The differing pathophysiologies that underlie COVID-19-associated perniosis and thrombotic retiform purpura: a case series.

BACKGROUND: There are two distinctive acral manifestations of COVID-19 embodying disparate clinical phenotypes. One is perniosis occurring in mildly symptomatic patients, typically children and young adults; the second is the thrombotic retiform purpura of critically ill adults with COVID-19. OBJECTIVES: To compare the clinical and pathological profiles of these two different cutaneous manifestations of COVID-19. METHODS: We compared the light microscopic, phenotypic, cytokine and SARS-CoV-2 protein and RNA profiles of COVID-19-associated perniosis with that of thrombotic retiform purpura in critical patients with COVID-19. RESULTS: Biopsies of COVID-19-associated perniosis exhibited vasocentric and eccrinotropic T-cell- and monocyte-derived CD11c+ , CD14+ and CD123+ dendritic cell infiltrates. Both COVID-associated and idiopathic perniosis showed striking expression of the type I interferon-inducible myxovirus resistance protein A (MXA), an established marker for type I interferon signalling in tissue. SARS-CoV-2 RNA, interleukin-6 and caspase 3 were minimally expressed and confined to mononuclear inflammatory cells. The biopsies from livedo/retiform purpura showed pauci-inflammatory vascular thrombosis without any MXA decoration. Blood vessels exhibited extensive complement deposition with endothelial cell localization of SARS-CoV-2 protein, interleukin-6 and caspase 3; SARS-CoV-2 RNA was not seen. CONCLUSIONS: COVID-19-associated perniosis represents a virally triggered exaggerated immune reaction with significant type I interferon signaling. This is important to SARS-CoV-2 eradication and has implications in regards to a more generalized highly inflammatory response. We hypothesize that in the thrombotic retiform purpura of critically ill patients with COVID-19, the vascular thrombosis in the skin and other organ systems is associated with a minimal interferon response. This allows excessive viral replication with release of viral proteins that localize to extrapulmonary endothelium and trigger extensive complement activation.

Benign atrophic papulosis (Köhlmeier-Degos disease): the wedge-shaped dermal necrosis can resolve with time.

BACKGROUND: Atrophic papulosis is a rare thrombo-occlusive disease, characterized by the appearance of multiple atrophic porcelain-white skin papules, with a surrounding erythematous rim, which are histologically consisting of wedge-shaped necrosis of the dermis. OBJECTIVE: It consists of two variants: (i) the benign atrophic papulosis (BAP) only involving the skin and (ii) the malignant atrophic papulosis (MAP) also involving several internal organs with a cumulative five-year survival rate of approx. 55%. While the probability of only having a BAP at onset is approximately 70%, increasing to 97% after 7 years of monosymptomatic cutaneous course, no close long-term follow-up of the development of the skin lesions has been reported. METHODS: We present a precise visual documentation of the evolution of the disseminated skin lesions in a female patient with BAP spanning over two decades. RESULTS: A considerable improvement and/or clinical resolution of the majority of the lesions disputing the scarring character of the atrophic porcelain-white skin papules has been detected. CONCLUSION: BAP not only exhibits an excellent prognosis, but resolution of lesions can also occur after a considerable period of time.

Laparoscopy shows superiority over endoscopy for early detection of malignant atrophic papulosis gastrointestinal complications: a case report and review of literature.

