Ketogenic Diet and the Skin

In dermatology, the role of dietary modifications as a means to manage or prevent skin disorders has recently gained special attention among patients and physicians. This is especially true for the currently popular ketogenic diet (KD), which comprises low carbohydrate, high fat, and adequate amount of protein. Recent evidence from basic science research, small clinical trials, population studies, and reports has presented promising potential role of KD as a supplementary or adjuvant treatment in different cutaneous disorders mainly due to its anti-inflammatory properties. This review is directed at raising awareness among dermatologists on the potential uses of KD in managing skin disorders, such as acne, psoriasis, and hidradenitis suppurativa, among others. In addition, cutaneous adverse reactions, such as prurigo pigmentosa and nutritional deficiencies, which have been associated with KD, are also discussed in this review.

Correlation between Thyroid Radiation Dose and Thyroid Function after Adjuvant Hypofractionated Locoregional Radiotherapy in Breast Cancer Patients

PURPOSE/OBJECTIVE(S)

Radiotherapy (RT) is used quite often among breast cancer patients, and because these patients now live longer than they used to, long-term treatment-related adverse effects, such as hypothyroidism, are becoming increasingly relevant. Radiation-induced hypothyroidism is a late side effect of radiation to the thyroid gland, which could develop months to years after radiotherapy. However, there is no sufficient data on hypothyroidism in patients with breast cancer who receive locoregional RT, which usually affects a portion of the thyroid gland. In this prospective study, we tried to correlate between the radiation dose received by the thyroid gland and the incidence of thyroid dysfunction in breast cancer patients treated with hypofractionated locoregional radiotherapy, as well as establishing potential planning objectives that could help in sparing the thyroid gland.

MATERIALS/METHODS

Our study included 109 women who received 3-D conformal loco-regional breast radiotherapy, these patients had normal thyroid function prior to start of radiotherapy. Patients had follow-up thyroid function tests 6 months after finishing radiotherapy. Based on dose volume histograms (DVH), the percentages of the thyroid volume, and ipsilateral thyroid lobe, receiving 5, 10, 15, 20, 25, 30, 35, and 40 Gy (V5, V10, V15, V20, V25, V30, V35, and V40 respectively), in addition to the mean and maximum thyroid doses, were estimated.

RESULTS

Follow-up assessment of thyroid function and statistical analysis unveiled incidence of radiotherapy induced hypothyroidism to be 8.3%. Possible risk factors included high maximum radiation dose and V40 to the thyroid gland and the ipsilateral thyroid lobe, as well as high mean dose and smaller volume of the ipsilateral thyroid lobe.

CONCLUSION

The likelihood of hypothyroidism was significantly increased with V40 of >5% of the thyroid gland, and V40 of >11% of the ipsilateral thyroid lobe. Further study is recommended for larger populations and longer follow-up periods.

Erosive Pustular Dermatosis of the Scalp

Erosive pustular dermatosis (EPD) is a rare entity, but it is generally overlooked or missed, rather than rarely encountered. It presents with erosions and shallow ulcers, accompanied by delayed healing and associated with cutaneous atrophy, rather than pustules. It exhibits predominance for women, with a predilection for a chronically sun-damaged scalp and, less commonly, the extremities, particularly the legs, as well as the face and mucosal surfaces. The role of infection, actinic damage, trauma, hormones, autoimmune disease, cutaneous atrophy, and genetics in the pathogenesis of EPD has been described in literature. Increased awareness and a high index of suspicion permit prompt treatment with topical corticosteroids, with or without oral zinc, followed by maintenance therapy with topical calcineurin inhibitors. Prevention, prior recognition, and prompt treatment are required for addressing this complex condition. (SKINmed. 2023;21:12-19).

Annular Lichenoid Dermatitis of Youth: Its Pathogenesis, Diagnosis, and Management

Annular lichenoid dermatitis of youth (ALDY) is a newly described controversial benign lichenoid inflammatory cutaneous disorder often characterized by annular patches with hypopigmented center and surrounding erythematous border. Primarily, it affects the trunk and groin of young patients. Since its first description in 2003, additional patients have been reported, leading to better characterization of the entity; nevertheless, the pathogenesis is still unclear, and several hypotheses have been provided about possible triggering or causative factors. It tends to follow a chronic course, with some lesions spontaneously remitting, while others may be persistent or recur post-treatment. No standard validated treatment has been indicated so far for this disorder. Commonly prescribed topical treatment includes corticosteroids and calcineurin inhibitors with variable response.

