[Practicability of the German guidelines on skin and soft tissue infections]

The guidelines on calculated parenteral initial treatment of bacterial infections in adults from 2018 were the first German language S2k guidelines for these infections. This article summarizes the experiences with respect to their practicality in the clinical routine and the resulting supplementations and comments. In view of the many different terms for soft tissue infections, the guidelines had to first establish some definitions and diagnostic criteria. Among others, the guidelines introduced the provisional term limited phlegmons (phlegmons are usually termed cellulitis in Angloamerican literature) for the frequent initially superficial soft tissue infections with Staphylococcus aureus, which do not always extend to the fascia, in order to differentiate them from erysipelas caused by Streptoccocus, which in contrast to phlegmons always respond to penicillin. The general symptoms present in erysipela are a practical differential criterion. Somewhat more complex are the definitions and recommendations for the severe forms of phlegmon, which involve the fascia and are accompanied by necrosis, so that here the practicality of the guidelines needs to prove its worth over time. The guidelines also give recommendations how to proceed in case of alleged or confirmed hypersensitivity to beta-lactam antibiotics. Currently, relevant guidelines recommend, and it is correspondingly here elaborated, that in acute cases a beta-lactam antibiotic with side chains other than those in the suspected drug may present an alternative without prior testing. Therefore, cefazolin, that does not share any side chains with other beta-lactam antibiotics, could be administered under appropriate precautionary measures. The term cellulitis is avoided in the guidelines. Since it is used frequently, and also for non-infectious dermatoses, the various meanings are discussed and distinguished from each other.

Pathophysiology and clinical manifestations of immune complex vasculitides

Immune complex (IC) vasculitides present inflammations of vessel walls associated with perivascular deposition of immunoglobulins (Igs), mostly ICs. They encompass systemic and skin-limited variants of IgA vasculitis (IgAV), cryoglobulinemic vasculitis (CV), rheumatoid, lupus, and hypocomplementemic vasculitides, serum sickness cutaneous IgM/IgG (non-IgA) vasculitis, and recurrent macular (hypergammaglobulinemic or exertion-induced) vasculitis. Serum sickness and CV fulfill the criteria of a type III hypersensitivity immune reaction as large lattices of the IC precipitate at vessel walls and activate polymorphonuclear neutrophils (PMNs). Immunoglobulin-A vasculitis differs with regard to the causes of perivascular deposition of ICs since here many IgA1 molecules are hypoglycosylated (Gd-IgA1), which appears to facilitate their perivascular deposition in skin and mesangium (via e.g. CD71). The reasons for increased generation of immunoglobulins or formation of IC and their perivascular deposition in either skin or systemic organs are different and not fully explored. A common denominator of OC vasculitides is the activation of PMNs near the vessel wall via Fcy or Fcα receptors. Acute episodes of IgAV additionally require PMNs to become preactivated by IgA1 or by IC already in circulation. This intravascular priming results in increased adherence and subsequently vessel-destructive NETosis when they encounter IgA deposited at the vessel walls. Binding of IgA1 to PMNs in blood stream is associated with increased serum levels of hypogalactosidated IgA1. The characteristic clinical picture of IgAV (and also of so-called IgG/IgM vasculitis) comprises palpable or retiform purpura with a clear predilection for lower legs, probably due to stasis-related reduction in blood velocity, while in other IC vasculitides, additional factors influence the sites of vasculitides. Our knowledge of distinct forms and different pathophysiological pathways of IC vasculitides may lead to in efficacious or targeted therapies. Antibodies to complement components or intestinal budesonide for IgAV are promising agents (the latter suppresses the pathophysiologically related IgA nephropathy by reducing the generation of mucosal IgA.

[Bullous drug reaction after pembrolizumab administration: two case reports]

Severe, blistering, adverse drug reactions involving the skin include Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). Allopurinol, anticonvulsants, sulphonamide antibiotics and non-steroidal anti-inflammatory drugs in the oxicam class have been repeatedly described as triggers. Increasingly, immunotherapies are also coming into focus as triggers of severe skin reactions. Two patients with bullous skin symptoms after administration of the checkpoint inhibitor pembrolizumab are presented. As the clinical picture does not always allow an unequivocal classification, a histological assessment is often indispensable.