BACKGROUND: The malignant form of atrophic papulosis (Köhlmeier-Degos disease) is a rare thrombo-occlusive vasculopathy that can affect multiple organ systems. Patients typically present with distinctive skin lesions reflective of vascular drop out. The small bowel is the most common internal organ involved, resulting in considerable morbidity and mortality attributable to ischemic microperforations. Determination of the presence of gastrointestinal lesions is critical in distinguishing systemic from the benign, cutaneous only disease and in identifying candidates for treatment. CASE PRESENTATION: We describe an 18 year old male who first presented with cutaneous atrophic papulosis but became critically ill from small bowel microperforations. He had an almost immediate and dramatic response to treatment. Prior to his presentation with acute abdomen he had upper and lower endoscopy showing areas of nonspecific patchy erythema. At laparotomy, innumerable characteristic lesions with central pearly hue and erythematous border were seen. PubMed was used for a literature search using the keywords malignant atrophic papulosis, Degos disease, endoscopy, laparoscopy and laparotomy. This search yielded 200 articles which were further analyzed for diagnostic procedures and findings. Among the 200 articles we identified only 11 cases in which endoscopy was performed. Results of endoscopy and laparotomy in our patient with malignant atrophic papulosis were compared to those in the literature. Endoscopy of the gastrointestinal tract has shown gastritis and non-specific inflammation whereas laparoscopy shows white plaques with red borders on the serosal surface of the small bowel and the peritoneum. From personal communications with other physicians worldwide, we identified three additional unpublished cases in which endoscopy revealed only minimal changes while laparoscopy showed dramatic lesions. From our experience the endoscopic findings are often subtle and nonspecific, whereas laparascopy or laparotomy will reveal pathognomic lesions on the serosal surface of the intestine. CONCLUSION: Our report contrasts the endoscopic and laparoscopic findings in malignant atrophic papulosis which suggest laparoscopy is the more powerful means of detecting gastrointestinal involvement. Imaging studies may serve as a key indicator of systemic progression. Based on our experience, laparoscopy should be performed when there is a high index of suspicion for gastrointestinal malignant atrophic papulosis, even if endoscopic examination is non-diagnostic or normal.

Eculizumab prevents recurrent antiphospholipid antibody syndrome and enables successful renal transplantation.

Renal transplantation in patients with antiphospholipid antibodies has historically proven challenging due to increased risk for thrombosis and allograft failure. This is especially true for patients with antiphospholipid antibody syndrome (APS) and its rare subtype, the catastrophic antiphospholipid antibody syndrome (CAPS). Since a critical mechanism of thrombosis in APS/CAPS is one mediated by complement activation, we hypothesized that preemptive treatment with the terminal complement inhibitor, eculizumab, would reduce the extent of vascular injury and thrombosis, enabling renal transplantation for patients in whom it would otherwise be contraindicated. Three patients with APS, two with a history of CAPS, were treated with continuous systemic anticoagulation together with eculizumab prior to and following live donor renal transplantation. Two patients were also sensitized to human leukocyte antigens (HLA) and required plasmapheresis for reduction of donor-specific antibodies. After follow-up ranging from 4 months to 4 years, all patients have functioning renal allografts. No systemic thrombotic events or early graft losses were observed. While the appropriate duration of treatment remains to be determined, this case series suggests that complement inhibitors such as eculizumab may prove to be effective in preventing the recurrence of APS after renal transplantation.

Follicular cutaneous squamous cell carcinoma: an under-recognized neoplasm arising from hair appendage structures.

BACKGROUND: Cutaneous squamous cell carcinoma (SCC) with no demonstrable point of epidermal origin is problematic as it raises consideration of metastatic SCC histologically. There are rare case reports and series of SCC arising from the wall of hair follicle structures. Such lesions have been termed follicular SCC (FSCC). OBJECTIVES: To investigate the clinicopathological features of FSCC. METHODS: We prospectively collected cases of follicular SCC over a 5-year period. Follicular SCC is defined as a cutaneous SCC deriving from a pre-existing hair follicle structure. Lesions were considered to represent 'hybrid' SCCs if an interfollicular epidermal origin was also demonstrated; SCCs with > 50% of the origin from interfollicular epidermis were excluded. Histological features and clinical information were evaluated. RESULTS: We identified 61 cases of follicular SCC arising in 60 patients from a database of 5212 cutaneous SCCs encountered over the same time period by the same authors. There were 49 pure follicular SCCs and 12 hybrid lesions. The male to female ratio was 44 : 16; the mean age was 74 years (range 44-93). Follicular SCC represents 1·2% of all primary SCCs. Biopsies of such lesions, if the appendage structure of origin is not represented, are histologically indistinguishable from metastatic SCC. CONCLUSIONS: Recognition of this under-reported form of SCC is essential if an inappropriate diagnosis of metastatic SCC, with potentially harmful and inappropriate therapy and investigation, is to be avoided.

miR-21 and miR-155 are associated with mitotic activity and lesion depth of borderline melanocytic lesions.