Treatments for Non-Syndromic Inherited Ichthyosis, Including Emergent Pathogenesis-Related Therapy

The term 'inherited ichthyosis' refers to a heterogeneous group of mendelian disorders of cornification that involve the integument with varying degrees of scaling. The management of ichthyosis poses a challenge for most physicians. Treatment options proposed in the literature include moisturizers, topical keratolytics, topical and systemic vitamin D analogues, and topical and systemic retinoids; however, some of these modalities are less reliable than others. Despite the therapeutic impasse imposed by the options above, the emergence of pathogenesis-based treatments along with novel gene therapies appear promising and hold the potential to halt or even revert disorders that arise from single genetic mutations, although research is still quite lacking in this domain. Hence, this review aims to highlight the various treatment modalities available for the management of the cutaneous manifestations of non-syndromic inherited ichthyosis, with an added emphasis on pathogenesis-targeted therapies.

Eosinophilic ulcer of the oral mucosa: An update on clinicopathologic features, pathogenesis, and management

Eosinophilic ulcer of the oral mucosa is a benign, reactive, self-limited lesion. Its pathogenesis is unclear, and it clinically manifests as a punched-out ulcer with surrounding indurated border, raising suspicion for a possible malignancy. On histology, an acute and chronic dense inflammatory infiltrate can be appreciated, which can extend to the deep underlying tissue (including skeletal muscle). Eosinophils are especially conspicuous on hematoxylin and eosin staining and might play an important role in the development of the ulcer. Removal of possible triggers followed by monitoring and possible biopsy are among the initial recommendations. Most lesions heal spontaneously without the need for intervention. This review aims at assisting dermatologists to easily recognize this entity, avoiding unnecessary interventions and apprehension.

Characterizing the presence of neutrophil extracellular traps in neutrophilic dermatoses

Neutrophil extracellular traps (NETs) are implicated in the pathogenesis of multiple inflammatory dermatoses. However, characterization of NETs in neutrophilic dermatoses was performed on very limited number of patients; this limitation precluded definitive conclusions. In this case series of 57 patients, we compared the amounts of neutrophils producing NETs in cutaneous lesions of different entities of neutrophilic dermatoses (17 with pyoderma gangrenosum, 37 with Sweet's syndrome and three with subcorneal pustular dermatosis). NETs were identified by double immunofluorescence on formalin-fixed paraffin-embedded skin biopsies using antibodies against elastase and citrullinated histone 3. Percentages of neutrophils showing NETs were high across all three entities (62.9% in PG, 48.5% in SS and 37.8% in subcorneal pustular dermatosis). The differences in mean percentages were significant between entities, with PG showing significantly superior percentage of NETs compared with SS. In our series, 15.8% of neutrophilic dermatoses were associated with malignancies, 10.5% with autoimmune diseases and 73.7% were idiopathic. Percentages of NETs were not statistically different between aetiologies. These findings suggest that NETs are abundantly produced in the various entities and different aetiologies of neutrophilic dermatoses. In comparison with SS, the superior percentage of NETs in PG is clinically mirrored in its greater ulceronecrotic nature.

Genodermatoses with hearing impairment

Hearing loss is a prominent feature in multiple genodermatoses. Underappreciation of auditory deficits can misdirect proper diagnosis by the treating dermatologist. This review reviews the anatomic, developmental, and embryologic aspects that characterize the ear and summarizes genodermatoses that have aberrant auditory findings. The latter are classified into neural crest, metabolic, pigmentary, craniofacial, and a miscellaneous category of disorders lacking specific cutaneous findings. The algorithms provided in this review enable treating dermatologists to better recognize and manage genodermatoses with ear involvement.

Genodermatoses with behavioural sequelae

Children with genodermatoses are at an increased risk of developing behavioural disorders which may impart lasting damage on the individual and their family members. As such, early recognition of childhood mental health disorders via meticulous history taking, thorough physical examination, and disorder-specific testing is of paramount importance for timely and effective intervention. If carried out properly, prompt psychiatric screening and intervention can effectively mitigate, prevent or even reverse, the psychiatric sequela in question. To that end, this review aims to inform the concerned physician of the manifestations and treatment strategies relevant to the psychological sequelae of genodermatoses.

