The causal relationship between inflammatory bowel diseases and erythema nodosum: a bidirectional two-sample mendelian randomization study.

BACKGROUND: Individuals with inflammatory bowel disease (IBD) exhibit a heightened likelihood of developing erythema nodosum (EN), but the presence of causal link is unknown. The purpose of the present research was to investigate this connection using a bidirectional two-sample Mendelian randomization (MR) analysis. METHODS: Summarized statistics for EN were sourced from the FinnGen consortium of European ancestry. The International Inflammatory Bowel Disease Genetic Consortium (IBDGC) was used to extract summary data for IBD. The inverse variance weighted (IVW) technique was the major method used to determine the causative link between them. RESULTS: The study evaluated the reciprocal causal link between IBD and EN. The IVW technique confirmed a positive causal link between IBD and EN (OR = 1.237, 95% CI: 1.109-1.37, p = 1.43 × 10- 8), as well as a strong causality connection between Crohn's disease (CD) and EN (OR = 1.248, 95% CI: 1.156-1.348, p = 1.00 × 10- 4). Nevertheless, a causal connection between ulcerative colitis (UC) and EN could not be established by the data. The reverse MR research findings indicated that analysis indicated that an increase in EN risks decreased the likelihood of UC (OR = 0.927, 95% CI: 0.861-0.997, p = 0.041), but the causal association of EN to IBD and CD could not be established. CONCLUSION: This investigation confirmed that IBD and CD had a causal connection with EN, whereas UC did not. In addition, EN may decrease the likelihood of UC. Further study must be performed to uncover the underlying pathophysiological mechanisms producing that connection.

Causal relationship between inflammatory bowel disease and erythema nodosum: A two-sample bidirectional Mendelian randomization study.

BACKGROUND: Previous studies have demonstrated the coexistence of erythema nodosum (EN) and inflammatory bowel disease (IBD), while the exact etiology of the co-occurrence of the two disorders remains uncertain. METHODS: A bidirectional two-sample Mendelian randomization (MR) design was employed to determine the causal link between EN and IBD. Genetic variations associated with Crohn's disease (CD) and ulcerative colitis (UC) were derived from accessible genome-wide association studies pertaining to European ancestry. The FinnGen database was used to find the genetic variations containing EN. In the forward model, IBD was identified as the exposure, whereas in the reverse model, EN was identified as the exposure. The causal link between IBD and EN was examined using a range of different analysis techniques, the primary one being the inverse variance weighted (IVW) method, including inverse variance weighted-fixed effects (IVW-FE) and inverse-variance weighted-multiplicative random effects (IVW-MRE). To strengthen the results, assessments of sensitivity, heterogeneity, and pleiotropy were also conducted. RESULTS: MR results showed that IBD increased the risk of EN (IVW-MRE: OR = 1.242, 95% CI = 1.068-1.443, p = 0.005). Furthermore, there was a strong correlation found between CD and a higher risk of EN (IVW-FE: OR = 1.250, 95% CI = 1.119-1.396, p = 8.036 × 10-5 ). However, UC did not appear to be linked to EN (IVW-FE: OR = 1.104, 95% CI = 0.868-1.405, p = 0.421). The reverse MR analysis findings did not imply that EN was linked to IBD. Horizontal pleiotropy did not appear to exist, and the robustness of these findings was confirmed. CONCLUSION: The current investigation found that in European populations, IBD and its subtype CD could raise the incidence of EN.

Erythema nodosum in children: a cohort study from a tertiary pediatric hospital in Italy.

