The PARACELSUS score represents a novel, easily implementable, effective and sensitive diagnostic tool for PG.

Numerous comorbidities and cofactors have been known to influence wound healing processes. In this multicentre study, clinical data of 1 000 patients with chronic leg ulcers from ten specialised dermatological wound care centers were analysed. The patient cohort comprised 567 females and 433 males with an average age of 69·9 years. The wounds persisted on average for 40·8 months and had a mean size of 43·7 cm(2) . Venous leg ulcers represented the most common entity accounting for 51·3% of all chronic wounds, followed by mixed-type ulcers in 12·9% and arterial ulcerations in 11·0% of the patients. Vasculitis was diagnosed in 4·5%, trauma in 3·2%, pyoderma gangrenosum in 2·8%, lymphoedema in 1·7%, neoplasia in 1·0% and delayed post-surgical wound healing in 0·6% of the included patients. In total, 70·5% of patients suffered from arterial hypertension, 45·2% were obese, 27·2% had non-insulin dependent diabetes, and 24·4% dyslipidaemia. Altogether 18·4% suffered from metabolic syndrome. Cofactors and comorbidities of patients with chronic leg ulcers have previously been studied but not in detail. Here, we were able to demonstrate the existence of several potentially relevant cofactors, comorbidities of their associations and geographical distributions, which should be routinely examined in patients with chronic leg ulcers and - if possible - treated.

Summary Pyoderma gangrenosum (PG) is a rare, treatable skin disorder that causes ulcers ‐ usually a single one but sometimes more. It is not contagious. Often it is diagnosed by ruling out other diseases with similar symptoms, and it can be misdiagnosed. The aim of this study, from Germany, was to establish a scoring system that includes symptoms and features that are specific to PG, that could easily be used in clinics to diagnose the disorder. The scoring system, called PARACELSUS, was tested on 60 participants with previously confirmed PG, and a control group of 50 patients with leg ulcers that are not caused by PG. The criteria included in the scoring system relate to how the ulcer looks, how it progresses and which drugs help clear it. The authors conclude that, based on their tests, the PARACELSUS score represents an easily implementable, effective and accurate diagnostic tool for PG.

Bacterial colonisation in wounds delays healing, mandating regular bacterial removal through cleaning and debridement. Real‐time monitoring of the efficacy of mechanical debridement has recently become possible through fluorescence imaging. Red fluorescence, endogenously produced during bacterial metabolism, indicates regions contaminated with live bacteria (>104 CFU/g). In this prospective study, conventional and fluorescence photos were taken of 25 venous leg ulcers before and after mechanical debridement, without use of antiseptics. Images were digitally segmented into wound bed and the periwound regions (up to 1.5 cm outside bed) and pixel intensity of red fluorescence evaluated to compute bacterial area. Pre‐debridement, bacterial fluorescence comprised 10.4% of wound beds and larger percentages of the periwound area (~25%). Average bacterial reduction observed in the wound bed after a single mechanical debridement was 99.4% (p<0.001), yet periwound bacterial reduction was only 64.3%. On average, across bed and periwound, a single mechanical debridement left behind 29% of bacterial fluorescence positive tissue regions. Our results show the substantial effect that safe, inexpensive, mechanical debridement can have on bacterial load of venous ulcers without antiseptic use. Fluorescence imaging can localise bacterial colonised areas and showed persistent periwound bacteria post‐debridement. Fluorescence‐targeted debridement can be used quickly and easily in daily practice.

Our data analysis describes one of the largest compilations of patient cases with the diagnosis of NL worldwide. Besides the well-known association with diabetes mellitus, there are numerous other potentially relevant cofactors and comorbidities that should be considered in the diagnosis and management of NL patients.

Pyoderma gangrenosum (PG) is a rarely diagnosed non-infectious neutrophil ulcerative dermatosis with only limited knowledge on the underlying auto-inflammatory process. To unravel common cofactors and comorbidities in patients with PG we analysed Diagnosis Related Groups (DRG) cases of all inpatients diagnosed with PG in German hospitals in 2012. We received data of 1227 inpatient cases having PG as primary diagnosis and 985 inpatient cases with PG as secondary diagnosis. The ratio of women to men was 2:1, and the most often registered age was 75-79 years. Common comorbidities were arterial hypertension (50·3%), non-insulin-dependent diabetes mellitus (25·1%) and dysfunction of lipid metabolism (10·8%). In sum, 94·8% of the patients suffered from aspects of metabolic syndrome. Other comorbidities were Crohn's disease (4·5%), ulcerative colitis (4·2%), chronic polyarthritis (5·2%), monoclonal gammopathy or myelodysplastic syndrome (2·5%), leukaemia (1·1%) and lymphoma (0·4%). DRG data do not reflect individual patients, but rather patient cases. We described the worldwide largest PG population and confirmed a wide range of potentially relevant and partly not yet described cofactors and comorbidities such as metabolic syndrome.

Although S. aureus is still the most frequently detected bacterium in our wound care center, there has been a shift in the bacterial spectrum from gram-positive towards gram-negative bacteria over the last decade.

Our data show the regional variability of the spectrum of currently detected bacteria in patients with chronic leg ulcers in Germany.