Pyoderma gangrenosum: an updated review

Pyoderma gangrenosum with splenic involvement

Pyoderma gangrenosum (PG) is a non-infectious disease characterized by necrotizing, ulcerative, and painful skin. The incidence of PG is approximately 3-10 cases per million people per year. Pyoderma gangrenosum is rarely observed in children, which accounts for less than 4%, but it primarily affects adults between the ages of 25 and 54 years old without gender preference. Here, we present a case report of a 16-month-old toddler diagnosed with pyoderma gangrenous with splenic involvement. The young age of the patient and extracutaneous manifestation are of high interest.

Treatment of pyoderma gangrenosum with thalidomide in a myelodysplastic syndrome case

Thalidomide may be used as a treatment option for pyoderma gangrenosum (PG) and myelodysplastic syndrome (MDS). Herein, we aimed to report a patient who was treated well with thalidomide and whose diagnosis was PG with MDS. A 61-year-old man with painless ecchymotic lesions in his right upper extremity was admitted to the hospital in Isparta, Turkey, in January 2015. The lesions were diagnosed as PG. In his anamnesis, it was found that he was diagnosed with MDS 6 years ago and had been treated with cyclosporine at 2×100 mg for 5 years, which was stopped in January 2015. Aspiration from liver lesion revealed the presence of Mycobacterium tuberculosis, so antituberculosis treatment was started. Bone marrow investigation revealed MDS-refractory anemia with excess blasts (7%). For lesions in bilateral upper extremities, thalidomide treatment was started at 50 mg/d. After 1 month from the initiation of thalidomide treatment, the lesions in upper extremities had disappeared. In the literature, there are some reports of patients with PG who were successfully treated with thalidomide. Our patient is a complicated case who simultaneously has MDS, PG, and tuberculosis infection. The reason for thalidomide usage in our patient was the need of immune modulation without immune suppression. Our patient has tolerated the drug well, and excellent response was obtained after 1 month of initiation of thalidomide treatment. To conclude, thalidomide is a very effective drug acting as an immune modulator, which is useful in the clinical management of both MDS and PG.

Pyoderma Gangrenosum: A Report of 27 Patients

The aim of this study was to document the profile of pyoderma gangrenosum (PG) patients who were treated in our clinic and to compare our patients' clinical and demographic characteristics with those described in the literature to help our understanding of the total burden of PG. A total of 27 (17 women, 10 men) patients with a mean age 48.6 years at diagnosis were included in the study. Seven (25.9%) of them had 3 or more ulcers. The lower extremity was the most common site of occurrence (92.5%). During the study period, 6 patients were admitted twice, and 7 were admitted 3 or more times (range 1 to >10), and the median length of stay was 27 days. A concomitant disease was present in PG patients especially in those between 20 and 40 years of age. Systemic therapy was used in 21 (91.3%) patients, 17 patients were treated with systemic corticosteroids, either alone in 7 patients or combination with other agents in 10 patients. Three of our patients died because of disease or treatment-related complications during the study period. Despite the high (70.3%) percentage of the PG patients with improving disease at the time of discharge, 1 year after hospital discharge, one third of our 27 patients still had PG requiring readmission. In conclusion, none of the current therapies provide satisfying results in all of the patients, and our data indicate a long-standing unmet need for effective therapy for the unexpected course of PG.

Pyoderma Gangrenosum-A New Manifestation of Wilson Disease?

Seventeen year old girl, a known case of Wilson disease presented to us with a non-healing skin ulcer followed by appearance of jaundice, ascites and progressive fatigue of 1 month duration. She was diagnosed to have Wilson disease 5 years back and had been well controlled on d-penicillamine. On enquiry, she was found to be noncompliant with her medication in the preceding 6 months. On examination, she had severe pallor, icterus with moderate ascites and oedema feet. Investigations revealed severe haemolytic anemia and deranged liver function. The lesion was diagnosed to be pyoderma gangrenosum on skin biopsy. The appearance of a cutaneous lesion followed by deterioration in the liver disease and hemolysis suggested uncontrolled Wilson disease as the triggering factor. Chelation therapy improved her haemoglobin and liver function as well as led to healing of the ulcer. We describe pyoderma gangrenosum as a new manifestation of Wilson disease.