BACKGROUND: Expression of microRNAs (miRs) has been shown to be altered in many solid tumours and is being explored in melanoma. The malignant potential of some melanocytic lesions is difficult to predict. We hypothesised that characterisation of miR expression in borderline melanocytic proliferations would lead to the identification of a molecular profile that could be used with known prognostic factors to differentiate lesions with high malignant potential. METHODS: The miR expression profile of melanocytic lesions (benign naevi, malignant melanoma and borderline melanocytic tumours) was evaluated by real-time PCR. RESULTS: PCR analysis revealed primary cutaneous melanomas had an 8.6-fold overexpression of miR-21 and a 7.5-fold overexpression of miR-155 compared with benign naevi (P<0.0001). In situ hybridisation confirmed these results. miR-21 and miR-155 were significantly overexpressed within borderline lesions (P=0.0011 and P=0.0048, respectively). When borderline lesions were categorised by mitotic activity and Breslow thickness, miR-21 was associated with mitotic activity and miR-155 was associated with thickness (P<0.025). Among 14 patients with borderline lesions who underwent sentinel lymph node biopsy (SLNB), positive SLNB was associated with increased miR-21 and miR-155 in the primary lesion compared with lesions with a negative SLNB. CONCLUSION: MicroRNA expression profiles can be used to characterise atypical melanocytic lesions.

The use of antibody to complement protein C5 for salvage treatment of severe antibody-mediated rejection.

Desensitized patients are at high risk of developing acute antibody-mediated rejection (AMR). In most cases, the rejection episodes are mild and respond to a short course of plasmapheresis (PP) / low-dose IVIg treatment. However, a subset of patients experience severe AMR associated with sudden onset oliguria. We previously described the utility of emergent splenectomy in rescuing allografts in patients with this type of severe AMR. However, not all patients are good candidates for splenectomy. Here we present a single case in which eculizumab, a complement protein C5 antibody that inhibits the formation of the membrane attack complex (MAC), was used combined with PP/IVIg to salvage a kidney undergoing severe AMR. We show a marked decrease in C5b-C9 (MAC) complex deposition in the kidney after the administration of eculizumab.

Hydrogel coated mesh decreases tissue reaction resulting from polypropylene mesh implant: implication in hernia repair.

PURPOSE: Use of polypropylene mesh (PPM) in hernia repair is associated with tissue reactivity. We examined, in a rat model, a novel non-biodegradable hydrogel coated PPM which may allow for decreased inflammation and a decreased foreign body reaction. METHODS: Through a dorsal midline incision, a 2 cm × 2 cm section of PPM (either coated or uncoated) was placed on the fascial surface 1.5 cm from the incision on the dorsal wall of Sprague-Dawley rats. At 2 and 12 weeks after placement, the PPM and surrounding tissue were harvested. A board-certified dermatopathologist examined H&E stained slides for fibrosis and foreign body reaction. In addition, tissues were stained for apoptotic cells, oxidative damage, macrophages, fibroblasts, neovascularization and metalloproteases. RESULTS: At 2 and 12 weeks, there was a greater than 95 % decrease in foreign body giant cells in coated PPM samples compared to uncoated; fibrosis was decreased by 50 %. At 2 and 12 weeks, oxidative damage, fibroblast accumulation, apoptosis and macrophages were significantly decreased in coated PPM samples compared to uncoated PPM. CONCLUSION: These results demonstrate that a non-biodegradable hydrogel coating of PPM led to significant reduction in foreign body reaction, oxidative stress and apoptosis compared to uncoated PPM in vivo, and suggest that this coating could be clinically useful in hernia repair.

