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Concept: Erythema nodosum


BACKGROUND: Sarcoidosis is a systemic disease characterized by the formation of noncaseating granulomas in various tissues. Cutaneous involvement occurs in 20 to 35 percent of the patients and may be the initial manifestation of the disease. Our study was performed to discriminate the clinical, laboratory, and prognostic differences between patients with specific and nonspecific cutaneous involvement. The second aim was to asses the diagnostic usefulness of punch biopsy in sarcoidosis. METHODS: The clinical, laboratory, pathological features, and skin biopsy results of 120 patients with cutaneous sarcoidosis were evaluated. The patients fulfilled clinical, radiologic or both features of sarcoidosis supported by the histopathologic evidence of noncaseating granulomas.Skin involvement was the initial finding in 30% of the patients. Erythema nodosum and lupus pernio were the most common skin lesions. Almost all of the patients with LP were either stage 0 or 1. Respiratory symptoms occurred in 72.2% of the patients with specific skin involvement. BronchoalveolarLavage (BAL) lymphocytosis, high ratio of CD4/CD8 and elevated serum Angiotensin Converting Enzyme (ACE) were more frequent in patients with specific cutaneous lesions. The frequency of progressive disease was significantly higher in this group. Punch skin biopsy was diagnostic in 81.6% of the patients with a complication rate of 4%. CONCLUSIONS: Specific cutaneous lesions along with BAL lymphocytosis, high CD4/CD8 ratio and elevated serum ACE levels may be predictors of progressive disease in sarcoidosis. Punch biopsy is a simple technique with a high diagnostic yield and a low complication rate for cutaneous sarcoidosis.

Concepts: Medical terms, Biopsy, Pathology, Sarcoidosis, Granuloma, Skin biopsy, Erythema nodosum, Lupus pernio


Mycobacterium tuberculosis (MTB) infection has been suggested to contribute to the pathogenesis of erythema nodosum (EN) and nodular vasculitis (NV), the classic forms of panniculitis. However, there is little evidence to demonstrate the presence of MTB in the skin lesions. This study is aimed at evaluating the association between MTB infection and the development of EN and NV in a Chinese population.

Concepts: Tuberculosis, The Association, Mycobacterium, Mycobacterium tuberculosis, Sarcoidosis, Erythema nodosum, Behçet's disease, Conditions of the subcutaneous fat


Background  “Tender cutaneous nodules of the legs” is a common manifestation in dermatology. Histopathological investigation is usually required for this condition, because clinical data are frequently insufficient to make a definite diagnosis. Objective  To identify and analyze the causes of patients presenting with tender leg nodules and to reveal clinical clues that could help to differentiate causes. Materials and methods  The medical records and histopathological slides of patients presenting with tender cutaneous nodules of the legs between January 2005 and December 2007 were retrospectively reviewed. Results  Of the total of 154 patients, 122 (79.2%) were female. Definite diagnoses were categorized into four groups: inflammation (84.4%); infection (5.8%); tumor (6.5%); and nonspecific (3.2%). The most common cause in the inflammation group was erythema nodosum. The infections found were Acremonium spp., Penicillium sp., Mycobacterium abscessus, Mycobacterium fortuitum and Mycobacterium leprae. The tumors included leiomyoma, leukemia cutis, and lymphomas. Clinical data that correlated with and could be used as clues for the inflammation group were female sex (P = 0.03, OR 6.43) and lower leg involvement (P = 0.03, OR 7.14). Limitations  The retrospective manner of this study is a limitation. Conclusion  Various inflammatory conditions, infections, and tumors can present as tender cutaneous nodules of the legs. Female sex and lower leg involvement were clinical data that could be used as clues for the diagnoses in the inflammation group. However, histopathological investigation is still crucial to determine a definite diagnosis in patients presenting with tender cutaneous nodules of the legs.

Concepts: Inflammation, Cancer, Infection, Mycobacterium, Human leg, Leprosy, Erythema nodosum, Mycobacterium leprae


Erythema nodosum (EN) is the most common cause of inflammatory nodules and usually affects the lower extremities and especially pretibial regions. EN may be idiopathic or associated with a wide spectrum of conditions including systemic diseases, infection, treatment with various drugs, pregnancy, and exceptionally with malignancies. The purpose of this study is to investigate the EN patients with different etiologies and laboratory features admitted to the rheumatology department and to compare them with other EN patients admitted to different departments including dermatology and infectious diseases. Totally, 107 patients diagnosed with EN (male/female: 37/70) were enrolled in the study. Of the 107 EN patients, 37 participants who were categorized as primary (idiopathic) EN (34.6 %) had not any underlying diseases or precipitating events. Majority of the participants were women (male/female: 12/25; mean age: 42.9 ± 9.2 years). Precisely, 70 EN (secondary EN) patients (65.4 %) had an underlying disease (male/female: 25/45; mean age: 36.1 ± 10.1). Behçet’s disease (BD) was the foremost (n = 40, 37.4 %), followed by sarcoidosis (n = 17, 15.9 %), post-streptococcal (n = 9, 8.4 %), and other rheumatologic disease (one patient temporal arthritis, one patient Sjögren’s syndrome, 1.9 %). Consequently, it is observed that BD, sarcoidosis, and post-streptococcal infection were found as the main etiologies of EN patients treated in our rheumatology department. These diseases should be kept in mind as an etiological factor in the management of EN.