Multiple pulmonary cavitary nodules with pyoderma gangrenosum in patient with rheumatoid arthritis

Pyoderma gangrenosum (PG) is a rare ulcerative neutrophilic disorder of skin. Its pulmonary manifestations are uncommon and only less than forty cases have been reported in the literature previously. PG is associated with variable systemic diseases, most commonly inflammatory bowel disease and hematologic malignancies. It reported rarely in rheumatoid arthritis (RA). We report a case of PG lung involvement in patient with RA associated interstitial lung disease. A 66-year-old woman presented with productive cough and recurrent ulcerative lesion on her left ankle. She had a 15-year history of RA associated interstitial lung disease and treated with methotrexate, sulfasalazine, hydroxychloroquine and methylprednisolone. On physical examination, there were a few tender, erythematous subcutaneous nodules ranging from 1 to 3 cm in diameter on her left thigh and left elbow. Anti-neutrophil cytoplasmic antibodies (ANCAs) are negative. Her chest CT scan demonstrated multifocal cavitary consolidations on the background of reticular opacity and honeycombing. Punch biopsy of erythematous nodule on thigh showed neutrophilic abscess with necrotic debris. The skin and lung lesions were rapidly improved with 0.5 mg/kg/day of prednisolone.

Pyoderma gangrenosum induced by episiotomy

We present a patient who developed genital ulceration within hours following episiotomy procedure during a normal vaginal delivery. This was initially treated by the gynaecology and medical team as cellulitis with no improvement. A diagnosis of pyoderma gangrenosum (PG) was made by the dermatology team 12 days later. On further investigation, she was found to be hepatitis C positive. We report this case to highlight the phenomenon of pathergy and frequent misdiagnosis of PG by other medical teams. When a postsurgical wound is not healing despite relevant systemic treatment, the clinician should suspect PG as an early diagnosis and treatment is crucial.

Successful vaginal birth after prior cesarean section in a patient with pyoderma gangrenosum

Pyoderma gangrenosum is an extremely rare chronic cutaneous disease causing severe ulceration. It can be developed after minor trauma or surgical procedure. The typical features mimic acute infection site, however the treatment methods are opposing since pyoderma gangrenosum is improved with the use of corticosteroids, not antibiotic therapy. We here report a patient who had been diagnosed for acute infection after cesarean delivery in 2011 and treated with a number of antibiotics, but failed to recover. The patient had suffered from pain of the disease and also renal failure caused by antibiotics. Ultimately she had been diagnosed as pyoderma gangrenosum and managed successfully with steroids. For her next pregnancy in 2013, we tried vaginal delivery after prior cesarean section and it was uneventful during and after delivery.

Pyoderma gangrenosum: A clinician's nightmare

Pyoderma gangrenosum (PG) is a rare disease and that affecting specifically the sole of the foot, is even rarer. Here, we report the case of a 54-year-old female admitted with a painful ulcer on the sole of the right foot which was initially treated with empirical antibiotics and debridement. The disease was found to spread rapidly after each debridement. The culture reports were negative; rheumatology workup and Doppler study were within normal limits. A clinical suspicion of PG was made and was confirmed with tissue biopsy. She was started on oral steroids following which she dramatically improved. Thus, when a patient presents with a rapidly expanding painful ulcer in a vascular limb that is refractory to antibiotic treatment and exacerbating on debridement, it is imperative to consider the possibility of PG.

Pyoderma Gangrenosum in a Patient with Hereditary Spherocytosis

Pyoderma gangrenosum (PG) is a rare, relapsing cutaneous disease with 4 distinctive clinical manifestations: ulcerative, bullous, pustular, and vegetative lesions. It mainly occurs in adults and is frequently associated with systemic diseases, most commonly inflammatory bowel disease, rheumatologic disease, or hematological dyscrasias. However, there have been no previous reports of PG in a patient with hereditary spherocytosis, a common inherited hemolytic anemia. We report here a unique case of PG in a 15-year-old boy with underlying hereditary spherocytosis.

