Molekulare Diagnostik von Hautinfektionen am Paraffinmaterial - Übersicht und interdisziplinärer Konsensus

Status quo and future perspectives of molecular diagnostics in dermatology

Molecular diagnostics (MDx) has become an indispensable pillar of diagnostics in dermatology. Modern sequencing technologies allow for identification of rare genodermatoses, analysis of somatic mutations in melanoma are prerequisite for targeted therapies, and cutaneous infectious pathogens are quickly detected by PCR and other amplification methods. However, to push innovation in molecular diagnostics and tackle so far unmet clinical needs, research activities need to be bundled and the pipeline from idea to MDx product clearly rolled out. Only then, the requirements for technical validity and clinical utility of novel biomarkers can be fulfilled and the long-term vision of personalized medicine will be realized.

[Parasitic dermatoses from abroad]

Increased migration, the omnipresent desire to travel, climate change and a globally more mobile population enhance the risk of spreading infectious, tropical pathogens across international borders. In addition to diarrhea and fever, skin diseases present one of the most common reasons for a medical consultation upon return among travelers. These diseases are often caused by parasites. Detailed data on infectious travel diseases is scarce. However, demographic, endemic and travel-related information represent the basic requirements for physicians to choose appropriate diagnostics and adequate treatment for affected patients. This article gives an overview of common parasitic travel dermatoses, their specific diagnostic workup, treatment and preventive measures.

[S2k guideline for the diagnosis and therapy of zoster and post-zoster neuralgia]

Diese Leitlinie richtet sich an Dermatologen, Ophthalmologen, HNO-Ärzte, Pädiater, Neurologen, Virologen sowie Infektiologen, Anästhesisten und Allgemeinmediziner in Klinik und Praxis und dient zur Information für andere medizinische Fachrichtungen, die an der Behandlung des Zoster beteiligt sind. Darüber hinaus soll die Leitlinie Kostenträgern und politischen Entscheidungsträgern zur Orientierung dienen. Die Leitlinie wurde im formellen Konsensusverfahren (S2k) von Dermatologen, Virologen/Infektiologen, Ophthalmologen, HNO-Ärzten, Neurologen, Pädiatern und Anästhesisten/Schmerzmedizinern erstellt.

Die Leitlinie stellt einen Überblick über die klinische und molekulare Diagnostik sowie den Antigennachweis, die Antikörperkultur und Viruskultur dar. Diagnostisch besondere Situationen und komplizierte Verläufe der Erkrankung finden ebenfalls Berücksichtigung. Die antivirale Therapie des Zoster und der Postzosterneuralgie wird im Allgemeinen und für besondere Situationen dargelegt. Detaillierte Angaben zur Schmerzbehandlung finden Erwähnung und sind in einer Übersicht dargestellt. Ebenso werden die lokaltherapeutischen Maßnahmen thematisiert.

[Scabies in old age]

Scabies is a frequent ectoparasitosis the prevalence of which also seems to increase in older patients. Correct and timely diagnosis of scabies in older age is hampered by atypical clinical manifestations, the potential lack of pruritus and a variety of differential diagnoses. Scabies crustosa, a highly contagious subtype due to the presence of innumerable mites, is of particular importance. It predominantly occurs in immunosuppressed patients as well as in mentally or physically disabled persons and is the most important source of scabies outbreaks in residential and nursing homes. This article reviews the diagnosis and treatment of scabies and the strategies for managing outbreaks with special reference to older patients.

[Painful lymphadenopathy after an insect bite-a case report]

Tularemia is a bacterial zoonosis which is commonly transmitted through tick or insect bites or contact with meat of infected animals. We report the case of a 36-year-old man who developed fever, chills, headaches, and a painful, unilateral, inguinal lymphadenopathy with a red-livid skin discoloration after an insect bite on his abdomen. Ulceroglandular tularemia was diagnosed through polymerase chain reaction (PCR) and serology. Treatment with doxycycline for 21 days resulted in an excellent outcome.

[Relevance of biopsies for the diagnostics of infectious skin diseases]

Pathogen-related skin infections are a common problem in the dermatological practice. Apart from culturing and serological detection methods, a skin biopsy is a possible diagnostic procedure, especially when the clinical picture is unspecific and other non-infectious skin diseases are considered as possible differential diagnoses. Some organisms can already be detected by routine staining methods (hematoxylin & eosin, e. g., yeasts, Leishmania), for others numerous histochemical and immunohistochemical stains are available, e. g. periodic acid-Schiff reaction (PAS) and Grocott for hyphae and spores, Ziehl-Neelson and Fite-Faraco for Mycobacteria or specific antibodies for Treponema pallidum or herpesviruses. In other instances, an infectious disease may not be diagnosed with certainty in a histological section but the pattern of inflammatory infiltrates is highly suggestive of an infectious cause. Based on such reaction patterns, the dermatopathologist can advise the clinician to perform cultures or serological investigations or additional molecular biological techniques can be applied to the biopsy specimen in order to identify the pathogens. This article presents skin infections with their histopathological features and highlights diseases that can be diagnosed with certainty in a biopsy and those in which a biopsy is helpful to exclude differential diagnoses or to perform molecular diagnostics on the specimen.

[Skin biopsy of inflammatory skin diseases in childhood-when is it reasonable?]

Compared with adulthood, inflammatory skin diseases are relatively rarely biopsied in children. Apart from the invasiveness of the procedure, the required local anesthesia, and the risks of infection and scarring, the psychological trauma of the operation has a higher impact in childhood. If a biopsy is performed, expectations towards the dermatopathology report are high. However, the evaluation of biopsies taken from children is challenging for the dermatopathologist: on the one hand, because the biopsies are often tiny or just superficial shaves and, on the other hand, because criteria for evaluation have mostly been developed from findings in adult biopsy specimens. In children, the immune system is still in the process of maturation and, therefore, infiltrates in the skin may look different from those seen in adults; however, knowledge about that is very limited to date. Moreover, numerous rare genodermatoses may manifest themselves first in childhood and need to be considered in the differential diagnosis while experience with them is often limited. Starting from the clinical presentation, this article presents histopathological features of possible differential diagnoses in order to demonstrate the value or necessity of a skin biopsy in a pediatric patient. In addition, communication with parents and child, methods of local anesthesia and biopsy techniques will be considered.