Imatinib-induced eruptive nevi

Imatinib mesylate is a tyrosine kinase inhibitor used in the treatment of a variety of oncological conditions. It has been associated with a spectrum of pigmentary cutaneous side effects. Despite the well-known association of eruptive melanocytic nevi with the use of other tyrosine kinase inhibitors, this phenomenon has not been linked to the administration of imatinib. We present the first case of imatinib-induced eruptive nevi in an 18-year-old patient with acute lymphocytic leukaemia in remission.

Osteoclast-Like Giant Cells: Focus on Entities Relevant to Dermatopathology and Underlying Pathogenesis

ABSTRACT

Osteoclast-like giant cells (OLGCs) resemble osteoclasts with their abundant cytoplasm and well-developed organelles. OLGCs are characteristic features of giant cell tumor of the tendon sheath and giant cell tumor of soft tissue but they have also been described in numerous other cutaneous conditions. The diagnostic and prognostic significance of the presence of OLGCs is unknown. Here, we summarize the clinical entities that can exhibit these cells to avoid a histological overlap, affecting diagnosis and management.

Investigating the presence of neutrophil extracellular traps in septal and lobular cutaneous panniculitides

BACKGROUND

Panniculitides are a heterogeneous group of inflammatory dermatoses involving the subcutaneous fatty tissue. Histologically, they are classified into septal and lobular panniculitis, according to the predominant localization of the inflammatory infiltrate. Neutrophils are frequently found in panniculitis, mainly at the early stages. Here, we investigated whether neutrophils contribute to various types of cutaneous panniculitis by releasing neutrophil extracellular traps (NETs).

MATERIALS AND METHODS

Formalin-fixed paraffin-embedded skin biopsies from 25 patients with panniculitis were included in the study. Our cohort was divided into n = 10 erythema nodosum (septal panniculitis) and n = 15 lobular panniculitis, including n = 7 lupus panniculitis, n = 1 pancreatic panniculitis, n = 1 Weber-Christian disease, n = 1 deep fungal infection, n = 2 lipodermatosclerosis, and three cases did not have an identified etiology. The presence of neutrophils and NETs was assessed by double immunofluorescence using antibodies against elastase, a neutrophilic marker, and citrullinated histone 3, a marker of NETs.

RESULTS

The mean percentages (±SEM) of elastase-positive neutrophils showing NETs were 44% ± 3% in erythema nodosum and 43% ± 7% in lobular panniculitis. The difference was not statistically significant and reflects the implication of NETs not only in severe scarring lobular panniculitis but also in benign non-scarring self-remitting reactive inflammation such as erythema nodosum. In tissues, NETs were located in the interlobular septa in erythema nodosum and in the inflamed fat lobules in lobular panniculitis.

CONCLUSIONS

NETs are massively present in septal and lobular subtypes of panniculitides, suggesting their involvement in tissue damage.

Diagnostic utility of plasmacytoid dendritic cells in dermatopathology

Differentiating cutaneous diseases that mimic each other clinically and histopathologically can at times be a challenging task for the dermatopathologist. At the same time, differentiation of entities with overlapping features may be crucial for patient management. Although not seen in normal skin, plasmacytoid dendritic cells usually infiltrate the skin in several infectious, inflammatory/autoimmune and neoplastic entities. Plasmacytoid dendritic cells can be identified in tissue using specific markers such as CD123 and/or blood-derived dendritic cell antigen-2. Plasmacytoid dendritic cells are the most potent producers of type I interferons and their activity may therefore be assessed indirectly in tissue using human myxovirus resistance protein A, a surrogate marker for type I interferon production. In recent years, accumulating evidence has established the utility of evaluating for specific plasmacytoid dendritic cell-related parameters (plasmacytoid dendritic cell content, distribution and clustering and/ or human myxovirus resistance protein A expression) as a diagnostic tool in differentiating cutaneous diseases with overlapping features such as the alopecias, lupus and its mimics, and neoplastic entities. In this review, we provide an update on the current evidence on this topic and on the contexts where this can be a useful adjunct to reach the histopathological diagnosis.