Pyoderma gangrenosum in an abdominal surgical site: a case report

Pyoderma gangrenosum (PG) is an uncommon, ulcerative skin disease that is often associated with systemic diseases. Herein, we report a development of PG in a surgical site after cholecystectomy that was difficult to discriminate from surgical site infection. The patient was a 74-year-old man who had previously been diagnosed with myelodysplastic syndrome (MDS). Laparoscopic cholecystectomy was planned under diagnosis of cholecystolithiasis, but we converted to open cholecystectomy. The surgical wound was partially erythematous 4 days after surgery. In spite of opening the wound, cleansing it with sterile saline, and administration of antibiotics, inflammation spread with erosion. The clinical manifestations and histopathologic features of biopsy specimen indicated that diagnosis of PG associated with MDS was most likely. Administration of glucocorticoids made a rapid response of skin inflammation. The differential diagnosis of postoperative wound healing complications that were unresponsive to conventional wound local care and antibiotic therapy should include PG, especially in patients with systemic diseases such as MDS.

Pathophysiology of pyoderma gangrenosum (PG): an updated review

Pyoderma gangrenosum is a challenging skin condition to identify and treat because of its multifactorial pathogenesis. It is a rare cutaneous manifestation diagnosed clinically by exclusion of infection, neoplasia, thrombophilia, and other inflammatory conditions. Pathogenetic and treatment studies are scarce. Abnormalities in the function of inflammatory cytokines, the immune system, and neutrophils combined with specific genetic mutations predispose patients to develop this complex disease process. Early recognition of patients at risk for pyoderma gangrenosum, the necessity to improve its early diagnosis, and the future outlook of targeted and personalized therapies relies on the improved comprehension of the complex pathogenesis of pyoderma gangrenosum.

Pyoderma gangrenosum: An important dermatologic condition occasionally associated with rheumatic diseases

Pyoderma gangrenosum (PG) presents with refractory, sterile, deep ulcers most often on the lower legs. Clinically, PG exhibits four types, i.e., ulcerative, bullous, pustular, and vegetative types. PG may be triggered by surgical operation or even by minor iatrogenic procedures such as needle prick or catheter insertion, which is well-known as pathergy. PG is sometimes seen in association with several systemic diseases including rheumatoid arthritis (RA), inflammatory bowel disease, hematologic malignancy, and Takayasu’s arteritis. In particular, various cutaneous manifestations are induced in association with RA by virtue of the activation of inflammatory cells (neutrophils, lymphocytes, macrophages), vasculopathy, vasculitis, drugs, and so on. Clinical appearances of ulcerative PG mimic rheumatoid vasculitis or leg ulcers due to impaired circulation in patients with RA. In addition, patients with PG sometimes develop joint manifestations as well. Therefore, it is necessary for not only dermatologists but also rheumatologists to understand PG.

Pyoderma gangrenosum: challenges and solutions

Pyoderma gangrenosum (PG) is a rare disease, but commonly related to important morbidity. PG was first assumed to be infectious, but is now considered an inflammatory neutrophilic disease, often associated with autoimmunity, and with chronic inflammatory and neoplastic diseases. Currently, many aspects of the underlying pathophysiology are not well understood, and etiology still remains unknown. PG presents as painful, single or multiple lesions, with several clinical variants, in different locations, with a non specific histology, which makes the diagnosis challenging and often delayed. In the classic ulcerative variant, characterized by ulcers with inflammatory undermined borders, a broad differential diagnosis of malignancy, infection, and vasculitis needs to be considered, making PG a diagnosis of exclusion. Moreover, there are no definitively accepted diagnostic criteria. Treatment is also challenging since, due to its rarity, clinical trials are difficult to perform, and consequently, there is no “gold standard” therapy. Patients frequently require aggressive immunosuppression, often in multidrug regimens that are not standardized. We reviewed the clinical challenges of PG in order to find helpful clues to improve diagnostic accuracy and the treatment options, namely topical care, systemic drugs, and the new emerging therapies that may reduce morbidity.

Treatment and nursing of a case of ulcerative colitis complicated with gangrenous pyoderma

Ulcerative colitis (UC) with gangrenous pyoderma has been rarely reported. We report a case of a man who was hospitalized because of anal fistula. We found pus and blood covering the surgeon's gloves out of the anus during operation. There existed some postoperative complications, including fever, bloody purulent stool and expanding belly cankers. The patient was diagnosed with UC by enteroscopy and rectal biopsy, and gangrenous pyoderma by skin pathology with clinical features later. After 44 d of nursing and mesalazine and hormone therapy, the patient's condition improved and belly cankers tended to heal. UC with gangrenous pyoderma has no specific clinical manifestations and pathological changes, which is difficult to diagnose early. More importantly, the disease progresses rapidly and has severe damage, and the medical staff should pay more attention.