The role of microvascular injury in the pathogenesis of cutaneous lesions of dermatomyositis.

Although microvascular injury has been postulated as the pathogenetic basis of skeletal muscle injury in dermatomyositis (DM), its role in the genesis of the skin lesions, which are said to be difficult to distinguish light microscopically from systemic lupus erythematosus (SLE) and subacute lupus erythematosus (SCLE), has not been analyzed. The authors' intention was to assess the role of microvascular injury in the pathogenesis of skin lesions in DM, SLE, and SCLE. Light microscopic features of biopsies of lesional skin from 20 patients with myopathic DM and 11 with amyopathic DM were compared to eight lesional skin biopsies from eight patients with SLE and 12 lesional skin biopsies from 12 patients with SCLE. Vascular density was compared in the three groups using an immunohistochemical preparation with an antibody to factor VIII. In 12 biopsies from the DM group, and in 19 of 20 lupus erythematosus (LE) specimens, frozen tissue was available. An indirect immunofluorescence methodology was used to detect C5b-9 deposition, and direct immunofluorescence studies for other immunoreactants were performed in standard fashion. Compared with LE, lesions of DM showed a greater degree of endothelial injury, vascular ectasia, and vascular fibrin deposition; there were no differences between myopathic versus amyopathic DM. C5b-9 deposition in vessels was significantly greater in DM than in LE. The superficial vascular plexus density was reduced in lesions of DM versus LE control groups with the greatest reduction observed in myopathic DM. Epithelial injury and mucin was greatest in myopathic DM. Microvascular injury is the apparent pathophysiological basis of skin lesions in DM. Careful attention to microvascular pathology enables distinction of DM from SLE and SCLE. Indirect immunofluorescence testing using a monoclonal antibody to C5b-9 is a valuable tool to distinguish DM from LE in biopsies of lesional skin.

Drug-induced immune dysregulation as a cause of atypical cutaneous lymphoid infiltrates: a hypothesis.

The authors encountered 22 patients in whom a skin biopsy showed atypical lymphoid hyperplasia and in whom a subsequent drug history showed indigestion of one or more agents before lesional onset. In 13 patients, the biopsy had been performed to rule out a diagnosis of malignant lymphoma, whereas the other nine the clinical impression was that of a drug eruption. Among the more frequently prescribed agents were calcium-channel blockers, angiotensin-converting enzyme (ACE) inhibitors, antidepressants, antihistamines, beta-blockers, benzodiazepines and lipid-lowering agents, all of which are either known to perturb lymphocyte function or have been implicated as a cause of pseudolymphomata. Twelve of the patients were on two or more of these drugs. The effect of drug modulation on the clinical course was assessed. The clinical presentations were as one or more erythematous plaques or multiple infiltrative papules, or as solitary nodules. The patient had been on one or more of the aforementioned drugs from 2 weeks to 5 years before developing the lesions. Resolution of the eruptions occurred in 17 patients within 1 to 32 weeks (mean, 7 weeks) of discontinuing the medication. Five additional patients had complete excision of solitary lesions without recurrence. A history of atopy, autoimmune disease, or previous carcinoma was elicited in five patients. All biopsy specimens showed atypical lymphoid infiltrates, which assumed one or more of the following patterns: mycosis fungoides (MF)-like, a lymphomatoid vascular reaction, lymphocytoma cutis and follicular mucinosis. Based on the histopathology of the biopsied lesions and the clinical course being one of lesional resolution after cessation of drug therapy or excision of a solitary lesion without subsequent recurrence, a diagnosis of drug-associated lymphomatoid hypersensitivity was established in all specimens. A diagnosis of drug-associated pseudolymphoma should be excluded before a diagnosis of cutaneous lymphoma is rendered, and should be considered if the patient is on a drug known to alter lymphocyte function, particularly in the setting of systemic immune dysregulation or multidrug therapy where agent may act synergistically or cumulatively to alter lymphoid function. The authors postulate that the drug may promote an aberrant immune response to an antigen that may be the drug itself or some other stimulus. A skin biopsy may be particularly helpful, as the lesions of drug-associated pseudolymphoma have a morphology distinctive from malignant lymphoma.