Dowling-Degos disease: a review

Dowling-Degos disease is a rare autosomal dominant genodermatosis. It is characterized by acquired reticulate hyperpigmentation over the flexures, comedone-like follicular papules, and pitted perioral scars that usually develop during adulthood. Mutations in genes affecting melanosome transfer, and melanocyte and keratinocyte differentiation have been implicated in the pathogenesis of this disease. These genes include KRT5, POFUT1, POGLUT1 and, most recently, PSENEN. Dowling-Degos disease can be found in isolation or with other associated findings, most notably hidradenitis suppurativa. This condition belongs to a spectrum of conditions that all result in reticulate hyperpigmentation that at times are hard to distinguish from each other. The most closely linked entity is Galli-Galli, which is clinically indistinguishable from Dowling-Degos disease and can only be distinguished by the presence of acantholysis on microscopy. Unfortunately, Dowling-Degos disease is generally progressive and recalcitrant to treatment.

Comparative characterization of sun exposed and sun protected skin-derived mesenchymal-like stem cells in variegate porphyria and healthy individuals

BACKGROUND AND PURPOSE

We hypothesized that upon sun exposure, a sub-population of primary skin-derived mesenchymal-like cells is deleteriously affected and thus contribute to the chronic inflammatory state in autosomal recessive variegate porphyria patients. The aim of this study was to isolate and characterize the mesenchymal-like stem cells from different areas of the skin in a porphyria patient (sun exposed, SE, and sun protected, SP) and to compare them with cells from a healthy individual.

METHODS

The proliferation rate and the migration ability of SE and SP cells were evaluated in the presence of an antioxidant compound, N-acetylcysteine. A co-culture of SE-damaged cells with the conditioned medium from the enriched mesenchymal cell-like SP population was performed in order to regenerate the dermal injured tissue after sun exposure in patients.

RESULTS

Results showed that the percentage of CD105⁺ cells varies between 3.9% in SP and 5% in SE of the healthy individual and between 3.6% and 1.4% in SP and SE in the porphyria patient, respectively. The osteogenic differentiation potential was lower in the porphyria patient when compared to the control. Furthermore, the expression of stem cell markers was more pronounced in SE than in SP cells of both control and porphyria. The use of N-acetyl cysteine did not show any beneficial effects on porphyria SE cells. Treatment with SP-conditioned medium slightly increased the expression of stem cell markers in SE of porphyria patient.

CONCLUSION

In conclusion, the pool of mesenchymal stem-like SE cells is affected in variegate porphyria patient along with modification of their self-renewal and differentiation properties.

Integrative Transcriptome Analyses Empower the Anti-COVID-19 Drug Arsenal

The beginning of the 21st century has been marked by three distinct waves of zoonotic coronavirus outbreaks into the human population. The COVID-19 (coronavirus disease 2019) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and emerged as a global threat endangering the livelihoods of millions worldwide. Currently, and despite collaborative efforts, diverse therapeutic strategies from ongoing clinical trials are still debated. To address the need for such an immediate call of action, we leveraged the largest dataset of drug-induced transcriptomic perturbations, public SARS-CoV-2 transcriptomic datasets, and expression profiles from normal lung transcriptomes. Most importantly, our unbiased systems biology approach prioritized more than 50 repurposable drug candidates (e.g., corticosteroids, Janus kinase and Bruton kinase inhibitors). Further clinical investigation of these FDA-approved candidates as monotherapy or in combination with an antiviral regimen (e.g., remdesivir) could lead to promising outcomes in patients with COVID-19.

Neutrophil Extracellular Traps are Present in Immune-complex-mediated Cutaneous Small Vessel Vasculitis and Correlate with the Production of Reactive Oxygen Species and the Severity of Vessel Damage

Formation of neutrophil extracellular traps has been implicated in autoimmunity. However, the presence and clinical relevance of neutrophil extracellular traps in immune-complex-mediated cutaneous small and medium vessel vasculitides has not been investigated. This study retrospectively analysed 72 patients with histology-proven hypersensitivity vasculitis (n = 21), IgA vasculitis (n = 22), urticarial vasculitis (n = 22), erythema elevatum diutinum (n = 3) and polyarteritis nodosa (n = 4). Neutrophil extracellular traps were detected in hypersensitivity vasculitis, IgA vasculitis, urticarial vasculitis and erythema elevatum diutinum, but not in polyarteritis nodosa lesions. Neutrophil extracellular traps were found around inflamed vessels, and their formation was highest early after the onset of vasculitis and decreased progressively thereafter. Neutrophil extracellular traps were strongly correlated with the histological severity of vasculitis and the production of reactive oxygen species. Both hypersensitivity vasculitis and IgA vasculitis showed significantly more neutrophil extracellular traps than did urticarial vasculitis, independent of the histological severity and duration of vasculitis. These results provide evidence on the implication of neutrophil extracellular traps in the early phases of immune-complex-mediated small vessel vasculitis.