Pyoderma gangrenosum: a commonly overlooked ulcerative condition

Background:

Pyoderma ga ngrenosum (PG) is a rare, inflammatory, destructive neutrophilic dermatosis, which mimics other ulcerative conditions.

Materials and Methods:

In a retrospective study based on patients diagnosed with PG over a 3-year period (2010–2013), we evaluated demographics, anatomical sites, number of lesions, subtypes, histopathology, associated conditions, treatment regimens, healing time, and recurrence.

Results:

Of our five patients, there were three males and two females, age ranging between 19 and 58 years (mean age 38 years). Four had single lesions localized to the lower limbs while one had multiple lesions (more than five) over bilateral hands and legs. Ulcerative subtype was observed in all the patients. One exhibited pathergy. Skin biopsies were done in four patients, revealing dense neutrophilic infiltrates in three cases and leukocytoclastic vasculitis in one. Associated systemic diseases were observed in all patients, four having inflammatory bowel disease and one having both systemic lupus erythematosus and anti-phospholipid syndrome. The patients were all treated with systemic corticosteroids either alone or in combination with immunosuppressants (e.g., azathioprine, mycophenolate mofetil, tacrolimus), and wound dressing. Split-thickness skin graft was done in one patient. Complete healing was achieved in all patients, ranging from one to 3 months after diagnosis. No recurrence was reported.

Conclusions:

Systemic corticosteroids, either alone or in combination with steroid-sparing agents are the mainstay of treatment. Should family physicians encounter a rapidly progressing ulcer that has poor response to usual wound management, timely referral to dermatology should be made.

Pulmonary manifestations of pyoderma gangrenosum: 2 cases and a review of the literature

Pyoderma gangrenosum (PG) is a rare ulcerative neutrophilic dermatologic disease that occasionally is accompanied by extracutaneous manifestations, amongst these is pulmonary involvement. The etiology is unknown. More than 50% of PG cases are associated with an underlying systemic disease such as inflammatory bowel disease, rheumatoid arthritis, hematological disorder or malignancy. Extracutaneous manifestations are rare and only 29 cases of pulmonary involvement have been reported previously in the literature. Pyoderma gangrenosum is usually diagnosed in the third to sixth decade, but early debut in childhood is also described. Skin manifestations are usually evident before pulmonary involvement, although primary lung affection is seen. Pulmonary involvement is diagnosed simultaneously or from a few weeks up to several years after the diagnosis of cutaneous PG. The most important differential diagnoses are lung cancer, lung abscess and Wegener's granulomatosis. Histological specimens will exclude these diagnoses. The treatment of PG is immune modulation, but due to the rarity of the disease, only one randomized treatment trials exists [1] and the long term course of PG with pulmonary involvement is unknown. We present two cases of pulmonary manifestations of pyoderma gangrenosum and a review of the literature.

Successful Use of Adalimumab for Treating Pyoderma Gangrenosum with Ulcerative Colitis under Corticosteroid-tapering Conditions

A 52-year-old woman with ulcerative colitis was admitted to our hospital for an ulcerative colitis flare-up under salazosulfapyridine therapy. The symptoms improved with high-dose corticosteroids. After prednisolone was tapered to 10 mg, the frequency of diarrhea increased. The diarrhea was accompanied by joint pain and a skin ulcer with abscess formation, which was diagnosed to be pyoderma gangrenosum. The patient was started on adalimumab. A positive response to the adalimumab therapy was observed after 2 weeks, during which time the ulcerative skin lesion healed completely, however, colonic mucosal healing was achieved at 2 months. Therefore, adalimumab appears to be an effective therapeutic option for patients with ulcerative colitis-associated pyoderma gangrenosum.

Acute scrotal ulcers in typhoid Fever: case report and literature review

Background. In developed countries, typhoid fever is a travel-associated disease that is often overlooked. However, as standard blood and stool culture methods have relatively low sensitivity, diagnosis depends heavily on clinical signs and symptoms and on a high level of suspicion.

Methods. Reported here is the case of an 18-year-old male who presented with fever and acute scrotal ulcers and whose blood cultures were positive for Salmonella enterica serotype Typhi. A review of genital ulcers associated with typhoid fever in the literature is discussed.