Erythema nodosum (EN), although relatively uncommon in the pediatric population, is the most frequent type of panniculitis in children. The present study aimed to report all the cases of children admitted to our tertiary pediatric hospital with the diagnosis of EN to evaluate the epidemiology, clinical manifestations, etiology, treatment, and the course of this disease in the pediatric age. This observational study retrospectively considered all children evaluated to the emergency room (ER) of Meyer Children's University Hospital, Florence, Italy, discharged with a diagnosis of EN over a 12-year period (from January 2009 to December 2021). Clinical and laboratory data were recorded using a standardized report form. Sixty-eight patients with EN were included. The etiologic diagnosis of EN was made in 38 children (55.9%): 29 (42.6%) had infection-related EN (in particular EBV and ß-hemolytic streptococcus), 6 (8.8%) had Crohn's disease, 1 celiac disease, 1 Sjogren syndrome, and 1 Hodgkin lymphoma. In 30 patients (45%), no definitive diagnosis was reached, and they were defined as having idiopathic EN. Most of the laboratory tests were nonspecific. No statistical differences were found in the demographic and clinical data, and the main diagnostic laboratory parameters between patients with idiopathic EN versus those with secondary EN.  Conclusion: Since EN can be isolated or the first manifestation of heterogeneous underlying pathologies, some of which can be severe and life-threatening, it is important to recognize it and carry out all the necessary etiological diagnostic investigations to understand its etiology and start the specific treatment. What is Known: • Erythema nodosum (EN) is the most frequent type of panniculitis in children. • It has been associated with a wide spectrum of disorders, such as different types of infection, malignancies, chronic inflammations, and drugs. What is New: • No statistical differences can be found in clinical features as well as laboratory data, between patients with idiopathic EN versus those with secondary EN. • A broad spectrum of investigations and a proper follow-up should be taken into account in order to prevent a delayed or missed secondary EN diagnosis.

Characterization and prevalence of extraintestinal manifestations in a cohort of patients with inflammatory intestinal disease in Medellin, Colombia. / Caracterización y prevalencia de manifestaciones extraintestinales en una cohorte de pacientes con enfermedad inflamatoria intestinal en Medellín (Colombia).

INTRODUCTION: Extraintestinal manifestations (EIMs) are frequent in patients with inflammatory bowel disease (IBD). Our objective is to characterize and determine the prevalence of MEIs in our cohort of patients with IBD. PATIENTS AND METHODS: A retrospective study was carried out in adult patients with IBD at the Pablo Tobón Uribe Hospital in Medellín. Colombia. Articular MEIs, primary sclerosing cholangitis (PSC), both ophthalmological and dermatological, were considered. Absolute and relative frequencies were used. The Chi square test of independence was used to compare 2proportions and the odds ratio (OR) was estimated. RESULTS: Our registry has 759 patients with IBD, 544 present UC (71.6%), 200 CD (26.3%) and 15 unclassifiable IBD (1.9%); 177 patients with IBD (23.3%) presented EIMs, 123 of 544 (22.6%) with UC and 53 of 200 (26.5%) with CD (OR: 0.81, 95% CI: 0.55-1.17, P=0.31). Regarding the type of EIMs, the articular ones were the most frequent (13.5%), more in CD than in UC (20.0 vs. 11.3%, OR 1.94, 95% CI: 1.25-3.00, P=0.0037). Patients with IBD and EIMs used more antibodies against tumor necrosis factor (anti-TNFs), compared to those without EIMs (43.5 vs. 18.5%, OR 3.38, 95% CI: 2.31-4.90, P=0.0001). CONCLUSIONS: The prevalence of EIMs in our cohort is high (23.3%) and the most frequent type is joint. Anti-TNFs are most used when IBD and EIMs coexist. Our study provides valuable information on the association of EIMs and IBD in Latin America.

Chronic nonbacterial osteomyelitis in children: a multicenter case series.

Chronic nonbacterial osteomyelitis (CNO) is a primary autoinflammatory bone disease that presents more frequently in children and is characterized by inflammatory bone lesions in the absence of an infectious etiology. There is little information of this disease in Latin America. The objective of the study was to evaluate demographic, clinical, laboratory, imaging, histopathology characteristics, and treatment responses of pediatric CNO patients. The clinical records of 19 patients with CNO diagnosed between 2007 and 2019 at three tertiary centers in Santiago, Chile were reviewed. The median age of onset was 10 years and 47% were female. Median delay in diagnosis was 12 months. All patients had a pattern of recurrent multifocal disease. 37% of patients had positive antinuclear antibodies and 16% HLA-B27 positivity. 21% of patients presented arthritis or other rheumatologic comorbidity, although no association with psoriasis, inflammatory bowel disease (IBD) or palmoplantar pustulosis (PPP) was observed. Eighteen patients received treatment with nonsteroidal anti-inflammatory drugs with partial response. Twelve patients received methotrexate, and half of them received steroids at the same time reaching remission in 50%. Of the five patients who received bisphosphonates, 60% achieved remission. All four patients who received adalimumab had comorbid arthritis and 75% achieved remission. In a series of Chilean children with CNO, all patients presented with multifocal lesions. Comorbid autoimmune diseases including arthritis were frequent, but no association was observed with psoriasis, IBD, or PPP.

