a 73-year - old female presented to our hospital with a painful blistering skin rash since 2 days . her past medical history was significant for hypertension on thiazides , hyperlipidemia , rheumatoid arthritis ( not on disease - modifying antirheumatoid drugs ) , and thrombocytopenia of unclear etiology . she first noticed the rash 2 days ago and noticed the lesions to be sudden in onset , spontaneously occurring , and progressively involving all areas of the body . the lesions were extremely painful to touch , nonpruritic , and would rupture with a bloody discharge . she denied arthralgias , photosensitivity , fevers or chills , cough , sore throat , hemoptysis , diarrhea or vomiting , epistaxis , hematemesis , or melena . of note , she had been prescribed a course of bactrim for a urinary tract infection , which she completed 2 days prior to the onset of the rash . she had a similar presentation 2 months ago , when she was admitted to our hospital for an extensive workup of the underlying etiology . examination of the skin , on current admission , was remarkable for numerous various - sized flaccid hemorrhagic bullae on a normal - appearing nonerythematous skin involving both the upper and lower extremities , including the palms , axillae , back , and inguinal regions ( fig 1 ) . . a careful examination of her oral cavity revealed ulcers on the palate and buccal mucosa with numerous 2- to 3-mm blood - filled blisters on the tongue . labs were significant for hemoglobin 8.8 g / dl , platelet count 17,000/mm , and albumin 3 g / dl . urinalysis was bland with mild proteinuria ( 30 mg / dl ) without red or white blood cell casts . autoimmune antibody panel was significant for positive antinuclear antibody titers ( 1 : 80 ) with a speckled pattern on immunofluoresence , low c3 complement ( 72 mg / dl ) , positive anti - rnp , anti - chromatin , and anti - smith antibodies . the following blood tests were either normal or within normal limits : white blood cell count , coagulation studies , adamts13 , serum protein electrophoresis , urticarial - induced basophil activation , 2 glycoprotein antibody ; anti - ssa , anti - ssb , anti - centromere , scl-70 , myeloperoxidase , serine protease , anti - bp180 , anti - bp230 , acute and chronic hepatitis panel . histopathology of the biopsy lesion showed interface change at the epidermo - dermal region with subepidermal blister formation , mild dermal fibrosis , and sparse interstitial neutrophilic infiltrate . immunohistological analysis was significant for positive igg basement membrane zone antibodies with a dermal pattern of localization on direct immunofluorescence and positive igg antinuclear antibodies on indirect immunofluorescence . negative iga , anti - bp180 , and anti - bp230 on immunofluorescence testing helped rule out linear iga bullous disease , anti - bp180 pemphigoid , and anti - bp230 pemphigoid , respectively . evidence of antibodies to type vii collagen suggested the diagnosis of epidermolysis bullosa acquisita ( eba ) versus bullous systemic lupus erythematosus ( bsle ) and made a drug - induced bullous reaction an unlikely possibility . our patient met 4 of the 11 american college of rheumatology ( acr ) sle criteria , i.e. , abnormal antinuclear antibody titers , positive anti - smith antibodies , immune thrombocytopenia , and oral ulcers . a diagnosis of bsle was made based on positive acr criteria , acquired vesiculo - bullous eruptions with compatible histopathological and immunofluorescence findings . this case illustrates one of many difficulties a physician encounters while arriving at a diagnosis from a myriad of immunobullous dermatoses . histopathological and immunofluorescence testing play a key diagnostic role in narrowing an extensive differential diagnosis of vesiculobullous disorders . bsle needs to be differentiated from pemphigoid , a much more common immunobullous disorder in elderly patients over 70 years old . bsle must also be differentiated from eba , a disorder which shares many clinical and histopathological features of bsle . immunopathological criteria of bsle are similar to eba and can present a significant diagnostic dilemma , especially in a patient with no known prior history of sle . differentiating these two disorders is important to inform the physician on optimum management and prognosis . a careful history taking focusing on characteristics of the lesions , relevant serologies , and response to dapsone help differentiate these two disorders . lesions of eba are predominantly mechanobullous in nature and characteristically occur on trauma - exposed areas like the elbows , knees , ankles , and dorsum of the hands . also , eba skin lesions are more resistant to treatment with steroids and other immunomodulatory agents , an important differentiating characteristic . positive antinuclear antibody titers with fulfillment of acr sle criteria and response to steroids favored the diagnosis of bsle in our patient [ 3 , 6 ] . it was her first clinical manifestation of elderly - onset sle , a specific sle subset with significantly poor morbidity and mortality outcomes [ 7 , 8 ] . bsle is a very uncommon and nonspecific cutaneous manifestation of sle occurring in less than 1% of patients . it generally occurs in middle - aged adults but has also been rarely reported in the elderly . bsle may occur as the initial manifestation of sle and requires the diagnostician to maintain a high degree of clinical suspicion . secondly , sle features are common in rheumatoid arthritis , and the two diseases can coexist in the same individual , as in our patient . our patient was initiated on empiric pulsed steroids , while diagnostic workup was in progress , and showed a good clinical response to treatment ( fig 2 ) . bsle lesions have a dramatic response to dapsone , making it the therapeutic agent of choice with a significant diagnostic value . responses to corticosteroids are less definite , but case reports have documented effectiveness to steroid administration . it is important for internists and dermatologists alike to be aware of and differentiate this uncommon and nonspecific cutaneous sle manifestation from a myriad of disorders presenting with vesiculobullous skin eruptions in the elderly . at the time of this writing , the patient was asked to follow up with the dermatologist to discuss her diagnosis and institute definitive management . the authors have no affiliations with or involvement in any organization or entity with any financial or nonfinancial interest in the subject matter or materials discussed in this work .
vesiculobullous eruptions in the elderly represent a diverse range of varying pathophysiologies and can present a significant clinical dilemma to the diagnostician . 
 diagnosis requires a careful review of clinical history , attention to detail on physical and histomorphological examination , and appropriate immunofluorescence testing . 
 we describe the case of a 73-year - old female who presented to our hospital with a painful blistering skin rash developed over 2 days . 
 examination of the skin was remarkable for numerous flaccid hemorrhagic bullae on a normal - appearing nonerythematous skin involving both the upper and lower extremities . 
 histopathology of the biopsy lesion showed interface change at the epidermo - dermal region with subepidermal blister formation , mild dermal fibrosis , and sparse interstitial neutrophilic infiltrate . 
 immunohistological analysis was significant for positive igg basement membrane zone antibodies with a dermal pattern of localization on direct immunofluorescence and positive igg antinuclear antibodies on indirect immunofluorescence . 
 evidence of antibodies to type vii collagen suggested the diagnosis of epidermolysis bullosa acquisita versus bullous systemic lupus erythematosus ( bsle ) . a diagnosis of bsle was made based on positive american college of rheumatology criteria , acquired vesiculo - bullous eruptions with compatible histopathological and immunofluorescence findings . 
 this case illustrates one of many difficulties a physician encounters while arriving at a diagnosis from a myriad of immunobullous dermatoses . 
 also , it is important for internists and dermatologists alike to be aware of and differentiate this uncommon and nonspecific cutaneous sle manifestation from a myriad of disorders presenting with vesiculobullous skin eruptions in the elderly .