Conclusion. This report suggests that typhoid fever is a differential diagnosis of acute genital ulcers.

Intravenous immunoglobulin as salvage therapy in refractory pyoderma gangrenosum: report of a case and review of the literature

Pyoderma gangrenosum is a neutrophilic dermatosis that occurs both as a primary disorder as well as secondary to an underlying disease. Due to its low prevalence there are limited data on therapeutics, particularly in refractory cases. Here, we discuss a case successfully managed with intravenous immunoglobulin and review the supporting literature.

Pyoderma gangrenosum and systemic lupus erythematosus: a report of five cases and review of the literature

Pyoderma gangrenosum (PG) is an uncommon, distinctive cutaneous ulceration which is usually idiopathic, but may be associated with many systemic disorders. The etiopathogenesis of PG is still not well understood. PG is part of the spectrum of the neutrophilic dermatoses and it has been proposed as a prototype of cutaneous autoinflammatory disease. PG usually has a good outcome under immunosuppressive treatment. Although PG has been associated with several systemic diseases, it has rarely been reported in association with systemic lupus erythematosus (SLE). In this article we report five cases of SLE-related PG and review the literature. Our findings support the possible relationship between active SLE and PG, although the mechanism remains unclear. Clinical manifestations, used treatments and outcomes of SLE-related PG do not differ from the described for the general population.

Severe, Steroid-responsive, Myositis Mimicking Necrotizing Fasciitis following Orthopedic Surgery: A Pyoderma Variant with Myonecrosis

Summary:

Postoperative pyoderma gangrenosum is a rare neutrophilic dermatosis that may be confused for necrotizing fasciitis. The inflammatory response is triggered by the trauma of surgery and thus must be managed nonsurgically. Clinical and pathological findings in the 2 diseases can be identical, leading to misdiagnosis and massive surgical defects from the ensuing surgery. This report documents a severe case of postsurgical pyoderma following an elective rotator cuff repair presenting with myositis and myonecrosis. The patient was initially treated as having an infection, which resulted in multiple aggressive surgical debridements. Despite this, the patient continued to deteriorate and was in a critical and hemodynamically unstable condition. Following administration of high-dose intravenous corticosteroids, the patient made a dramatic recovery and went on to have internal fixation of the shoulder and closure of the wound with a combination of a free flap and a rotational flap. Extensive myositis, as seen in this case, has not been previously reported in postoperative pyoderma gangrenosum variants. Clinicians should be aware that the presence of myositis and myonecrosis should not preclude this diagnosis.

Pyoderma gangrenosum masquerading as Donovanosis

Pyoderma gangrenosum (PG) is a rare inflammatory disorder of unknown etiology characterized by neutrophilic infiltration of the dermis and destruction of tissue. PG is diagnosed after excluding more commonly occurring condition presenting with similar manifestation. Though PG has been reported to occur over the genitalia, it rarely presents with concurrent involvement of the groin. Herein, we present a case of PG masquerading as Donovanosis.

Pyoderma gangrenosum: skin grafting and hyperbaric oxygen as adjuvants in the treatment of a deep and extensive ulcer

Pyoderma gangrenosum is a rare dermatosis of unknown etiology and variable clinical presentation. The disease is challenging for the medical staff, from the frequent diagnostic difficulties to the lack of scientific evidence with a good level to support the management of extensive and refractory cases. Our patient is a 50 year-old man with an extensive and deep ulcer on the left leg, which exemplifies the therapeutic difficulties inherent to the disease and who, fortunately, has progressed with excellent result after association of hyperbaric oxygen therapy and skin grafting to the immunosuppression therapy initially proposed.

Management of cicatricial ectropion secondary to pyoderma gangrenosum

Pyoderma gangrenosum is a rare condition with few cases of eyelid involvement reported in the literature. Pathergy is a well-recognised phenomenon that can trigger this condition. Pyoderma gangrenosum should be considered in cases of progressive cribriform cicatrisation where there is a history of antecedent trauma. Surgical management of a resultant ectropion may be challenging as a result of aggressive scarring and the risk of provoking a recurrence. We report a case of pyoderma gangrenosum causing a cicatricial ectropion, and discuss the underlying aetiology of iatrogenic incitement, and its implications for surgical management.