[Sweet syndrome of childhood with acquired cutis laxa (Marshall syndrome) as primary manifestation of Takayasu arteritis]

A special form of the rare infantile Sweet syndrome (acute febrile neutrophilic dermatosis) is facultative healing in the form of postinflammatory elastolysis with acquired cutis laxa, named "Marshall" syndrome after the authors who first described it. We report the case of a 3-year-old child in whom the cutaneous manifestation led to diagnosis of Takayasu arteritis. Postinflammatory elastolysis with acquired cutis laxa is a clinically relevant cutaneous indicator of life-threatening cardiovascular complications such as aortitis, aortic aneurysm, coronary stenosis and heart failure in children with Sweet's syndrome. Cutis laxa usually precedes cardiac complications or, as in our case, occurs simultaneously; thus, immediate cardiac and rheumatologic examinations are important to initiate systemic therapy with anti-inflammatory and immunomodulatory agents early to prevent complications.

Tickbite-associated chronic pruritic lesions in an Afro-descendant population in the Cauca Department, Colombia. I. Clinical features and impact on health

BACKGROUND

During a health survey in a remote area in southwest Colombia, it became apparent that a high percentage of the population suffered from chronic pruritus in association with high numbers of ticks and tickbites.

OBJECTIVE

To determine the clinical features and severity of tickbite-associated pruritus.

METHOD

At twotime points - 8 weeks apart to account for seasonal effects - a cross-sectional study was conducted encompassing physical examination of the population, histological analysis of skin biopsies, and determining serum for antibodies against spotted fever (SFG) rickettsiae and typhus group (TG) rickettsiae. Ticks were identified using morphological criteria, and infection by rickettsiae was determined by PCR.

RESULTS

About 94.5% of the population (95% CI 92-97%) showed clinical signs of a pruritic arthropod reaction and of chronic pruritus with lichenoid papules and hyper- and hypopigmented nodules on otherwise noninflamed skin. Pruritus markedly impaired the quality of life in terms of sleeping disturbances. No signs for other diseases were observed. Chronic pruritus appeared to be because of repeated tickbites and scratching, but not because of other dermatological or medical conditions. Antibodies against SFG and TG-rickettsiae were detected at 79.0% (95% CI 73-86) and 3.6% (95% CI 0.7-6), respectively. Ticks were identified as Amblyomma cajennense.

CONCLUSION

Remarkably high exposure to tick bites caused an unusually high rate of acute and chronic pruritus and markedly impaired quality of life of the investigated rural community. This underlines the necessity of public health measures and surveillance of rickettsial disease.

[Cutaneous alterations in vasculitides : Part 2: Special aspects of diseases of large, medium and small vessels]

Cutaneous vasculitides present with typical clinical signs depending on the size and distribution of the affected vessels. Since there are no large vessels in the skin, giant cell arteritis and Takayasu's arteritis only rarely lead to cutaneous symptoms. The classical systemic polyarteritis nodosa (PAN) is very rare. More frequent is cutaneous PAN presenting with a typical localized livedo racemosa and palpable subcutaneous nodules. The ANCA-associated vasculitides, which belong to the small vessel vasculitides, usually show systemic involvement and manifest on the skin with a diverse picture. Immune complex vasculitides are characterized by deposition of immunoglobulins on the walls of small vessels. The most common form is IgA vasculitis with the cardinal symptoms of palpable, round or oval and partially branched (retiform) purpura and a clear predilection for the legs. Serum disease is a príme example of systemic immune complex diseases due to large circulating immune complexes. Cryoglobulinemic vasculitis primarily involves small as well as medium sized vessels. Simultaneous involvement of vessels of different sizes is characteristic for vasculitis in systemic lupus erythematosus (SLE), Sjögren's syndrome, rheumatoid arthritis and sarcoidosis. Recurrent macular vasculitis in hypergammaglobulinemia is an episodic macular vasculitis of the small blood vessels. Bacteremic vasculitis of the small vessels (without direct microbial infection of the vessel wall) can typically also affect capillaries of dermal papillae and is usually accompanied by a disseminated intravascular coagulation (DIC). In some cases more than one distinct cutaneous vasculitis can occur in the same patient.

