necrotising fasciitis ( nf ) is a serious soft tissue and life threatening infection , primarily involving the skin and superficial fascia , characterised by a rapid and extensive necrosis of the subcutaneous tissue .
most patients have associated comorbidities , such as diabetes , hiv infection or treatment with immunosuppressive drugs , but it can also affect previously healthy individuals .
infection is one of the common causes of morbidity and mortality in patients with systemic lupus erythematosus ( sle ) .
it is associated with immunosuppressive agents , renal failure , and increased disease activity . despite the increased propensity of sle patients to develop common and opportunistic infections , nf has rarely been reported . to our knowledge
, only 31 cases are described in the literature to date ( see table 1 ) .
nf has also been described in other rheumatic diseases including polymyositis , dermatomyositis , systemic sclerosis , rheumatoid arthritis and ankylosing spondylitis , but it appears that this association is more common in sle.1 
 2 clinical features of nf in systemic lupus erythematosus a , asian ; aa , african  american ; aps , antiphospholipid syndrome ; art , arthritis ; avn , avascular necrosis ; aza , azathioprine ; cad , coronary artery disease ; cs , corticosteroid therapy ; cyc , cyclophosphamide ; d , died ; dm , diabetes mellitus ; f , female ; fg , fournier 's gangrene ; h , hispanic ; hcq , hydroxychloroquine ; lym , lymphocytes ; m , male ; mmf , mycophenolate ; mtx , methotrexate ; n , nephritis ; na , not available ; nf , necrotising fasciitis ; pe , pulmonary embolism ; rtx , rituximab ; s , survived ; sa , staphylococcus aureus ; ttp , thrombotic thrombocytopenic purpura ; wbc , white blood cells .
we describe the case of a nf caused by pseudomonas aeruginosa , complicated by recurrent sepsis and multiorgan failure in a young patient with a history of sle .
a 26-year - old asian woman with a complex history of sle , diagnosed at age 14 years when she presented with malar rash , arthralgia , mouth ulcers , pulmonary vasculitis , strongly positive anti - nuclear antibody and anti - dsdna antibodies .
subsequently , she had idiopathic detrusor overactivity with repeated urinary tract infection . linked to her corticosteroid treatment she developed avascular necrosis of her elbow ( at that time , on prednisolone 6  mg daily ) .
the patient was also treated with hydroxychloroquine ( hcq ) , azathioprine ( aza ) ( 100  mg from 1999 to 2009 ) and had 14 courses of cyclophosphamide ( cyc ) ( a cumulative dose of 14  g ) and two of rituximab ( rtx ) ( two 1  g intravenous infusions separated by 2  weeks ) , the last being given in march 2012 for a sle flare manifested by severe vasculitic rash . immediately prior to b - cell depletion , her c3 level was 0.33  g / l ( normal : 0.651.65 ) , cluster designation ( cd ) 19 count was 0.146/l ( 0.110.69 ) , and immunoglobulin g level was 23.4  g / l ( 716 ) . in may 2012
, she presented to her local hospital with painful swelling of her left lower limb , she denied a history of trauma , and her inflammatory markers and ultrasonography were normal , and she was discharged . within 12  h
she was found at home with a glasgow coma scale of 6 , and was admitted to the intensive care unit ( icu ) . on examination ,
the patient was in septic shock with hypotension ( systolic blood pressure 60  mm  hg ) , tachycardia ( 135/min ) , and respiratory failure ( sao2 70% ) .
laboratory results showed erythrocyte sedimentation rate 96  mm / h ( normal : 17 ) , c - reactive protein 281  mg / dl ( 05 ) , white blood cells 15  400/l ( 300010  000 ) ( 97% neutrophils ; 1.9% lymphocytes ) , haemoglobin 9.6  g / dl ( 11.515.5 ) , platelet 50  000/l ( 150  000400  000 ) , na 138  mmol / l ( 135145 ) , creatine kinase 474  iu / l ( 26140 ) , urea 16.8  mmol / l ( 1.78.3 ) , alamine transaminase 384  iu / l ( 1035 ) , total bilirubin 11  mg / dl ( 0.31.9 ) , albumin 17  g / l ( 3450 ) , creatinine 290  mol / l ( 4992 ) and proteinuria 2.30  g / l ( 00,10 ) .
her c3 level was 1.0  g / l ( 0.651.65 ) , cd19 count was 0.001/l ( 0.110.69 ) , and immunoglobulin g level was 9.32  g /
cultures of muscle tissue only grew p aeruginosa , resistant to piperazillin - tazobactam ; therefore , she was treated with meropenem , teicoplanin and clindamycin . as her clinical condition
however , 1  week later , she deteriorated , with thick yellowish sputum , fever , respiratory distress and the chest x - ray showed right consolidation .