Idiopathic perniosis and its mimics: a clinical and histological study of 38 cases.

Perniosis is a term applied to cold-induced painful or pruritic erythematous or violaceous acral papular or nodular lesions. We examined 39 skin biopsies from 38 patients who presented with acral purpuric lesions, suggesting a diagnosis of perniosis clinically or pathologically. The presence of a systemic or extracutaneous disease was established in 17 patients, including 5 with systemic lupus erythematosus (SLE), 3 with antiphospholipid antibodies, in 1 in whom there was underlying HIV disease, 2 with viral hepatitis, 2 with rheumatoid arthritis (RA), 2 with cryofibrinogenemia, 1 with hypergammaglobulinemia, 1 with iritis, and 1 with Crohn's disease. In the other 21 patients, the clinical presentations prompted further studies in 12, which showed a positive antinuclear antibody (ANA) in 10. A diagnosis of idiopathic perniosis (IP) was rendered in all 21 of these patients including those in whom a positive ANA was discovered, based on the absence of any other serological markers, signs, or symptoms indicative of a specific systemic disease complex; many had Raynaud's phenomenon, small joint arthralgias, atopy, or a family history of either connective tissue disease or Raynaud's disease. The histopathology of IP comprised a superficial and deep angiocentric lymphocytic infiltrate with papillary dermal edema and lymphocytic exocytosis directed to retia and acrosyringia. A few cases showed a mild vacuolopathic or lichenoid interface dermatitis, adventitial dermal mucinosis, lymphocytic eccrine hidradenitis, vascular ectasia, and thrombosis confined to dermal papillae capillaries. The biopsies from patients with iritis, RA, and Crohn's disease showed a granulomatous vasculitis and a granuloma annulare-like tissue reaction. The biopsies from the patients with SLE, cryofibrinogenemia, primary antiphospholipid antibody syndrome, and hypergammaglobulinemia shared a similar histopathology comprising an interface dermatitis, superficial and deep angiocentric and eccrinotropic lymphocytic infiltrates, vascular ectasia, and dermal mucinosis with prominent involvement of the eccrine coil. Many cases did not show features of IP, namely papillary dermal edema, thrombosis of dermal papillary capillaries, and lymphocytic exocytosis into the retia and acrosyringia. There was frequent vascular fibrin deposition involving reticular dermal vessels. The latter two variables were statistically significant discriminators between IP and in perniotic lesions observed in the setting of underlying systemic disease. With respect to the latter, some cases occurred in the setting of cold exposure and were designated by us as "secondary perniosis" (SP), whereas others showed no specific association with cold exposure and were designated as perniotic mimics (PMs) based exclusively on the gross and microscopic morphology of the lesions.

Subacute cutaneous lupus erythematosus arising in the setting of calcium channel blocker therapy.

After 6 months to 5 years of calcium channel blocker (CCB) therapy for arterial hypertension, nine patients developed photoinduced annular or papulosquamous eruptions consonant clinically with subacute cutaneous lupus erythematosus (SCLE). Four patients were receiving diltiazem, four received verapamil, and one was taking nifedipine. Serology showed antinuclear antibodies (ANA) in seven of nine patients, anti-Ro antibodies in five, and anti-La antibodies in five, with three patients having only anti-La antibodies. Skin biopsy specimens in all nine patients were held to be characteristic of SCLE based on light microscopy, direct, and indirect immunofluorescence. The CCB was discontinued in all; in 8 patients in whom the CCB was stopped, the eruption resolved. A proposed mechanism by which the CCBs may have precipitated the eruptions is offered.

