title: Sex-specific manifestations of Löfgren's syndrome.
abstract: BACKGROUND
  It has been debated whether patients need to have erythema nodosum to be classified as having Löfgren's syndrome. In this study, we have therefore in detail evaluated and compared a large number of patients with an acute onset of sarcoidosis and bilateral hilar lymphadenopathy (BHL), with or without erythema nodosum (EN). This study is important because it may lead to a more accurate definition of Löfgren's syndrome, and an exact phenotype of patients is crucial in modern medical research.
  
  
  BACKGROUND
  Löfgren's syndrome is commonly regarded as a distinct clinical entity.
  
  
  METHODS
  We have in detail evaluated a large group of patients (n = 150) with an acute onset of sarcoidosis with BHL, in most cases with fever, EN, and/or bilateral ankle arthritis or periarticular inflammation. Within this group, 87 patients had EN (EN positive), whereas 63 were without EN (EN negative), though with distinct symmetric ankle inflammation.
  
  
  RESULTS
  EN-positive and EN-negative patients were identical in every aspect except that there were significantly more women in the EN-positive group: 58 women (67%) in the EN-positive group compared with only 17 (27%) women in the EN-negative group (p < 0.0001). In all other aspects, such as age, smoking habits, seasonal clustering of disease onset, rate of positive biopsies, chest radiography, pulmonary function, bronchoalveolar lavage cell distributions including the typically increased CD4/CD8 ratio, and clinical development of the disease, the EN-positive and EN-negative groups were close to identical. The two groups were also identically strongly associated with HLA-DRB1*0301/DQB1*0201, with 60 (69.0%) and 44 (69.8%) patients having this particular HLA type in the EN-positive and EN-negative groups, respectively. Such patients recovered to the same degree-that is, at almost 100%.
  
  
  CONCLUSIONS
  We conclude that manifestations of Löfgren's syndrome differ between men and women, with EN found predominantly in women, whereas a marked periarticular inflammation of the ankles or ankle arthritis without EN is seen preferentially in men.
authors.affiliation: Department of Medicine, Division of Respiratory Medicine, Karolinska Institutet Lung Research Laboratory L4:01, Karolinska University Hospital Solna, S-171 76 Stockholm, Sweden. johan.grunewald@ki.se
authors.forename: Johan
authors.initials: J
authors.lastname: Grunewald
authors.forename: Anders
authors.initials: A
authors.lastname: Eklund
mesh_terms: D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D016516:CD4-CD8 Ratio; D004893:Erythema Nodosum / Q000175:diagnosis* / Q000235:genetics; D005260:Female; D005787:Gene Frequency; D006683:HLA-DQ Antigens / Q000235:genetics*; D059866:HLA-DQ beta-Chains; D006684:HLA-DR Antigens / Q000235:genetics*; D059811:HLA-DRB1 Chains; D006801:Humans; D008206:Lymphatic Diseases / Q000175:diagnosis* / Q000235:genetics; D008297:Male; D013902:Radiography, Thoracic; D012129:Respiratory Function Tests; D017565:Sarcoidosis, Pulmonary / Q000175:diagnosis* / Q000235:genetics; D012737:Sex Factors; D013577:Syndrome
chemical_list: D006683:HLA-DQ Antigens; D059866:HLA-DQ beta-Chains; C069051:HLA-DQB1 antigen; D006684:HLA-DR Antigens; D059811:HLA-DRB1 Chains; C553502:HLA-DRB1*03:01 antigen