Clinical, Epidemiological, and Etiological Changes in Erythema Nodosum.

BACKGROUND: Erythema nodosum (EN) is the most common type of panniculitis, commonly secondary to infectious diseases. OBJECTIVES: To elucidate the causative factors and the clinical presentation of patients with EN (2004-2014) and to compare their data to those reported in a previous study. METHODS: A retrospective study was conducted of all patients diagnosed with EN who were hospitalized at Soroka University Medical Center (2004-2014). The clinical, demographic, and laboratory characteristics of the patients were compared to those in a cohort of patients diagnosed with EN from 1973-1982. RESULTS: The study comprised 45 patients with a diagnosis of EN. The most common symptoms of patients hospitalized with EN were arthritis or arthralgia (27% of patients). Patients with EN, compared to those reported in 1987, has significantly lower rates of fever (18% vs. 62% P < 0.001), streptococcal infection (16% vs. 44%, P = 0.003), and joint involvement (27% vs. 66%, P < 0.001). In addition, fewer patients had idiopathic causes of EN (9% vs. 32%, P = 0.006). CONCLUSIONS: In the past decades, clinical, epidemiological, and etiological changes have occurred in EN patients. The lowering in rate of fever, streptococcal infection, and joint involvement in patients with EN are probably explained by improvements in socioeconomic conditions. The significantly decreasing rate of idiopathic causes of EN is possibly due to the greater diagnostic accuracy of modern medicine. The results of the present study demonstrate the impact of improvements in socioeconomic conditions and access to healthcare on disease presentation.

Leprosy reactions in postelimination stage: the Bangladesh experience.

BACKGROUND: Leprosy reactions are immunologically mediated conditions and a major cause of disability before, during and after multidrug therapy (MDT). Little data have been published on the epidemiology of leprosy reactions in Bangladesh. OBJECTIVES: To describe the pattern and prevalence of leprosy reactions in the postelimination stage. METHODS: A descriptive retrospective cross-sectional study was carried out in Chittagong Medical College Hospital using the registered records of patients in the period between 2004 and 2013. RESULTS: Of the 670 patients with leprosy, 488 (73.38%) were males and 182 (27.37%) were females. The prevalence of reaction was in 300 (44.78%) patients with a male:female ratio of 3.55 : 1. The age-specific cumulative reaction cases at >40 years were 115 (38.33%) among all age groups. The prevalence of reaction was found to be in 166 (55.33%) patients for the reversal reaction, 49 (16.57%) for the erythema nodosum leprosum (ENL) and 85 (28.33%) for the neuritis. Borderline tuberculoid was most common (106, 35.33%)in the reversal reaction group, while lepromatous leprosy was most common (37, 12.33%) in ENL group. More than half of the patients (169, 56.33%) had reactions at the time of presentations, while 85 (28.33%) and 46 (15.33%) patients developed reaction during and after MDT, respectively. The reversal reaction group presented with ≥six skin lesions in 96 (57.83%) patients and ≥two nerve function impairments (NFIs) in 107 (64.46%) patients. The ENL was present chiefly as papulo-nodular lesions in 45 (91.84%) patients followed by pustule-necrotic lesions in four (8.16%), neuritis in 33 (67.35%), fever in 24 (48.98%), lymphadenitis in six (12.24%), arthritis in five (10.20%) and iritis in two (4.08%). Bacterial index ≥3 had been demonstrated in 34 (60.71%) patients in ENL group. CONCLUSION: The incidence of leprosy reaction seemed to be more than three times common in borderline tuberculoid (52.33%) group than in lepromatous leprosy (14%) group. Reactions with NFI and disability still occur among multibacillary patients during and after MDT. Early detection and management of leprosy reaction are very important in preventing disability and deformity, and patients should be educated to undergo regular follow-up examinations. Developing reinforced new therapies to curb leprosy reactions is crucial for improving leprosy healthcare services.

