Vasculitis as the basis of cutaneous lesions in Reiter's disease

Updates and Proposed Diagnostic Approach to Psoriasiform Dermatoses

Psoriasiform dermatoses represent a wide array of skin diseases commonly encountered by clinicians and pathologists. While they may present a diagnostic challenge, thorough observation coupled with proper interpretation of subtle additional clinical or histopathologic features provide clues to the correct diagnosis. In this review, we provide updates on emerging entities and develop a systemic approach to establish the pathologic diagnosis, with emphasis on the importance of clinicopathologic correlation.

Reactive arthritis

Reactive arthritis (ReA) is an immune-mediated seronegative arthritis that belongs to the group of spondyloarthropathies and develops after a gastrointestinal or genitourinary system infection. The condition is considered to be characterized by a triad of symptoms (conjunctivitis, arthritis and urethritis) although a constellation of other manifestations may also be present. ReA is characterized by psoriasiform dermatological manifestations that may resemble those of pustular psoriasis and, similar to guttate psoriasis, is a post-infectious entity. Also, the articular manifestations of the disorder are similar to those of psoriatic arthritis and both conditions show a correlation with HLA-B27. These facts have led several authors to suggest that there is a connection between ReA and psoriasis, listing ReA among the disorders related to psoriasis. However, the pathogenetic mechanism behind the condition is complex and poorly understood. Bacterial antigenicity, the type of host response (i.e. Th1/Th2 imbalance) and various genetic factors (i.e. HLA-B27 etc.) play an important role in the development of the disorder. It is unknown whether all the aforementioned factors are part of a mechanism that could be similar to, or share basic aspects with known psoriasis pathogenesis mechanisms.

Cutaneous vasculitis: a review

As the skin is commonly involved in systemic vasculitic disorders as well as those hypersensitivity states whose expression is largely skin-confined, cutaneous vasculitic lesions offer a window to diagnosis and a ready source of accessible tissue for biopsy. In this review, we discuss the pathologic manifestations of chronic vasculitic syndromes such as granuloma faciale and erythema elevatum diutinum; IgA-associated vasculitis including Henoch-Schonlein purpura; vasculitis seen in the setting of cryoglobulinemia and hypergammaglobulinemia of Waldenstrom, hereditary deficiencies of complement, and IgA deficiency; those leukocytoclastic vasculitides resulting from hypersensitivity reactions to drug, chemical and foodstuff ingestion; and those vasculitides seen in patients with systemic diseases such as polyarteritis nodosa, rheumatoid arthritis, mixed connective tissue disease, systemic lupus erythematosus, Sjogren's syndrome, relapsing polychondritis, Behcet's disease, Wegener's granulomatosis, and allergic granulomatosis of Churg and Strauss.

A possible association between Chlamydiae psittacci infection and temporal arteritis

Some arguments are in favor of the role of Chlamydia in the pathogenesis of atherosclerosis and some vasculitis. Illustrating this possible relation, we report the case of a patient developing consecutively a Chlamydia psittacci infection and a temporal arteritis. A 73-year-old woman, with no significant medical history, was hospitalized for constitutional symptoms. Three weeks before, she had described fever and sore throat of two days' duration. Since that time, she had remained exhausted and developed a mild intermittent claudication of the jaws. Clinical examination was poor. A biological inflammatory syndrome was noticed. Chest X-ray revealed bilateral interstitial opacities. The titer of anti-C. psittaci antibodies was significant (positive 1g G at 1/2048). Soon after initiation of doxycycline, a temporal arteritis biopsy was performed, due to the persistence of clinical symptoms and high inflammatory syndrome, conclusive for the diagnosis of temporal arteritis. Corticotherapy was added to antibiotic therapy, resulting in the decrease of inflammatory syndrome and an improvement in the general status of the patient. X-ray opacities decreased in three weeks. Serological control after three months showed a decrease of the titer of anti-C. psittacci antibodies to 1/256, confirming the initial diagnosis of Chlamydia pneumopathy. Our observation could provide one more argument for the role of bacteria-like Chlamydia in the pathogenesis of vascular diseases. Prospective seroepidemiological and molecular biology studies could allow us to clarify the association between Chlamydia infections and inflammatory vasculitis-like temporal arteritis.

Treatment of keratoderma blennorrhagicum with tazarotene gel 0.1%

We report near clearing of keratoderma blennorrhagicum following topical application of tazarotene gel 0.1%. This is the first report detailing the use of tazarotene gel for this purpose.

[Pathology of large vessel vasculitides]

INTRODUCTION

Vasculitides can be classified according to the size of the involved vessels. The pathological patterns of large vessel vasculitides are presented here.