Granuloma annulare and necrobiosis lipoidica tissue reactions as a manifestation of systemic disease.

Granuloma annulare (GA) and necrobiosis lipoidica (NL) are generally considered to be idiopathic cutaneous palisading granulomatous dermatitides. There are sporadic reports of such lesions occurring in patients with coexistent systemic diseases other than diabetes mellitus. Having encountered 49 patients whose skin biopsies showed GA or NL lesions in the setting of extracutaneous disease, the authors set out to assess their clinical and histopathological findings to determine if any parameters were predictive of underlying systemic disease. Fifty-two skin biopsies from 49 patients having either GA or NL in whom there was a clinical history of an associated systemic disease were analyzed by light microscopy. The main systemic disease associations were rheumatologic, endocrine, hematologic, infectious, and inflammatory bowel diseases, ANCA positive vasculitic syndromes, and sarcoidosis. The clinical and histomorphological features were compared with those of a control group of patients whose skin biopsies showed GA or NL and in whom there was no history of extracutaneous disease. For the systemic disease group, patients were selected either retrospectively or prospectively from 160,000 cases accessioned in a 24-month period in the dermatopathology databases of Pathology Services, Inc (Cambridge, MA) and Central Medical Laboratories (Winnipeg, Canada). All systemic disease cases from the former service were analyzed blindly by the second author and from the latter service were analyzed blindly by the first author. Patients in the control group were obtained retrospectively from the Pathology Services Inc. database by the authors. The location of the lesions was atypical in 30 of 34 biopsies from systemic disease patients with a GA tissue reaction versus 10 of 22 biopsies of GA in the control group (P = .001). Six of 18 biopsies from patients with NL tissue reactions in the systemic disease group showed an atypical location, versus only 1 of 9 biopsies of NL from the control group (P = .19). The clinical diagnostic considerations were much broader in the systemic disease group versus the control group and included vasculitis, panniculitis, and connective tissue diseases including morphea in the former. In 22 of 34 GA biopsies and 16 of 18 NL biopsies from the systemic disease group, an active vasculopathy of leukocytoclastic, granulomatous, or thrombogenic subtypes was demonstrable. None of the GA or NL biopsies from the control group showed a similar active vasculopathy. An active vasculopathy was predictive of systemic disease in patients having either a GA-like or an NL-like tissue reaction (P < .001). Fifteen of 34 GA and 7 of 18 NL biopsies in the systemic diseases group showed extravascular neutrophilia in contrast to 3 of 22 GA (P = .02) biopsies and 2 of 9 NL (P = .33) biopsies in the control group. The finding of an active vasculopathy in a skin biopsy specimen showing a GA- or NL-like tissue reaction, particularly in the setting of an atypical clinical presentation both with respect to the location and appearance of lesions, should prompt consideration of an underlying systemic disease, as should extravascular neutrophilia in a skin biopsy showing a GA-like tissue reaction.

Atypical pigmentary purpura: a clinical, histopathologic, and genotypic study.