Extra-Gastrointestinal Manifestations of Inflammatory Bowel Disease May Be Less Common Than Previously Reported.

BACKGROUND AND AIMS: Extra-intestinal manifestations are well recognized in inflammatory bowel disease (IBD). To what extent the commonly recognized extra-intestinal manifestations seen in IBD patients are attributable to IBD is, however, not clear due to the limited number of controlled studies published. METHODS: We have conducted a study of these manifestations using electronic primary care records. We have identified extra-intestinal manifestations in IBD and non-IBD patients and derived odds ratios (ORs) using conditional logistic regression. RESULTS: A total of 56,097 IBD patients (32.5 % Crohn's disease, 48.3 % ulcerative colitis (UC) and 19.2 % not classified) were matched to 280,382 non-IBD controls. We found records of pyoderma gangrenosum (OR = 29.24), erythema nodosum (OR = 5.95), primary sclerosing cholangitis (OR = 188.25), uveitis (OR = 2.81), ankylosing spondylitis (OR = 7.07), sacroiliitis (OR = 2.79) and non-rheumatoid inflammatory arthritides (OR = 2.66) to be associated with IBD. One or more of these was recorded in 8.1 % of IBD patients and 2.3 % of controls. Non-specific arthritides were present in many more patients, affecting 30 % of IBD patients and 23.8 % of controls overall. We also found weaker associations with a number of conditions not generally considered to be extra-intestinal manifestations including psoriasis, ischemic heart disease, multiple sclerosis and hay fever. CONCLUSION: Although "classical" extra-intestinal manifestations are strongly associated with IBD, most IBD patients remain unaffected. Arthropathies, perceived to be the commonest extra-intestinal manifestation, are not strongly associated with IBD, and the proportion of arthropathies attributable to IBD is likely to be small.

[Clinical analysis of cutaneous manifestations and related factors in patients with ulcerative colitis].

OBJECTIVE: To investigate the cutaneous manifestations in patients with ulcerative colitis (UC) and related factors. METHODS: Patients admitted to Department of Gastroenterology Peking University First Hospital from January 1994 to December 2014 and diagnosed as UC were retrospectively enrolled in this study. Skin disorders were confirmed by the dermatologists. Clinical data were collected and compared between patients with and without cutaneous manifestations. RESULTS: Among the total 373 UC patients, there were 34 cases (9.1%) with cutaneous manifestations, including 11 pyoderma gangrenosum, 8 erythema nodosum, 6 eczema, 3 psoriasis, 2 pemphigus, 1 granulomatous cheilitis, 1 ichthyosis, 1 acne rosacea, and 1 impetigo. The skin manifestations may occur after the diagnosis, simultaneously or even before the diagnosis of UC, which were 24, 7 and 3 patients respectively. The mean age in patients with skin lesions was (47.2±12.1) years, male to female ratio 0.79∶1. More patients with skin manifestations had severe activity of UC compared with non-skin group [50.0%(17/34) vs 25.1%(85/339), P=0.01]. In addition, the proportion of extensive colitis in skin lesion group was significantly higher than that in non-skin group [76.5%(26/34) vs 54.6%(185/339), P=0.04]. CONCLUSIONS: The cutaneous manifestations associated with UC are polymorphic, erythema nodosums and pyoderma gangrenosums are the most common skin lesions seen in UC patients. Skin lesions occur concurrently, pre or post the diagnosis of UC. Skin lesions in UC patients suggest more severe disease activity. Clinicians need to pay more attention to this group.