CURRENT KNOWLEDGE AND KEY POINTS

They concern Buerger's disease, temporal arteritis, Takayasu's disease, Behçet's disease, infectious arteritides, rheumatologic and miscellaneous diseases. Buerger's disease is a thrombotic arteriopathy with no arterial wall involvement. Temporal arteritis and Takayasu's disease belong to the group of giant cell arteritides. In temporal arteritis, the inflammation is prominent in the internal part of the media and is aggressive for the arterial wall. In Takayasu's disease, the external part of the media is prominently involved. The fibrous thickening of the arterial wall with stenosis is characteristic. Behçet's disease can involve the large arteries with a risk of arterial rupture. Infectious arteritides are not unfrequent in vascular surgery and in previous arterial lesions. Rheumatologic diseases can result in aortitis with aortic incompetence.

FUTURE PROSPECTS AND PROJECTS

These diseases have pathological characteristics which contribute to diagnosis. However, a clearcut classification of vasculitides will come from the precise knowledge of their etiology.

A distinctive cutaneous reaction pattern indicative of infection by reactive arthropathy-associated microbial pathogens: the superantigen ID reaction

The two major cutaneous expressions of infective states are infections of the skin by viable organisms and immunological responses to nonviable microbial antigens or, in the case of molecular mimickry, their human analogues. These immunological responses are designated as cutaneous id reactions, and manifest a histomorphology similar to that seen at the primary infective site. This study presents the clinical and histological findings in 16 patients who developed skin eruptions associated with extracutaneous or systemic infections. There was a striking female predominance; patients ranged in age from 10 to 78 years. The majority of cases manifested skin lesions which clinically resembled Sweet's syndrome, erythema multiforme and/or erythema nodosum. Fever, arthralgia, oligoarthritis, mucosal ulcers of the mouth and/ or genital tract and uveitis were additional features in some cases. Isolated clinical presentations included a petechial rash in a stocking and glove distribution, papular dermatitis, a morbilliform eruption and annular erythema. Among the medical and family histories were atopy and stigmata associated with connective tissue disease (CTD). Two patients were ingesting drugs with known immune dysregulating properties. Skin biopsies showed focal lymphocytic interface dermatitis, a diffuse interstitial histiocytic infiltrate, and a mononuclear cell predominant vascular reaction which in some cases represented vasculitis by virtue of manifesting concomitant luminal or mural fibrin deposition. Eosinophils, eczematous alterations, and papillary dermal edema were identified in a minority of cases. All patients had evidence of a prior or concurrent infection, based on either positive IgM serology for specific microbes or cultures. Among the implicated pathogens were cytomegalovirus, parvovirus B19, streptococcus, mycoplasma, klebsiella, and Borrelia burgdorferi. All of these organisms are among those associated with reactive arthritis, a phenomenon that was seen in some cases. The histology suggested florid cell mediated immunity (CMI), which the authors attributed to the superantigen properties held by the aforesaid pathogens. Skin lesions and constitutional symptoms resolved quickly with antimicrobial therapy in 7 of 9 cases causally linked to bacteria. Spontaneous resolution occurred in 5 of 6 virally mediated eruptions. The other 4 patients were given topical steroids or prednisone; these included 1 patient with Borrelia burgdorferi infection and 1 patient with radiographic evidence of pneumonia who was never cultured, 1 patient with parvovirus B19 infection, and 1 patient with pneumococcal pneumonia and concomitant sarcoidosis. It is the authors' belief that the eruptions seen in these patients may in part reflect a genetic or iatrogenic predisposition to respond excessively to certain infectious triggers.

The spectrum of skin, mucosa and other extra-articular manifestations

The seronegative spondyloarthropathies appear to be the genetically predisposed host's clinical expression to acute, subacute or chronic reaction to the invasion by environmental microorganisms. In the ensuing days or weeks, depending on the infectious load, clinical manifestations may occur ranging from constitutional complaints such as fever, to a variety of symptoms and/or signs related to the portal of entry-intestinal, genitourinary or respiratory. Within weeks or months, the initial or other target organs, such as the mucocutaneous, ocular and cardiovascular systems, may develop an acute reaction of greater or lesser specificity regarding the triggering agent (oral ulcers, circinate balanitis, erythema nodosum, acute anterior uveitis, pericarditis, heart blocks). Lastly, many years later, a minority of patients, probably those with a large genetic component, exhibit a spectrum of clinical manifestations related to those organs, with a chronic or recurrent course. Acute clinical manifestations--reactive arthritis--are prominent in the initial phase of the clinical spectrum, while chronic manifestations--ankylosing spondylitis--are seen at the other end of the spectrum.