BACKGROUND: The pigmentary purpuras (PPs) are a heterogeneous group of dermatoses defined by specific clinicopathologic features but sharing, at the light microscopic level, superficially disposed dermal lymphocytic infiltrates and hemorrhage. The term atypical pigmentary purpura (APP) is used by the authors in reference to cases of PP in which individual lesions, although clinically presenting as PP, show morphological features typically associated with mycosis fungoides (MF) including Sezary cells and epidermotropism. The integrated concept of lymphocyte atypia and PP is a confusing and enigmatic one to which reference in the literature has been previously made. Specifically, there are reports of PP presaging fully evolved MF, lymphoid atypia has been identified in lesions of routine PP and MF with purpuric features has been described. The clinical, light microscopic, and genomic features of biopsied lesions showing pathological features of APP and which clinically were consistent with PP is explored. DESIGN: The light microscopy of skin biopsy specimens from 34 patients with a pathological diagnosis of APP was correlated to medical and drug histories. In 14 cases, adequate tissue was present in the paraffin blocks to allow DNA extraction. The polymerase chain reaction (PCR) was used in these 14 cases to explore for rearrangement of the T-cell receptor. Fisher's exact test and pair wise exact tests were used to assess the significance of histological differences between cases determined by dinical features to be of MF- or drug-related origin, or to be idiopathic in nature. RESULTS: Of 34 patients, 7 were held to have MF related PP; specifically these patients had violaceous, infiltrative, variably purpuric plaques on trunk, buttocks, and thighs accompanied by typical PP lesions which occurred either concomitant to or preceded the MF lesions. In 10 cases, a diagnosis of idiopathic PP was made whereby the clinical presentation was characteristic of PP; there were no concomitant lesions suspicious for MF and a drug-based origin was excluded. A drug-based origin was established in 17 patients based on lesional onset related to initiation (5 patients) and/or resolution after discontinuation (12 patients) of drugs including calcium channel blockers, lipid-lowering agents, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, antihistamines, antidepressants, or analgesics. There was considerable overlap histologically between all 3 groups including the degree of lymphoid atypia in the dermis, the presence of dermal-based Sezary cells, the degree and pattern of epidermotropism, the paucity of other inflammatory cell elements, and the presence of laminated dermal sclerosis. Morphological features predictive of MF related APP over the other 2 groups were intraepidermal lymphocytes which were more atypical than the dermal-based infiltrate. Intraepidermal Sezary cells were less frequent in biopsies of drug-related APP relative to idiopathic PP (IPP) and MF related PP. PCR studies conducted in 14 cases (2 cases of MF, 6 cases of drug-related APP, and 6 cases of IPP) revealed clonality in 2 cases of drug-related APP and 2 cases of IPP; the 2 studied MF-related cases did nor show clonal restriction. CONCLUSION: APP should not be equated with purpuric MF; it is not necessarily a precursor lesion of MF, and may be of drug-based origin. Clinical features are critical to the final assessment because there is overlap pathologically in the 3 clinical subtypes of APP.

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

The cutaneous lesions of Reiter's disease (RD) and pustular psoriasis (PP) are said to be histologically similar and often indistinguishable. We encountered three cases of RD in which biopsy specimens of lesions clinically compatible with keratoderma blenorrhagicum showed a pustular psoriasiform tissue reaction in conjunction with a subjacent superficial leukocytoclastic vasculitis (LCV). In an attempt to ascertain if these changes were distinctive and unique to cutaneous RD, the incidence of such changes in lesions of PP was examined using light microscopy and immunohistochemistry. The role of chlamydial infection in the pathogenesis of the observed vascular changes also was explored by assessing for the presence or absence of vascular deposition of chlamydial antigen in cutaneous RD compared with that in a control group that included cases of LCV and PP. In addition to conventional light microscopic analysis, immunoperoxidase studies to identify immunoglobulin deposition were performed on formalin-fixed, paraffin-embedded tissue from two of three patients with RD and on skin biopsy specimens from 11 patients with PP. Direct immunofluorescence (DIF) studies with antibodies to immunoglobulin (Ig)G, IgM, IgA, C3, and chlamydial antigens were performed on frozen tissue from one patient with RD, two patients with PP, three patients with LCV, one patient with nonspecific dermatitis, and one patient with Behçet's disease, who had a high antichlamydia antibody titer. All three specimens of RD showed a pustular psoriasiform diathesis in conjunction with a subjacent superficial LCV that was of maximal intensity in the dermal papillae capillaries. Through an immunoperoxidase technique performed on formalin-fixed tissue, the RD cases for which tissue was available for study demonstrated Ig deposition in injured blood vessels; using the same technique one of 11 PP biopsy specimens showed vascular Ig deposition in concert with LCV. This patient's biopsy was from a lesion of drug-induced LCV. None of the other specimens showed either light microscopic or immunohistochemical evidence of vasculitis. In the one specimen of RD studied by DIF, vascular deposition of IgG, IgM, C3, chlamydia heat shock protein 60 (CHSP60), and chlamydia-specific lipopolysaccharide (LPS) was observed. In the two specimens of PP studied, vascular deposition of C3, fibrin, CHSP 60, and chlamydia-specific LPS was not observed. Two specimens of LCV and the one specimen of dermatitis with concomitant nonspecific vascular injury showed vascular Ig and C3 deposition; in contrast, no vascular deposition of CHSP 60 or chlamydia-specific LPS was observed.(ABSTRACT TRUNCATED AT 400 WORDS)