Concepts: Medicine, Cancer, Disease, Infectious disease, Hospital, Infection, The Canon of Medicine, Erythema nodosum


Staphylococcus xylosus is a coagulase-negative staphylococcus. It is a commensal bacterium associated with skin and mucous membranes and occasionally it can cause human infections. We report the first case of erythema nodosum developed in a young woman with S. xylosus septicemia and specific serum antibody response.

Concepts: Antibody, Bacteria, Staphylococcus aureus, Staphylococcus, Gram positive bacteria, Staphylococcaceae, Erythema nodosum, Staphylococcus xylosus


Erythema nodosum (EN) is the most common form of panniculitis. It is characterized by erythematous, raised, tender nodules that usually occur bilaterally on the extensor surfaces of the lower extremities. EN is associated with many underlying conditions including infection, sarcoidosis, malignancy, and pregnancy. Its underlying etiology, however, is unknown in up to half of cases. Pregnancy is thought to create an optimal background for EN to develop, although the exact mechanisms are unclear. Immune complexes may play a role in the pathogenesis of EN during pregnancy, or EN may be a hypersensitivity reaction to either estrogens or progesterone. EN is a self-limiting process, and non-pharmacologic means such as bed rest and elastic web bandages may be sufficient to control the symptoms. Potassium iodide, systemic and intralesional corticosteroids, non-steroidal anti-inflammatory drugs, salicylates, tumor necrosis factor-α inhibitors, hydroxychloroquine, colchicine, and dapsone are other treatment options available, but some of these drugs are contraindicated in pregnancy while others are considered safe. Before prescribing one of these treatments to a pregnant patient, the patient’s obstetrician should be consulted, and a careful risk-benefit analysis should be performed.

Concepts: Immune system, Pregnancy, Hypersensitivity, Non-steroidal anti-inflammatory drug, Progesterone, Sarcoidosis, Erythema nodosum, Potassium iodide


Takayasu’s arteritis is a rare, systemic vasculitis with varied presentations across multiple medical specialities. Here, we present a young woman who had recurrent episodes of erythema nodosum on the background of a low-grade fever and no vascular manifestations. The presence of a high erythrocyte sedimentation rate generated a high index of suspicion for underlying vasculitis, and radioimaging confirmed the suspicion of Takayasu’s arteritis. The patient was found to have type III diseases in the vasculitic stage and was managed with systemic corticosteroids.

Concepts: Cardiology, Rheumatoid arthritis, Vasculitis, Hematology, Hodgkin's lymphoma, Sarcoidosis, Takayasu's arteritis, Erythema nodosum


Lsr 2 protein of Mycobacterium leprae (ML) and its synthetic peptides were shown earlier to elicit lymphoproliferation and interferon γ (IFN γ) release by peripheral blood mononuclear cells (PBMC) of lepromatous leprosy patients (1). PBMC from 16 lepromatous patients undergoing erythema nodosum leprosum (ENL, Type 2) and 5 with reversal reactions (RR, Type 1) were stimulated with ML, recombinant Lsr 2 and six end to end synthetic peptides ( A-F) spanning the Lsr 2 sequence. During reaction all ENL patients showed lymphoproliferation (> 2 stimulation index) to peptides A and F with other peptides eliciting responses in 75-88% of the subjects. Both lymphoproliferation and IFN γ release for peptide E was significantly higher compared to peptides, B,C and recombinant Lsr 2 (p< 0.05, Wilcoxon signed rank test) in PBMC cultures. Five RR patients also showed enhanced lymphoproliferative responses and IFN γ release to Lsr 2, ML and peptide E. Six months post reaction, 14 ENL patients continued to exhibit responses to Lsr 2 and its peptides with the highest responses being elicited by peptide E. However, 5 subjects showed no lymphoproliferation and reduced IFN γ release to Lsr 2 peptides (p< 0.001, Kruskal Wallis test) but responded to recombinant Lsr 2. Six ENL patients had HLA A*68.01 which showed high peptide binding scores of 20-21 for peptides E, B, C using STFPEITHI program. Eleven patients had HLA-DRB1*1501 and *1502 which had high binding scores for peptides C and E. Thus, Lsr 2 and its peptides are recognized in leprosy reactions during and well after subsidence of clinical signs.

Concepts: Protein, Peptide, Mycobacterium, PBMC, Wilcoxon signed-rank test, Leprosy, Erythema nodosum, Mycobacterium leprae


A 68-year-old man who had Behçet’s disease with a 30-year history of oral and genital ulcers and erythema nodosum presented with progressive leg edema and dyspnea. The physical examination revealed varices of the chest and abdominal wall.

Concepts: Physical examination, Erythema nodosum


Erythema Nodosum Leprosum (ENL) is a humoral immunological response in leprosy that leads to inflammatory skin nodules which may result in nerve and organ damage, and may occur years after antibiotic treatment. Multiple episodes are frequent and suppression requires high doses of immunosuppressive drugs. Global occurrence is unknown.

Concepts: Immune system, Antibody, Medicine, Immunology, Humoral immunity, Immunity, Immunosuppressive drug, Erythema nodosum