Predictive factors for erythema nodosum and pyoderma gangrenosum in inflammatory bowel disease.

BACKGROUND AND AIM: To identify predictive factors related to the development of erythema nodosum and pyoderma gangrenosum, in patients with inflammatory bowel disease (IBD). METHODS: Epidemiological and clinical data from 270 patients with Crohn's disease (CD) and 125 patients with ulcerative colitis (UC) were collected between 2003 and 2011. The variables retrospectively analyzed were: gender, age at diagnosis, type of IBD (CD or UC), smoking habit, pattern of disease (IBD), location and extension, family history, previous IBD-related surgery, other extraintestinal manifestations (EIMs), and previous biological and immunosuppressive therapy. RESULTS: Thirty-seven patients showed at least one cutaneous manifestation. These lesions were more frequent in women (15.4%) than in men (4.2%; P = 0.0001) and in CD (12.2%) than in UC patients (3.2%; P = 0.005). These manifestations were more frequently associated with other EIMs (25% vs 7.2%; P = 0.0001), and they were less frequent in patients who received a previous biological therapy for IBD (6.8% vs 11.2%; P = 0.1). Patients with skin manifestations were younger at diagnosis of IBD than those patients without them (26.3 ± 10 vs 32.9 ± 14.5, P = 0.008). Independent variables significantly associated with development of skin manifestations were: female (P = 0.008), previous biological therapy (P = 0.007), age at diagnosis (young, P = 0.026), type of IBD (CD, P = 0.043) and presence of other EIMs (P = 0.0001). CONCLUSION: Predictive factors involved in the development of main cutaneous manifestations are: female, CD, young age at diagnosis of IBD, and presence of other EIMs. Early use of biological therapies prevents the development of cutaneous manifestations.

Examining ERBB2 as a candidate gene for susceptibility to leprosy (Hansen's disease) in Brazil.

Leprosy remains prevalent in Brazil. ErbB2 is a receptor for leprosy bacilli entering Schwann cells, which mediates Mycobacterium leprae-induced demyelination and the ERBB2 gene lies within a leprosy susceptibility locus on chromosome 17q11-q21. To determine whether polymorphisms at the ERBB2 locus contribute to this linkage peak, three haplotype tagging single nucleotide polymorphisms (tag-SNPs) (rs2517956, rs2952156, rs1058808) were genotyped in 72 families (208 cases; 372 individuals) from the state of Pará (PA). All three tag-SNPs were associated with leprosy per se [best SNP rs2517959 odds ratio (OR) = 2.22; 95% confidence interval (CI) 1.37-3.59; p = 0.001]. Lepromatous (LL) (OR = 3.25; 95% CI 1.37-7.70; p = 0.007) and tuberculoid (TT) (OR = 1.79; 95% CI 1.04-3.05; p = 0.034) leprosy both contributed to the association, which is consistent with the previous linkage to chromosome 17q11-q21 in the population from PA and supports the functional role of ErbB2 in disease pathogenesis. To attempt to replicate these findings, six SNPs (rs2517955, rs2517956, rs1810132, rs2952156, rs1801200, rs1058808) were genotyped in a population-based sample of 570 leprosy cases and 370 controls from the state of Rio Grande do Norte (RN) and the results were analysed using logistic regression analysis. However, none of the associations were replicated in the RN sample, whether analysed for leprosy per se, LL leprosy, TT leprosy, erythema nodosum leprosum or reversal reaction conditions. The role of polymorphisms at ERBB2 in controlling susceptibility to leprosy in Brazil therefore remains unclear.

Erythema nodosum in northern Finland between 1996 and 2019: A register-based study.