Follicular mucinosis: a review

Follicular mucinosis (FM) is an epithelial reaction pattern characterized by follicular mucin accumulation. It has been described in association with various inflammatory and neoplastic cutaneous disorders. FM is generally divided into a primary benign idiopathic form and a secondary form usually occurring in association with cutaneous lymphomas (especially mycosis fungoides), among other entities. Distinction between the two forms can be challenging as they share many overlapping features and the lack of a single diagnostic tool to differentiate between the two. Making the distinction may require evaluating and correlating the clinical, histologic, immunohistochemical, and molecular studies together. Long-term clinical follow-up also remains very important. In this review, we describe the different entities associated with FM, its pathogenesis, and possible therapeutic options.

A novel TRAF3IP2 variant causing familial scarring alopecia with mixed features of discoid lupus erythematosus and folliculitis decalvans

Discoid lupus erythematosus (DLE) is an autoimmune disorder with a poorly defined etiology. Despite epidemiologic gender and ethnic biases, a clear genetic basis for DLE remains elusive. In this study, we used exome and RNA sequencing technologies to characterize a consanguineous Lebanese family with four affected individuals who presented with classical scalp DLE and generalized folliculitis. Our results unraveled a novel biallelic variant c.1313C > A leading to a missense substitution p.(Thr438Asn) in TRAF3IP2(NM_147200.3). Expression studies in cultured cells revealed mis-localization of the mutated protein. Functional characterization of the mutated protein showed significant reduction in the physical interaction with the interleukin 17-A receptor (IL17RA), while interaction with TRAF6 was unaffected. By conducting a differential genome-wide transcriptomics analysis between affected and non-affected individuals, we showed that the hair follicle differentiation pathway is drastically suppressed, whereas cytokine and inflammation responses are significantly upregulated. Furthermore, our results were highly concordant with molecular signatures in patients with DLE from a public dataset. In conclusion, this is the first report on a new putative role for TRAF3IP2 in the etiology of DLE. The identified molecular features associated with this gene could pave the way for better DLE-targeted treatment.

SuPAR, a potential inflammatory mediator in psoriasis pathogenesis

Psoriasis is an inflammatory skin disorder that is strongly associated with the metabolic syndrome. The sole reliance on clinical examination to guide prognostication and treatment is insufficient at best; accurate diagnostic and prognostic psoriatic molecular biomarkers are needed. Soluble urokinase plasminogen activator receptor (suPAR) has been implicated in inflammation. The aim of this study is to determine whether suPAR plays a role in the pathogenesis of psoriasis and whether an association exists between suPAR levels, disease severity, and other variables like insulin, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). This study also compares the pattern of uPAR staining in healthy vs psoriatic skin: 39 psoriatic and 30 control subjects were included. Two biopsies (affected and unaffected skin) and one biopsy were taken from psoriasis patients and healthy controls, respectively, with uPAR staining of all skin biopsies. Blood samples from all subjects were obtained to determine suPAR, ESR, CRP, and fasting insulin levels. uPAR staining was prominent in unaffected skin from psoriasis patients and healthy individuals vs weak/absent uPAR staining in psoriatic skin. CRP, ESR and suPAR levels were not significantly elevated in the mild psoriasis group compared to healthy controls. The loss of epidermal uPAR is suggestive of its tentative role in the pathogenesis of psoriasis. Patients with mild-moderate psoriasis possibly lack the powerful association attributed to metabolic syndrome in psoriatic patients. Further studies on larger cohorts are needed to ascertain the validity of the mentioned conclusions.

Ustekinumab Successfully Treats and Maintains Remission of Pyostomatitis Vegetans Associated with Crohn's Disease

Pyostomatitis vegetans (PV) is a rare inflammatory stomatitis often associated with inflammatory bowel diseases (IBD). Treatment of PV depends on the presence of coexisting IBD. To date, there have been no reports on the use of ustekinumab for PV. There have been recent cases on the use of ustekinumab for treatment of pyoderma gangrenosum and uveitis. We report the case of a 26-year-old female with moderately severe Crohn's disease (CD) and PV who was successfully treated with ustekinumab monotherapy. Since initiation of ustekinumab, she has been in clinical and biochemical remission from a CD and PV standpoint for the last 12 months.