Skin signs in diabetes mellitus

Diabetes mellitus is the most common endocrine disorder with continuously increasing prevalence. Blood vessels, nerves, eyes, kidneys and skin are affected, which causes both an enormous financial burden and a reduced quality of life of the affected patients. Long-standing diabetes may impair skin homeostasis resulting in skin manifestations in at least one third of all diabetics. The skin involvement may be the first presenting sign of diabetes, thus the respective skin signs should lead to diabetes focused diagnostic. Besides, the skin signs may be considered as a marker for the course of the disease or for the success of therapeutic interventions.

Activation of the PI3K/AKT pathway in Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with an increasing incidence. The understanding of the molecular carcinogenesis of MCC is limited. Here, we scrutinized the PI3K/AKT pathway, one of the major pathways activated in human cancer, in MCC. Immunohistochemical analysis of 41 tumor tissues and 9 MCC cell lines revealed high levels of AKT phosphorylation at threonine 308 in 88% of samples. Notably, the AKT phosphorylation was not correlated with the presence or absence of the Merkel cell polyoma virus (MCV). Accordingly, knock-down of the large and small T antigen by shRNA in MCV positive MCC cells did not affect phosphorylation of AKT. We also analyzed 46 MCC samples for activating PIK3CA and AKT1 mutations. Oncogenic PIK3CA mutations were found in 2/46 (4%) MCCs whereas mutations in exon 4 of AKT1 were absent. MCC cell lines demonstrated a high sensitivity towards the PI3K inhibitor LY-294002. This finding together with our observation that the PI3K/AKT pathway is activated in the majority of human MCCs identifies PI3K/AKT as a potential new therapeutic target for MCC patients.

Cytokines, chemokines and growth factors in wound healing

In wound healing, a variety of mediators have been identified throughout the years. The mediators discussed here comprise growth factors, cytokines and chemokines. These mediators act via multiple (specific) receptors to facilitate wound closure. As research in the last years has led to many new findings, there is a need to give an overview on what is known, and on what might possibly play a role as a molecular target for future wound therapy. This review aims to keep the reader up to date with selected important and novel findings regarding growth factors, cytokines and chemokines in wound healing.

Kyrle disease and acquired perforating collagenosis secondary to chronic renal failure and diabetes mellitus

A 59-year-old man with chronic renal failure and diabetes mellitus presented with pruritic crusted lesions which histologically were perforating disorders, showing features of both Kyrle disease and acquired perforating collagenosis. The mechanisms of transepidermal elimination and the classification of perforating disorders are briefly discussed. Additionally, we question the concept of perforation, as epidermal damage and exposure of subepidermal substances may artificially present as perforation.

[Graft-versus-host disease (GvHD) - an update. Part 2: prognosis and therapy of GvHD]

Graft-versus-host disease (GvHD) remains one of the major complications after allogeneic stem cell transplantation (SCT) and is responsible for morbidity, mortality and decrease in quality of life of patients after SCT. The most important preventive approach is the selection of a donor with best possible HLA compatibility between donor and recipient. Basic prophylaxis of acute GvHD begins already prior to transplantation and usually consists of cyclosporine with or without methotrexate. In the past few years, many new therapies have been introduced for the treatment of acute and chronic GvHD. Extracorporeal photopheresis (ECP), for example, represents a promising treatment option for acute and chronic GvHD with very few side effects. For chronic GvHD mTOR inhibitors (sirolimus, everolimus) may replace calcineurin-inhibitors with the advantage of not inducing malignant skin tumors. Guidelines are available ort he management of acute and chronic GvHD. While pathophysiology, classification and skin manifestations of GvHD have been already presented in the first part of this article, this second part covers the prognosis, prevention and treatment of GvHD.

Generalized solar lentigines in a patient with a history of radon exposure

A woman with generalized lentigines without associated non-cutaneous abnormalities is described. The patient showed brownish-pigmented flat or slightly elevated spots with a diameter of 1–5 mm. The histopathology of the lesions was compatible with a diagnosis of solar lentigines (SLs) or flat seborrhoeic keratosis. Unlike SLs, which develop typically on sun-damaged skin of the face, the dorsum of the hands and forearms, this patient showed the lentigines most prominently on the thighs and lower legs. Besides increased recreational UV exposure, the patient had a history of occupational radon exposure in a spa with radon-containing water. Genetic analysis identified a p.S249C FGFR3 hotspot mutation in 1 lesion, supporting the diagnosis of SLs. It remains elusive whether the occupational exposure to radon-containing water in addition to the recreational UV light exposure caused the unusual distribution of the SLs in this patient.

Low incidence of EGFR and HRAS mutations in cutaneous squamous cell carcinomas of a German cohort

Epidermal growth factor receptor (EGFR) is highly expressed in squamous cell carcinoma (SCC). The response of patients with lung cancer to EGFR inhibitors is significantly associated with the presence of EGFR mutations. Although these drugs have already been used for the treatment of advanced cutaneous SCC, the knowledge about EGFR mutations in this cancer is limited to one previous study in the US population. We analysed the presence of EGFR and concomitant HRAS mutations in a German cohort of 31 patients with cutaneous SCC by direct sequencing of EGFR and SNaPshot analysis of concomitant RAS mutations. We found a low prevalence of EGFR mutations (1/31; 3%) and HRAS mutations (1/31; 3%). The detected P741L EGFR mutation was proven to be somatic. Our results indicate that both EGFR and HRAS mutations are rare events in the carcinogenesis of cutaneous SCC, and therefore, only a small subgroup of patients will benefit from the screening for EGFR mutations in the run-up to targeted therapies with EGFR inhibitors.

[Graft-versus-Host Disease (GvHD) - an update : Part 1: Pathophysiology, clinical features and classification of GvHD]

GvHD remains associated with significant morbidity and mortality despite new techniques for allogeneic stem cell transplantation (SCT), such as optimized conditioning regimens. Within the past ten years, the incidence of acute GvHD has remained unchanged and the incidence of chronic GvHD has even increased. The traditional classification of GvHD according to the time of clinical manifestation is now out-dated. Acute GvHD symptoms may even occur after 100 days; vice versa, primary chronic GvHD may already be observed one month after stem cell transplantation. The current classification introduced by the National Institutes of Health includes classic acute GvHD (up to 100 days), late-onset acute GvHD (after 100 days), as well as an overlap syndrome showing features of acute and chronic GvHD and classic chronic GvHD without any time limit. Diagnosis of GvHD of the skin remains difficult because of histological similarities to drug eruptions and viral exanthems. In this first part of the article the pathophysiology, classification, skin manifestations of acute and chronic GvHD and the histopathology will be presented. In a second part the prognosis, prophylaxis and therapy of GvHD will be discussed.

Skin alterations due to illegal drug abuse

Drug abuse is associated with a wide variety of skin alterations. Being aware of the typical signs and symptoms of the drug addicts' skin is of special importance to dermatologists, even though dermatologists are commonly not involved in the treatment of these patients. There is yet a chance for dermatologists to identify drug abusers early by to some extent specific cutaneous signs and after exclusion of several other etiological factors, so that this will lead to further treatment through the respective specialists. The objective of this paper is to draw particular attention to typical skin lesions and diseases which may be associated with drug abuse.