[Importance of biopsy in the diagnostic assessment of chronic wounds-position paper of the Initiative Chronische Wunden (ICW) e. V.]

Diagnostic assessment of chronic wounds is essential for the initiation of causal therapeutic treatment. For diagnostic classification of the wound genesis, it may be necessary to take a tissue sample for histological and/or microbiological processing. If there is clinical suspicion of a specific cause of the wound such as a neoplasm, an inflammatory dermatosis or a pathogen-induced wound, a tissue sample for further diagnosis is required immediately. If the ulceration does not respond sufficiently to adequate causal therapy, a tissue sample for further evaluation is recommended after 12 weeks. The choice of the correct sampling technique, further storage, transport and processing are just as decisive for a reliable result as the specific question for the diagnostic laboratory.

[The term mixed leg ulcer should no longer be used today]

A wound on the lower legs of patients with chronic venous insufficiency (CVI) and peripheral arterial disease (PAD) is today usually referred to as a mixed leg ulcer. This does not take into account the different stages of the diseases and, thus, their pathophysiological relevance. In everyday clinical practice, this often leads, among other things, to these patients not receiving compression therapy. The multidisciplinary professional association Initiative Chronische Wunden (ICW) e. V., therefore, recommends that this undifferentiated and misleading term should no longer be used. Instead, a leg ulcer with advanced CVI and concomitant PAD in stage I-IIb according to Fontaine or Rutherford category 0-3 should be classified as a venous leg ulcer, while a leg ulcer with advanced PAD in stage III or IV according to Fontaine or Rutherford category 4-6 and advanced CVI is termed an arteriovenous leg ulcer. A leg ulcer in advanced PAD stage IV according to Fontaine or Rutherford category 5 or 6 without advanced CVI is called an arterial leg ulcer. Other relevant comorbidities with an influence on wound healing should also be described separately.

Was hat die Ernährung mit der Wundheilung zu tun?

Bei einer Störung im Ablauf der Wundheilung kann es zu einem verzögerten oder fehlenden Wundverschluss kommen. Als ein möglicher Störfaktor gilt die Ernährung. Man muss zwischen quantitativer und qualitativer Mangelernährung unterscheiden. Gerade übergewichtige Patienten leiden oft an einer qualitativen Mangelernährung und Sarkopenie.

Spezifische Erkrankungen machen eine entsprechende diätetische Nahrungsempfehlung notwendig. So findet man bei dialysepflichtigen Patienten, Dekubitus-Patienten und Ulcus cruris-Patienten oft einen Eiweißmangel. Auch niedrige Level an Vitamin C, Zink, Folsäure, Vitamin D oder Spurenelementen können die Wundheilung negativ beeinflussen.

Größere prospektive Studien sollten klären, ob eine Substitution dieser Mangelzustände den gewünschten positiven Effekt auf die Wundheilung hat. Es erscheint aber sinnvoll, eine ausgewogene Ernährung und an die individuellen Ernährungsgewohnheiten angepasste Verbesserung der Aufnahme von Vitaminen, Spurenelementen und Eiweißen anzustreben.

Necrobiosis lipoidica – Klinische Charakteristika und therapeutische Ansätze

Die Necrobiosis lipoidica ist eine seltene granulomatöse Dermatose, die sich vornehmlich an den Streckseiten der unteren Extremitäten mit gelblich-bräunlichen Plaques manifestiert. Ulzerationen können den Verlauf erschweren. Klare Therapieempfehlungen fehlen, da aufgrund der geringen Patientenzahlen keine großen randomisierten Studien vorliegen. Neben dem Einsatz von Glukokortikoiden scheinen Fumarsäureester und Biologika therapeutisch vielversprechend.

Verrucous carcinoma in epidermolysis bullosa simplex is possibly associated with a novel mutation in the keratin 5 gene

Epidermolysis bullosa simplex (EBS) is mainly caused by mutations in the KRT5 and KRT14 genes. Squamous cell carcinoma (SCC) represents the second most frequent skin neoplasia with complex aetiology. The molecular events disrupting the orchestrated interplay between the cytoskeleton, cell adhesion molecules and signalling proteins are ill understood in SCC. We describe the molecular background and the unusual course of the disease in a patient with EBS Dowling-Meara, severe keratoderma and a massive verrucous carcinoma. Skin and tumour samples from the patient were analysed using light microscopy, immunohistochemistry and immunofluorescence mapping. Mutation analysis of the KRT5 and KRT14 genes identified the novel KRT5 mutation p.E477D. Invasive tumour areas were characterized by downregulation of keratins 5 and 14, reduced and irregular desmocollin-2 expression and increased expression of keratins 6, 16 and 17. Levels of Ki-67 were increased and levels of E-cadherin strongly reduced in the tumour tissue. In this case a novel KRT5 mutation led to increased fragility of keratinocytes. Desmosome and adherens junctions were destabilized, which may trigger keratinocyte-mediated inflammation, possibly via p120-catenin-dependent signalling, suggesting a link between a keratin mutation and SCC, which adds weight to the hypothesis that disturbance of the cytoskeleton represents a major cause in the appearance of the malignant phenotype. Some individuals with EBS may be at risk of developing secondary SCC.