Reactive arthritis

Concepts about reactive arthritis are changing and must embrace consideration of the fact that bacteria or their products are present in the joint, not just at the portal of entry in the gastrointestinal (GI) or genitourinary (GU) tracts. With chlamydia-associated disease, atypical elementary bodies can be seen in synovium by electron microscopy, and nucleic acids, including RNA, can be found. It is not yet clear if bacterial nucleic acids are present in postenteric reactive arthritis and whether disease courses are predictably different after GI or GU infection. How bacteria are disseminated to joints and local factors, including cytokines that influence their persistence, are under study. Treatment with antibiotics may help some chlamydia-associated reactive arthritis but is not invariably effective.

Anti-Ro/SS-A positivity and heat shock protein antibodies in patients with normal-pressure glaucoma

PURPOSE

To describe the clinical and laboratory findings in 10 patients with normal-pressure glaucoma and anti-Ro/SS-A positivity by enzyme-linked immunosorbent assay (ELISA) and to determine whether that positivity may be related to an autoimmune mechanism for the optic neuropathy.

METHODS

In this prospective study, we evaluated ocular and systemic clinical findings of 10 patients with normal-pressure glaucoma and anti-Ro/SS-A positivity by ELISA, including sicca complex features. Oüchterlony immunodiffusion was performed to confirm the presence of antibodies for Ro/SS-A, and the presence of other serum antibodies and their possible cross-reactivities with Ro/SS-A were investigated.

RESULTS

None of the 10 patients with normal-pressure glaucoma and anti-Ro/SS-A positivity (by ELISA) had clinical or laboratory signs of Sjögren syndrome or other connective tissue diseases. Only one of 10 patients had evidence of anti-Ro/SS-A antibodies by Oüchterlony immunodiffusion. All patients demonstrated serum immunoreactivity to bacterial heat shock protein 60 (hsp60) by Western blotting. Cross-reactivity between bacterial hsp60 and Ro/SS-A was demonstrated by Western blotting. Immunoreactivity to bacterial hsp60 by ELISA was significantly elevated in the sera of patients with normal-pressure glaucoma. Furthermore, patients with either normal-pressure or primary open-angle glaucoma had increased serum immunoreactivity to human hsp60.

CONCLUSIONS

Anti-Ro/SS-A positivity by ELISA in 10 patients with normal-pressure glaucoma was associated with a high level of serum immunoreactivity to bacterial hsp60, which may indicate that their glaucomatous optic neuropathy involves an as yet unidentified autoimmune mechanism. The identification of autoantibodies that react with human hsp60 in patients with normal-pressure and primary open-angle glaucoma may signify a common finding associated with the glaucomatous optic neuropathy process in some patients and appears to be unrelated to intraocular pressure levels.

The clinical and histomorphological features of pityriasis rubra pilaris. A comparative analysis with psoriasis

Pityriasis rubra pilaris (PRP) is an idiopathic erythematous scaling eruption which can be difficult to distinguish from psoriasis. We explored the clinical features, including background medical illnesses and potential triggers in patients with PRP, and also its histomorphologic spectrum. Patients with PRP were selected by natural language search of dermatopathology databases containing 250,000 cases accessioned over a 3-year period. A detailed medical history was obtained on each patient via office chart review and patient interviews. We compared the histologic findings in skin biopsies from patients with PRP to those of biopsies matched for site and age from control patients with psoriasis. Certain aspects of the clinical presentations encountered in the study group patients have not been previously emphasized, including eruptions compatible with a vesiculobullous disorder in 4 patients. Several patients had evidence of underlying iatrogenic or systemic immune dysregulatory states and certain triggers could be isolated such as emotional stress and prior exposure to microbial pathogens. Histomorphologic features predictive of PRP included follicular plugging, an increased granular cell layer, and acantholysis. While seen in a minority of biopsies of PRP, morphologic discriminators supportive of a diagnosis of psoriasis included neutrophils in the parakeratotic scale crust, and dermal papillae capillary ectasia with vessels lying in direct apposition to the epidermis. Other morphologic features were encountered in biopsies of PRP which have received little emphasis in the dermatopathology literature, including epithelial atrophy, significant dermal inflammation, the presence of eosinophils and plasma cells within the inflammatory infiltrates, an abnormal granular cell layer, and epidermolytic hyperkeratosis, albeit none were statistically signficant predictors of PRP over psoriasis. Nevertheless, their identification emphasizes the varied histologic spectrum of PRP. The almost ubiquitous finding of acantholysis and the presence of an abnormal granular cell layer in many biopsies of PRP suggests that abnormal keratins or defects in the retinol signalling pathway may be of pathogenetic importance.