Generalized livedo reticularis associated with monoclonal cryoglobulinemia and multiple myeloma

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.

Bar Code Reader - an algorithmic approach to cutaneous occluding vasculopathies? part II medium vessel vasculopathies

Aims

Classifications of occluding vasculopathies (except vasculitis [1]) may exhibit some difficulties. Firstly, classifications may follow different principles, e.g. clinicopathologic findings, etiology or pathogenesis. Secondly, authors may not distinguish between vasculitis and occluding vasculopathies. Thirdly, occluding vasculopathies are systemic diseases. Organ‐specific variations make morphologic findings difficult to compare. Moreover, subtle changes are recognized in the skin, but may be invisible in other organs. Our aim was to use the skin and subcutis as a tool and clinicopathological correlation as the basic process for classification.

Methods and results

We first differentiate in the skin between small and medium vessel occluding vasculopathies. Here we focus on medium vessel‐occluding vasculopathies. In the second step we differentiate the vessel subtypes. In the final step, we differentiate according to the time point of the coagulation/reorganization process and the involved inflammatory cells/stromal features. By applying the same procedure to the various entities and visualizing the findings in the style of bar codes, the overlaps and differences in the clinical picture as well as the histopathology become more apparent.

Conclusions

Occluding vasculopathies are often not separate entities, but reaction patterns and epiphenomena. Distinguishing them from vasculitides is crucial because of the differences in pathogenesis, therapeutic approach and prognosis.

Eruptive ulcerative follicular spicules heralding progression of smoldering multiple myeloma

Herein, we describe a patient with immunoglobulin G (IgG)-lambda smoldering multiple myeloma with translocation t(4:14) who developed widespread ulcerative horny-like spicules, heralding rapid progression to overt myeloma requiring aggressive chemotherapy and autologous stem cell transplantation. The serum abnormal immunoglobulin in the blood was cryoglobulin, which typically precipitates in the tissues at low temperatures causing inflammation and tissue damage. Histopathological changes, observed in lesions at different evolutionary stages, evidenced columns of horny-like eosinophilic homogeneous material, immunoreactive for IgG lambda, protruding from the dilated and/or distorted follicular openings or acrosyringia and small vessel thrombotic vasculopathy and vasculitis in concert with an inflammatory neutrophilic and lymphocytic reaction. Biochemical investigations on material from a spicule and ulcero-necrotic lesion revealed cryoprecipitates containing IgG-lambda with electrophoretic characteristics identical to those of the serum dysprotein. Our findings suggest that the formation of spicules and development of ulcerative lesions are a part of the same clinical spectrum where the cold-dependent precipitation of the immunogenic dysprotein, both in the skin vessels and hair follicle infundibula, play a major pathogenetic role. Whether this highly characteristic paraneoplastic dermatosis can identify patients with high-risk cytogenetic abnormalities and be incorporated into prognostic models, applicable early on in the course of myeloma, warrants further investigation.

Nomenclature of Cutaneous Vasculitis: Dermatologic Addendum to the 2012 Revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides

OBJECTIVE

To prepare a dermatologic addendum to the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides (CHCC2012) to address vasculitides affecting the skin (D-CHCC). The goal was to standardize the names and definitions for cutaneous vasculitis.

METHODS

A nominal group technique with a facilitator was used to reach consensus on the D-CHCC nomenclature, using multiple face-to-face meetings, e-mail discussions, and teleconferences.

RESULTS

Standardized names, definitions, and descriptions were adopted for cutaneous components of systemic vasculitides (e.g., cutaneous IgA vasculitis as a component of systemic IgA vasculitis), skin-limited variants of systemic vasculitides (e.g., skin-limited IgA vasculitis, drug-induced skin-limited antineutrophil cytoplasmic antibody-associated vasculitis), and cutaneous single-organ vasculitides that have no systemic counterparts (e.g., nodular vasculitis). Cutaneous vasculitides that were not included in the CHCC2012 nomenclature were introduced.

CONCLUSION

Standardized names and definitions are a prerequisite for developing validated classification and diagnostic criteria for cutaneous vasculitis. Accurate identification of specifically defined variants of systemic and skin-limited vasculitides requires knowledgeable integration of data from clinical, laboratory, and pathologic studies. This proposed nomenclature of vasculitides affecting the skin, the D-CHCC, provides a standard framework both for clinicians and for investigators.

Paraprotein deposits in the skin

Cutaneous manifestations secondary to paraprotein deposits in the skin include a group of different disorders that although rare, may be the first clinical manifestation of the underlying hematologic dyscrasia. In this article we review the clinical manifestations and histopathologic findings of the processes that result from specific deposition of the paraprotein in different structures of the skin. Paraneoplastic processes frequently associated with hematologic malignancies will not be covered in this review. Some of the disorders included here result from deposition of the intact paraprotein in the skin, whereas in other cases the lesions are due to deposition of modified paraproteins in the form of amyloid substance, cryoglobulins, or crystalglobulins. Cutaneous amyloidoma refers to nodular dermal deposits of amyloid derived from immunoglobulin light chains produced by local plasma cells in the absence of systemic amyloidosis. Dermatologists and dermatopathologists should be aware of the clinical and histopathologic features of these rare disorders because sometimes the cutaneous lesions are the first sign of an underlying silent hematologic malignancy with paraproteinemia.

Skin manifestations of internal disease

Internal diseases can manifest in a myriad of skin dermatoses ranging from single disorders such as calciphylaxis, cryoglobulinemia, amyopathic dermatomyositis, and Raynaud phenomenon, to spectrum disorders such as the neutrophilic dermatoses and morphea. In this article the underlying causes, triggering events, constitutional symptoms, clinical features and presentations, appearance at various stages, and pathogenesis are described. The course of the diseases and probable healing outcomes are outlined. Finally, examination and diagnostic methods, and therapies and treatments are provided.

[Livedo: from pathophysiology to diagnosis]

PURPOSE

We propose a diagnostic approach when facing a livedo. First, the pathophysiology of the livedo is reviewed using key articles barely quoted in the literature. Then the topic is handled in two ways. Figures and tables allow a rapid reading convenient "at the patient's bedside". The subject is also reviewed thoroughly, and we emphasize the intricacy of the various pathophysiological mechanisms involved for each livedo's related disease. Diseases associated with livedo are then briefly described with emphasis on the key diagnostic features and prevalence. Usefulness of the main diagnostic procedures is discussed.

CURRENT KNOWLEDGE AND KEY POINTS

A livedo is a usually purplish-blue erythema, reticulated (small and complete meshes) or racemosa (large broken circular segments) which is related to a slowdown of the blood flow in the dermic venules. These venules form adjacent circles communicating with each other, parallel to the skin surface. The blood flow slowdown may be due to a local vasoconstriction (vasomotor livedo) or to an arteriolar occlusion. Arteriolar occlusion may be related to blood abnormalities (thrombosis, high viscosity, embolus) or to increased parietal thickness (vasculitis, calcic deposition, intimal hyperplasia). It is not always possible to clinically distinguish a vasomotor livedo from those associated with diseases. Diagnostic procedures should be oriented by the medical history, the features of the livedo, and associated symptoms. Usefulness of the skin biopsy is usually limited to the situations where the livedo is infiltrated or necrotic.

FUTURE PROSPECTS AND PROJECTS

To raise controversy about their importance and implications, some pathophysiological data are presented: intimal pseudohyperplasia in Sneddon's syndrome and antiphospholipid syndrome, and white cell activation in essential thrombocythemia.