Autoinflammatory skin disorders in inflammatory bowel diseases, pyoderma gangrenosum and Sweet's syndrome: a comprehensive review and disease classification criteria

Pyoderma gangrenosum (PG) and Sweet's syndrome (SS) are skin diseases usually presenting with recurrent ulcers and erythematous plaques, respectively. The accumulation of neutrophils in the skin, characteristic of these conditions, led to coin the term of neutrophilic dermatoses to define them. Recently, neutrophilic dermatoses have been included in the group of autoinflammatory diseases, which classically comprises genetically determined forms due to mutations of genes regulating the innate immune response. Both PG and SS are frequently associated with inflammatory bowel diseases (IBDs); however, IBD patients develop PG in 1-3 % of cases, whereas SS is rarer. Clinically, PG presents with deep erythematous-to-violaceous painful ulcers with well-defined borders; bullous, pustular, and vegetative variants can also occur. SS is characterized by the abrupt onset of fever, peripheral neutrophilia, tender erythematous skin lesions, and a diffuse neutrophilic dermal infiltrate. It is also known as acute febrile neutrophilic dermatosis. Treatment of PG involves a combination of wound care, topical medications, antibiotics for secondary infections, and treatment of the underlying IBD. Topical therapies include corticosteroids and the calcineurin inhibitor tacrolimus. The most frequently used systemic medications are corticosteroids and cyclosporine, in monotherapy or in combination. Dapsone, azathioprine, cyclophosphamide, methotrexate, intravenous immunoglobulins, mycophenolate mofetil, and plasmapheresis are considered second-line agents. Hyperbaric oxygen, as supportive therapy, can be added. Anti-TNF-α agents such as etanercept, infliximab, and adalimumab are used in refractory cases. SS is usually responsive to oral corticosteroids, and the above-mentioned immunosuppressants should be considered in resistant or highly relapsing cases.

All that is red is not cellulitis. Pyoderma gangrenosum

A 60-year-old patient presented with progressive worsening, non-healing ulcer on her shin with surrounding erythema following a minor trauma and was treated with several antibiotics for presumed cellulitis with no improvement. A skin biopsy eventually suggested pyoderma gangrenosum and a colonic biopsy showed an underlying ulcerative colitis.

Pyoderma gangrenosum of the hand

Pyoderma gangrenosum is a rare, painful, ulcerative neutrophilic dermatosis that is not usually seen on the hands. Pyoderma gangrenosum is a diagnosis of exclusion, as there are no specific laboratory or histopathologic findings to confirm the diagnosis. Heightened awareness and early recognition are needed to decrease morbidity in these patients.

The F-BAR protein PSTPIP1 controls extracellular matrix degradation and filopodia formation in macrophages

PSTPIP1 is a cytoskeletal adaptor and F-BAR protein that has been implicated in autoinflammatory disease, most notably in the PAPA syndrome: pyogenic sterile arthritis, pyoderma gangrenosum, and acne. However, the mechanism by which PSTPIP1 regulates the actin cytoskeleton and contributes to disease pathogenesis remains elusive. Here, we show that endogenous PSTPIP1 negatively regulates macrophage podosome organization and matrix degradation. We identify a novel PSTPIP1-R405C mutation in a patient presenting with aggressive pyoderma gangrenosum. Identification of this mutation reveals that PSTPIP1 regulates the balance of podosomes and filopodia in macrophages. The PSTPIP1-R405C mutation is in the SRC homology 3 (SH3) domain and impairs Wiskott-Aldrich syndrome protein (WASP) binding, but it does not affect interaction with protein-tyrosine phosphatase (PTP)-PEST. Accordingly, WASP inhibition reverses the elevated F-actin content, filopodia formation, and matrix degradation induced by PSTPIP1-R405C. Our results uncover a novel role for PSTPIP1 and WASP in orchestrating different types of actin-based protrusions. Our findings implicate the cytoskeletal regulatory functions of PSTPIP1 in the pathogenesis of pyoderma gangrenosum and suggest that the cytoskeleton is a rational target for therapeutic intervention in autoinflammatory disease.

[The modern concepts of pyoderma gangrenosum]

The review provides an update on pyoderma ganrenosum, a rare chronic disease from a group of neutrophilic dermatoses. It considers its pathogenesis, its association with background visceral disease, and the specific features of skin and visceral involvement. Major and minor diagnostic criteria and differential treatment approaches are given.