ciprofloxacin and teicoplanin were empirically started , and the patient 's clinical condition gradually improved . a week
after this treatment had finished , the patient became worse with a new left lower lobe consolidation , so the antibiotic therapy was changed to ceftazidime .
her lupus flared with a marked malar rash over both cheeks , so her steroids ( prednisolone ) were increased to 20  mg per day and hcq was restarted .
she was in the icu from may to august 2012 , but made a remarkable recovery and was discharged home with a steroid - tapering regimen and hcq .
later , she developed two more sle flares , which were treated again with cyc and rtx , achieving good response . at 18 months
follow - up , there is no evidence of new recurrent or severe ongoing infections .
most patients with nf ranged from 38years to 44  years , with a male to female ratio of 23  :  1 , and apparently an increased incidence in african and asian countries.3 the true incidence is not known ( it is estimated to be approximately 0.4 cases per 100  000 ) , with a reported mortality from 20% to as high as 80%.35 the causative agents of nf vary and include two main categories , polymicrobial ( type 1 ) and infection of group a streptococcal ( type 2 ) .
patients with sle have an increased risk of infections , due to immunological dysfunction and the use of steroids and immunosuppressive agents.6 other factors , such as the presence of a variant form of the fc receptor are also believed to contribute to the risk of pneumococcal infection.7 nf due to pseudomonas has very rarely been reported.8 
 9 the clinical presentation of patients with nf may be deceptively benign at onset , and it may not be possible to distinguish it clearly from minor soft tissue infections .
our patient was discharged from the original hospital before being admitted subsequently severely ill to university college hospital .
the lesion was rapidly progressive , probably due to her sle , and the prolonged steroid treatment and recent administration of cyc and rtx might have increased the risk of infection . during the initial period ,
exploration of the wound may be necessary even before the diagnosis is clear , particularly in a patient who is clearly toxic .
in addition to the present case , the other 31 cases of nf in sle patients that have been reported are summarised in table 1 .
the ages ranged from 12 years to 66  years , and 27 ( 84% ) were female .
most of the patients reported were asian ( 33% , 7 patients ) , 33% ( 7 patients ) hispanic and 19% ( 4 patients ) african  american .
the sites of infection included the upper or lower limb ( 60% , 17 patients ) , the face , neck or tongue ( 18% , 5 patients ) , the genital area ( 11% , 3 patients ) and the abdomen ( 11% , 3 patients ) .
nf type 1 was identified in 22 patients ( 71% ) and type 2 in 7 patients ( 23% ) , and when reported , the most common isolation was streptococcus ( 50% , 16 patients ) .
most of the patients presented with intense pain , poorly demarcated erythematous , swollen lesions over the limbs and systemic inflammatory response ; 28 patients ( 88% ) were receiving corticosteroids and 7 hcq ( 22% ) . additionally , use of other immunosuppressive drugs has been reported ( 5 cyc , 5 aza , 2 rtx , 1 mycophenolate , 1 methotrexate , 1 plasmapheresis ) before or at the time of infection .
other associated conditions have been identified , including nephritis ( 54% ; 15 patients of 28 reported ) , either during the current presentation or in the past , 13 ( 42% ) had active disease ( presumably those taking > 20  mg prednisolone or equivalent per day ) , 76% ( 13 of 17 reported ) had lymphopenia , 100% ( 12 out of 12 reported ) low serum albumin levels and 12 ( 37% ) had anaemia . interestingly , before the admission , 9 ( 28% ) reported a previous episode of infection : urinary , bartholin abcess , diarrhoea , respiratory tract infection , carious tooth , colitis , hepatitis c , cutaneous ulcers ( 2 ) , breast abscess and diverticulitis .
most patients responded to therapy , but 8 of the 32 patients died ( 25% ) , probably due to the infection or because of complications ( such as sepsis or pulmonary embolism ) .
the case presented here and the literature reviewed suggests that active disease , nephropathy , lymphopenia , anaemia , low serum albumin levels , immunosuppressive therapy and significant infections in the past , may constitute risk factors for the development of nf in patients with sle .
a high index of suspicion for the diagnosis is required , and surgical exploration should not be delayed , especially during the early stages , to improve the prognosis of this devastating complication .
 necrotising fasciitis ( nf ) is a rare infection of the subcutaneous tissue , known to be rapidly progressive and potentially fatal . 
 patients with systemic lupus erythematosus ( sle ) may be predisposed to this condition , and early clinical recognition can be difficult . 
 we report a case of necrotising fasciitis in a 26-year - old woman with sle . 
 she presented with painful swelling of her left leg , then developed clinical features of septic shock . 
 emergency debridement was performed . 
 intraoperative findings revealed nf and cultures grew pseudomonas aeruginosa . 
 the patient survived after a lengthy hospital admission , following several further debridements complicated by recurrent chest sepsis and multiorgan failure . 
 we also review and discuss the published cases of nf in sle patients . 