The cutaneous manifestations of human parvovirus B19 infection.

The prototypical cutaneous manifestations of human parvovirus B19 (B19) infection include a petechial eruption in a glove and stocking distribution, reticular truncal erythema, and the "slapped cheek" sign. An association with connective tissue disease (CTD) stigmata has recently been made. The clinical and dermatopathologic findings in 14 patients whose skin lesions were accompanied by serological evidence of B19 infection or documentation of B19 genome in lesional skin are presented. The authors encountered skin biopsy specimens from 14 patients who presented with skin eruptions accompanied by clinical signs or serology suggestive of antecedent B19 infection. Clinical findings were correlated to the light microscopic appearance of the lesions and the presence of B19 genome in lesional skin. The study group comprised 9 women, 3 men, and 2 boys. Eruptions characteristic of fifth disease, including the slapped cheek sign, reticulated truncal erythema, and acral petechiae, were present in 3 patients, 1 of whom later developed granuloma annulare. The other patients had atypical clinical presentations comprising an asymptomatic papular eruption (2), an eruption clinically resembling Sweet's syndrome (3), myopathic dermatomyositis (DM) (2), lupus erythematosus (LE)-like syndromes (2), and lower-extremity palpable purpura (2). Skin biopsy specimens in 12 cases showed interstitial histiocytic infiltrates with piecemeal fragmentation of collagen and a mononuclear cell-predominant vascular injury pattern. Other features included an interface dermatitis, eczematous alterations, and papillary dermal edema. Lesions with features of DM or LE also showed mesenchymal mucinosis, whereas a biopsied lesion of palpable purpura showed leukocytoclastic vasculitis (LCV). Immunofluorescent testing showed a positive lupus band test (LBT) with epidermal IgG and C5b-9 decoration in 1 patient with a systemic LE-like illness, whereas the DM patients had negative LBTs and vascular C5b-9 deposition typical for DM. Skin biopsy specimens from 11 patients, including those whose presentations resembled LE and DM, were positive for B19 genome. The dermatopathology of B19 infection suggests tissue injury mediated by delayed-type hypersensitivity, by antibody-dependent cellular immunity directed at microbial antigenic targets in the epidermis and endothelium, and by circulating immune complexes in the setting of LCV. These mechanisms appear to generate a clinical and histopathological picture that recapitulates that of CTD.

Differential expression of the bcl-2 oncogene in human basal cell carcinoma.

The bcl-2 protein increases cell longevity and reduces apoptosis. Expression of the bcl-2 oncogene is reported in certain low grade neoplasms including basal cell carcinomas (BCCs). The authors postulated that the indolent variants of BCC, namely, the superficial and circumscribed subtypes, might exhibit greater bcl-2 expression than their aggressive counterparts, and used a monoclonal antibody to identify its protein product in formalin-fixed tissue from 30 BCCs. Expression of bcl-2, observed in 28 to 30 BCCs, was greatest in indolent-growth BCCs and weakest in the aggressive-growth variants (P = .005). Variable bcl-2 expression is seen in BCC and may be integral to both its pathogenesis and its biological behavior.