Cutaneous polyarteritis nodosa: a comprehensive review

Cutaneous manifestations of gastrointestinal disease: part II

The gastrointestinal (GI) and cutaneous organ systems are closely linked. In part I of this continuing medical education article, the intricacies of this relationship were explored as they pertained to hereditary polyposis disorders, hamartomatous disorders, and paraneoplastic disease. Part II focuses on the cutaneous system's links to inflammatory bowel disease and vascular disorders. An in-depth analysis of inflammatory bowel disease skin findings is provided to aid dermatologists in recognizing and facilitating early consultation and intervention by gastroenterologists. Cutaneous signs of inflammatory bowel disease include fissures and fistulae, erythema nodosum, pyoderma gangrenosum, pyostomatitis vegetans, oral aphthous ulcers, cutaneous polyarteritis nodosa, necrotizing vasculitis, and epidermolysis bullosa acquisita. Additional immune-mediated conditions, such as diverticulitis, bowel-associated dermatosis-arthritis syndrome, Henoch-Schönlein purpura, dermatitis herpetiformis, and Degos disease, in which the skin and GI system are mutually involved, will also be discussed. Genodermatoses common to both the GI tract and the skin include Hermansky-Pudlak syndrome, pseudoxanthoma elasticum, Ehlers-Danlos syndrome, hereditary hemorrhagic telangiectasia, and blue rubber bleb nevus syndrome. Kaposi sarcoma is a neoplastic disease with lesions involving both the skin and the gastrointestinal tract. Acrodermatitis enteropathica, a condition of zinc deficiency, likewise affects both the GI and dermatologic systems. These conditions are reviewed with updates on the genetic basis, diagnostic and screening modalities, and therapeutic options. Finally, GI complications associated with vascular disorders will also be discussed.

The vasculitic neuropathies: an update

PURPOSE OF REVIEW

Vasculitic neuropathy is a heterogeneous disorder that usually occurs in systemic diseases, but less commonly appears as nonsystemic vasculitic neuropathy (NSVN). This review is intended to highlight recent developments in the field of vasculitic neuropathies.

RECENT FINDINGS

A Peripheral Nerve Society guideline provides data-driven consensus recommendation on classification of vasculitic neuropathies and diagnosis/treatment of NSVN. NSVN is sometimes accompanied by subclinical inflammation of adjacent skin. Amyotrophic lateral sclerosis with sensory involvement can mimic NSVN. Systemic vasculitides with neuropathy include polyarteritis nodosa, microscopic polyangiitis (MPA), rheumatoid vasculitis, Churg-Strauss syndrome (CSS), and hepatitis C-related mixed cryoglobulinemic vasculitis (MCV). At autopsy, MPA affects limb nerves diffusely, with maximal damage in proximal/middle segments. CSS can be accompanied by antineutrophil cytoplasmic antibodies (ANCAs), but most patients with neuropathy lack ANCAs. Cryoglobulinemic neuropathies are usually caused by vasculitis, irrespective of phenotype. Two randomized trials revealed rituximab to be noninferior to cyclophosphamide for inducing remission in ANCA-associated vasculitis. Many reports also document efficacy of rituximab in MCV.

SUMMARY

Consensus guidelines on NSVN should be evaluated prospectively. MPA-associated vasculitic neuropathy results from vasculitic lesions distributed diffusely throughout peripheral extremity nerves. Rituximab is effective for ANCA-associated and cryoglobulinemic vasculitis with neuropathy.

A Rationale for the Use of F18-FDG PET/CT in Fever and Inflammation of Unknown Origin

This review focuses on the diagnostic value of hybrid F18-FDG Positron Emission Tomography/Computerized tomography (PET/CT) in fever of unknown origin (FUO) and inflammation of unknown origin (IUO). Due to the wide range of possible causes both FUO and IUO remain a clinical challenge for both patients and physicians. In addition, the aetiology of IUO shows the same variation in diseases as the FUO spectrum and probably requires the same diagnostic approach as FUO. There are numerous historically used diagnostic approaches incorporating invasive and non-invasive, and imaging techniques, all with relative high specificity but limited sensitivity. This hampers the generalization of these diagnostic approaches. However, recently published reports show that F18-FDG PET/CT in FUO and IUO has a high sensitivity and a relative non-specificity for malignancy, infection and inflammation. This makes F18-FDG PET/CT an ideal diagnostic tool to start the diagnostic process and to guide subsequent focused diagnostic approaches with higher specificity. In addition, F18-FDG PET/CT has a relative high negative predictive value. Therefore F18 FDG PET/CT should be incorporated in the routine diagnostic work-up of patients with FUO and IUO, preferably at an early stage in the diagnostic process.

Inflammatory nodules of the leg

There is a group of diseases characterized by inflammatory nodules which generally located on the lower leg. They have certain clinical appearances in common, which often makes a differential diagnosis difficult or impossible on clinical grounds alone. There is a great variation in histopathologic appearance, which depends on the duration of the lesions and sites from specimens are obtained for biopsy. Therefore, separating and subclassifying inflammatory nodule lesions of the legs, based on the subtle clinical and histological variation, is not easy. Despite all these difficulties, a specific diagnosis can be made with an adequate clinic-pathologic correlation.

A case of refractory cutaneous polyarteritis nodosa in a patient with hepatitis B carrier status successfully treated with tumor necrosis factor alpha blockade

We describe a patient with refractory cutaneous polyarteritis nodosa (CPAN) with hepatitis B virus (HBV) carrier status who was successfully treated with tumor necrosis factor alpha (TNF-α) blockade, using etanercept, and we review 5 similar cases. We administered etanercept because of the occurrence of repeated flares despite aggressive therapy. C-reactive protein normalization; prednisolone dose-sparing; and absence of any adverse events, including HBV reactivation with nucleotide analogue administration, or renal dysfunction, have been achieved for 8 months. TNF-α blockade should be considered for intractable CPAN.