitis, a name that has been used for at least four different disorders: cradle cap, cradle cap with involvement of inguinal, axillary and retroauricular folds, napkin psoriasis and Leiner's erythroderma. From a clinical point of view, AD in the first months of life is characterized by the prevalence of exudating lesions; moreover, the lack of or the rare evidence of scratching allows us to observe isolated vesicular lesions that are found with difficulty in the further course of the disease.

Correlation between clinical and immunological findings in atopic dermatitis.

Many immunological alterations have been reported in atopic dermatitis, and it is likely that in some cases they are capable of worsening the clinical course of atopic dermatitis (AD). More frequently these alterations are responsible for conditions associated with AD such as asthma, food allergy and infections. It seems probable that in some cases they are evidence of a preclinical allergic manifestation. However, in most cases, it is likely that the immunological alterations do not affect significantly the clinical course of the disease.

Role of some infectious agents in atopic dermatitis.

Certain infections such as Kaposi's herpetic eruption, impetigo, recurrent cutaneous herpes simplex and warts are more frequent in subjects with atopic dermatitis. It is likely that the continuous alterations of the skin are more important than immunological factors in increasing the frequency of some infections in subjects with atopic dermatitis. Moreover, these infections do not seem to affect significantly the clinical course of atopic dermatitis.

[Epidermal hamartoma and blaschkitis in an adult]. / Hamartome épidermique et blaschkite de l'adulte homolinéaires.

INTRODUCTION: Many inherited skin diseases and nevus malformations are distributed according to the Blaschko's lines. Some inflammatory skin diseases are also distributed according to these lines. OBSERVATION: In 1989 a 49-year-old woman presented with an epidermal nevus affecting the left hand and leg from the infancy. In 1994, inflammatory, linear papules occurred on the left leg, obscuring and continuing the previous lesions, on the left thigh and on the left clavicular region. On light microscopy, spongiosis of the epidermis and an infiltrate of lymphocytes and histiocytes in the superficial dermis were shown. Subintrant crops of new inflammatory lesions occurred for a period of two years, whereas the nevus lesions of the left hand persisted unchanged. These findings led to the final diagnosis of blaschkitis associated to epidermal nevus on the same Blaschko's lines. DISCUSSION: The distribution of a skin disease according to the Blaschko's lines underlines the presence in the affected skin of a mutant clone, with a different genetic material as compared with the normal skin. An early mutation giving raise to a mutant clone and affecting the left hemibody could be hypothesized in our case. The mutation probably involved a pleiotropic gene. The latter initially was responsible for thickening of the skin. Moreover, the mutation was also responsible for a particular proneness towards an exogenous factors, able to induce a persistent inflammatory skin eruption following the same lines.

Brain involvement in myotonic dystrophies: neuroimaging and neuropsychological comparative study in DM1 and DM2.

The objective of this study was to determine the degree of brain involvement in a cohort of myotonic dystrophy type 1 and type 2 (DM1, DM2) patients by brain studies and functional tests and to compare the results of the two groups. DM1, DM2 are multisystemic disorders due to polynucleotide expansions. Previous studies on brain involvement by neuroimaging and functional methods have led to contradictory results. Fifty molecularly defined DM1 patients and 14 DM2 patients, were recruited for the study. Age at recruitment, age at disease onset, disease duration and educational level were recorded. Neuromuscular assessment was done by MIRS. An extensive neuropsychological battery was performed in 48/50 DM1 and in a control group of 44 healthy matched subjects. Forty six of 50 DM1 and 12/14 DM2 underwent brain MRI; 21/50 DM1 and 9/14 DM2 underwent brain perfusion SPECT, with semiquantitative analysis of the results. MRI images were classified by ARWMC (age-related white matter changes) score, in order to quantify recurrence, localization and patterns of distribution of white matter hyperintense lesions (WMHLs) in our two cohorts. MRI results were matched to SPECT and to neuropsychological results. Thirty-seven of 46 DM1 and 10/12 DM2 had abnormal MRI imaging, showing scattered supratentorial, bilateral, symmetrical focal or diffuse WMHLs. A typical temporo-insular diffuse subcortical pattern was seen in DM1 subjects only, with no correlation with cognitive involvement. Major cognitive involvement was seen in the case of diffuse frontal lesions. A relationship with CTG expansion size was documented for DM1 subjects. SPECT showed minimal hypoperfusion in the posterior cortex planes in DM1 and, to a lesser extent, in DM2. Very mild degrees of involvement in the DM2 cohort were seen. Neuroimaging and functional investigations confirmed a more severe involvement of the brain in DM1 compared to DM2. A temporo-insular diffuse lesional pattern, specific for DM1, was found on MRI. This confirms greater expansion size as a risk factor for more extensive brain involvement in DM1.