Erythema nodosum (EN) is seen at any age with varying and often unidentified etiology. We studied the etiology and characteristics of EN in Northern Finland. Medical records of all patients with a diagnosis code for EN between 1996 and 2019 from Oulu University Hospital were retrieved and analyzed. There were in total 142 EN cases with a female predominance (n = 112, 72.9%). The mean age of the patients was 35.9 years. There were five cases diagnosed with EN in those younger than 2 years of age. Almost one third had EN nodules in multiple anatomical locations. In addition to skin findings, systemic symptoms were common (81.0%), and seen more often in men (p < 0.05). In children and adolescents, the most common etiological factors were gastroenteritis caused by 'Yersinia, Salmonella or Campylobacter', followed by inflammatory bowel diseases and hormonal contraception. Bacterial infections were the most common etiological factor among adults. In 28.2% of the cases there was no identified causative factor. In this study, EN was seen surprisingly often in small children. Etiological factors varied markedly among different age groups and symptoms differed between the sexes in adults. These aspects should be taken into account when diagnosing EN patients.

Toxoplasma gondii infection and high levels of IgE are associated to erythema nodosum leprosy (ENL).

Leprosy is a chronic infectious disease caused by the bacillus Mycobacterium leprae. The disease may evolve for inflammatory reactions, reversal reaction (RR) and erythema nodosum leprosum (ENL), the major cause of irreversible neuropathy in leprosy, which occur in 1 in 3 people with leprosy, even with effective treatment of M. leprae. Leprosy remains persistently endemic in our region where it predominantly affects lowest socioeconomic conditions people, as Toxoplasma gondii infection in the municipality studied. Previously, we have shown T. gondii coinfection as a risk marker for leprosy, mainly in its severe form. This present study assessed whether T. gondii infection is also a risk factor for leprosy reactions and the predictive value of immunoglobulin production prior to development of leprosy reactions. Patients with leprosy (n = 180), co-infected or not with T. gondii, had their serum investigated for levels of IgA, IgE, IgG1, IgG2, IgG3 and IgG4 anti-PGL-1 by ELISA prior to development of leprosy reactions. The serologic prevalence for T. gondii infection was 87.7% in leprosy reaction patients reaching 90.9% in those with ENL. The leprosy reaction risk increased in T. gondii seropositive individuals was two-fold ([OR] = 2.366; 95% confidence interval [CI 95%]: 1.024-5.469) higher than those seronegative, and considering the risk of ENL, this increase was even more evident (OR = 6.753; 95% CI: 1.050-72.85) in coinfected individuals. When evaluated the prediction of anti-PGL-1 immunoglobulin levels for development of leprosy reactions in patients coinfected or not with T. gondii, only the increase IgE levels were associated to occurrence of reactional episodes of leprosy, specifically ENL type, in patients coinfected with T. gondii, compared to those not coinfected or no reaction. Thus, the immunomodulation in co-parasitism T. gondii-M. leprae suggest increased levels of IgE as a biomarker for early detection of these acute inflammatory episodes and thereby help prevent permanent neuropathy and disability in leprosy patients.

How to make a specific diagnosis of panniculitis on clinical grounds alone: an integrated pathway of general criteria and specific findings.

A clinical approach to the vexing problem of diagnosis of panniculitis is traced in this paper, in order to obtain from the clinical findings, history and laboratory data of the patient useful, detailed and precise information, essential to address dermatologists to a specific clinical diagnosis of panniculitis. This approach is created in the same way as when a dermatologist faces any other dermatological disease, be it inflammatory or neoplastic. A common behavior in case of panniculitis is in fact just to take an adequate biopsy and wait for the pathologist report. This is indeed a limitation both for the dermatologist and above all for the pathologist, who is in tremendous need for detailed clinical information before signing his report. The most common types of panniculitides, taking into account their main clinical diagnostic criteria, will be considered. In particular, Erythema Nodosum, Panniculitides in Sarcoidosis, Pancreatic Panniculitis, Lupus Panniculitis, Erythema Induratum/Nodular Vasculitis and Weber-Christian Panniculitis/Rothman-Makai Pannicultis will be analyzed. Every chapter will consider general criteria (epidemiology, age and gender, distribution of the lesions, laboratory findings) and specific findings (characteristics of the lesions, i.e. redness, pain, tenderness, evolution, ulceration, sites of involvement) as well as comorbidities and systemic signs and symptoms. Detailed analysis of the general criteria integrated with the specific findings will allow the clinicians to reach a clinical diagnosis with a high degree of confidence.