[Cutaneous alterations in vasculitides : Part 1: Nomenclature, classification and correlation between clinical signs and histological features]

The skin is one of the organs most commonly affected by vasculitis and the only one that is open to direct inspection. Cutaneous vasculitis can be part of a systemic vasculitis, a variant restricted to the skin (e.g. systemic and cutaneous IgA1 vasculitis) or an independent cutaneous form (recurrent macular vasculitis in hypergammaglobulinemia, nodular vasculitis). For the nomenclature and classification of cutaneous vasculitides the scheme of the Chapel Hill Consensus Conference can be used and the vessels mainly affected determine the clinical picture of individual forms of vasculitis. Some cutaneous efflorescences and their distribution are so characteristic for certain forms of vasculitis that they provide diagnostic indications or even diagnostic criteria. A palpable purpura on the legs is typical for involvement of postcapillary venules in the context of immune complex vasculitis. If arterioles or venules in the dermis are additionally affected, the clinical presentation is that of plaques with marginal offshoots and central hemorrhagic blisters or necrosis (retiform purpura). In contrast to the purpura in occluding vasculopathies, which shows no or little surrounding erythema, the purpura in vasculitis is accompanied by an inflammatory erythema. In vasculitides of the arterioles and small-caliber arteries in the subcutaneous tissue, visible or only palpable nodules exist surrounded by an irregular livedo or also retiform purpura. Understanding how vasculitis-induced efflorescence arises and the histological manifestations helps their recognition during physical examinations in daily practice and is an important guide in the diagnosis and classification of vasculitides.

Sentinel lymphonodectomy in nonmelanoma skin malignancies

BACKGROUND

Whereas the value of sentinel lymphonodectomy (SLNE) in malignant melanoma is established, experience with SLNE in nonmelanoma skin cancers is limited.

OBJECTIVES

The feasibility of SLNE in nonmelanoma skin tumours is evaluated.

METHODS

Thirty-seven patients with high-risk nonmelanoma skin tumours underwent SLNE: 11 squamous cell carcinomas (SCCs), seven Merkel cell carcinomas (MCCs), five cutaneous lymphomas, eight adnexal carcinomas and six other skin cancers, all clinical stage N0.

RESULTS

In nine patients (four MCCs, two SCCs, three lymphomas) the sentinel lymph nodes (SLNs) showed histological evidence of microinvolvement. In five of these nine patients, radical lymph node dissection (RLND) was performed, revealing further micrometastases in three patients (two SCCs, one MCC). No patient with negative SLN showed tumour dissemination during the follow-up over a mean of 2.5 years (range 2 months to 4.5 years, median 2.4 years).

CONCLUSIONS

Our data provide evidence that SLNE is a minimally invasive and highly sensitive staging tool in selected patients with high-risk nonmelanoma skin cancers.

The predictive value of the sentinel lymph node in malignant melanomas

At the beginning of a lymphogenous metastasizing process in malignant melanomas, the first tumor cells are found in the so-called sentinel lymph node (SLN), defined as the first tumor-draining lymph node. Its removal and histopathological examination enable us to discover metastases of malignant melanomas long before their possibility of detection by any other method. Since the beginning of 1995, we have performed more than 350 gamma-probe-guided sentinel lymphonodectomies (gamma-SLNE), without any clinical evidence of metastases as determined by lymphoscintigraphy. Using gamma-SLNE, the detection and excision of the SLN succeeded in nearly all patients. The SLNs were fixed in formalin, completely cut into 1-mm thin slices and stained for routine H&E histology and with S-100 and HMB-45. In persons with melanomas thinner than 0.75 mm, we never found micrometastases. However, the SLNs were positive in melanomas from 0.76 to 1.50 mm in about 7% of patients, in melanomas from 1.51 to 4.00 mm in about 21% and in tumors thicker than 4 mm in about 44%. In primary melanomas with satellite or in-transit metastases, the SLNs contained metastases in 75% of patients. Normally, a radical lymph node dissection (RLND) follows, as it is considered to be the necessary consequence following detection of tumor cells. The lymph nodes of the RLNDs contained further metastases in about 30% of patients. The probability of the involvement of lymph nodes other than the SLN correlates with the extension of tumor cells in the SLN. During our 4-year-follow-up, we observed only a single lymph node recurrence in a patient with a negative SLN (false negative rate of about 0.4%). The development of systemic metastasis correlates not only with the Breslow tumor thickness, but also with the extent of the involvement of the melanoma metastasis in the SLN. Summarizing, it can be said that gamma-SLNE has revolutionized melanoma surgery. Based on our data, it is absolutely necessary in the staging of malignant melanoma. In our opinion, the existing classification systems for staging lymph node involvement have to be revised in light of the results of SLNE.