Erythema nodosum.

Erythema nodosum is an acute inflammatory dermatosis characterized by painful nodules which are generally symmetrical and non ulcerative and are mainly located to the extensor surface of the lower legs. The nodules, due to septal panniculitis, are often accompanied by fever and resolve without permanent sequelae. Arthralgia occurs in more than 50% of patients and begins during the eruptive phase or precedes the eruption by 2-4 weeks. Erythema nodosum is presumed to be a hypersensitivity reaction and may occur in association with several systemic diseases or drug therapies, or it may be idiopathic. The most common cause of erythema nodosum is streptococcal infection in children and streptococcal infection and sarcoidosis in adults. Peak incidence occurs at age 18-34 years. Age and sex distributions vary according to etiology and race; women are affected more often than men. It is possible to distinguish between an acute and a chronic form of erythema nodosum; in the acute form, an early stage and a late stage can be detected, both clinically and histologically. Laboratory and instrumental examinations to be performed in case of erythema nodosum are varied and are intended to identify any underlying trigger disease. Erythema nodosum is a self-limited disease, so the therapy is often only symptomatic. Even if the erythema nodosum quickly responds to systemic steroids, in most cases their use is not recommended, nor necessary; is usually sufficient to use NSAIDs (eg, acetyl salicylic acid, ibuprofen, naproxen, indomethacin).

Psoriasis and erythema nodosum: two comorbidities of inflammatory bowel diseases.

Extra-intestinal manifestations are a relatively common complications of Inflammatory Bowel Diseases (IBD) and skin is one of the organs most commonly affected. Cutaneous findings in IBD patients may be related to different pathogenetic mechanisms and in some cases the etiologic link has not been fully elucidated. In particular, this is the case of psoriasis and erythema nodosum, two of the most frequent skin diseases observed in IBD patients. Aim of this paper was to review the epidemiology and the possible pathogenetic mechanisms implicated in the occurrence of these two dermatosis. In particular, an association between IBD and psoriasis has been observed in several epidemiological studies: psoriasis occurs in about 1-2% of the general population, compared with 3-11% of patients with IBD. Several studies have also evaluated the prevalence of IBD in psoriatic patients, with contrasting results. A common pathogenic pathways between these two conditions seems to be sustained by the responsiveness to therapy with biological treatments, such as anti-Tumor Necrosis Factor (TNF)-alpha agents and ustekinumab (a monoclonal antibody against p40 subunit common to IL-12 and IL-23). On the other hand, although usually idiopathic in half of the patients, erythema nodosum has been associated with a variety of disorders and conditions and IBD accounts for 1-4% of cases.

Panniculitis in children.

This paper will give a comprehensive view of the most frequent panniculitides seen in childhood, with emphasis on the types exclusively found in infancy, and for all other types of panniculitides also found in adults. Aim of this paper is also to analyze the clinical differences between panniculitis in childhood and in adulthood, and to give reliable histopathologic criteria for a specific diagnosis. A review of the literature is here integrated by authors' personal contribution. Panniculitides in children is a heterogeneous group of diseases, as well as in adult life, characterized by inflammation of the subcutaneous fat. Only very few types of panniculitis are exclusively found in childhood, such as Sclerema neonatorum and subcutaneous fat necrosis of the newborn, while the vast majority of the other types may be found both in paediatric age and in adults. Furthermore, this paper will consider in detail panniculitis according to their frequency, such as Erythema nodosum, Lupus panniculitis, Cold panniculitis, panniculitis in Behçet disease, and poststeroid panniculitis. It will also describe rare forms of panniculitis, such as Eosinophilic panniculitis (a pathological entity debated by many authors), Subcutaneous panniculitis T-cell lymphoma, and the different forms of the so call "Lipophagic panniculitis", encompassing respectively the febrile relapsing panniculitis of Weber-Christian disease and the non-relapsing form of Rothmann-Makai disease. For each type of panniculitis considered concise information will be given about epidemiology, etiology, clinical findings, laboratory data, prognosis and therapy, while histopathologic findings will be described in detail.