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Paper text:
systemic sclerosis ( ssc ; scleroderma ) is an autoimmune disease characterized by vasculopathy and fibrosis of multiple organs including the skin , lungs , and gastrointestinal tract ( git ) .
this chronic disease process results in pain and pruritus , two distinct , but interacting phenomena .  
pruritus is most common in the early stages of disease and may subside as the disease progresses .  
ssc patients that complain of pruritus have more significant skin involvement , more severe finger ulcers , worse respiratory symptoms , and a greater number of git complaints . of interest , pruritus
although pruritus is associated with significant disability , management guidelines for pruritus in ssc do not exist .  
pruritus is also a feature of primary biliary cirrhosis ( pbc ) , which   occurs more commonly in ssc than the normal population .
there is a known association with pbc and oxidative stress as well as endothelial dysfunction .
pharmaceutical management suggestions for treatment of pruritus in pbc include cholestyramine , rifampin , sertraline , and naloxone .
more recently , pilot trials of low - dose naltrexone hydrochloride ( ldn ) , which is a pharmaceutical similar to naloxone , have recently gained increasing recognition for treating chronic pain associated with fibromyalgia , multiple sclerosis , and crohn 's disease [ 810 ] .   
evidence supporting the hypotheses that increased opioid - mediated neurotransmission in the brain is a mechanism of pruritus and that central opioidergic tone is increased in cholestasis provides a rationale for treating the pruritus of cholestasis with opiate antagonists in pbc .  
another potential mechanism of action of ldn is through attenuation of the production of proinflammatory cytokines and superoxides potentially mediated by activity of toll - like receptor 4 .  
modulation of mitochondrial apoptosis has also been proposed as a mechanism of ldn . in ssc ,
thus , an agent that potentially modulates oxidative stress is attractive as an emerging therapeutic in ssc . given the putative mechanisms of action of ldn and the roles of these various pathways in ssc , our hypothesis is that ldn may be a reasonable agent to treat pruritus in ssc .
in this case series we report three ssc patients who presented to the university of utah ssc center with the chief complaint of pruritus .
two patients were of diffuse cutaneous ssc subtype ( dssc ) ; the other one was limited ssc subtype ( lssc ) .
the disease duration from the first non - raynaud 's phenomenon symptom varied from 1 year to 11 years .
raynaud 's phenomenon onset was within the same year of diagnosis in two patients , and three years prior in one patient .
all patients reported pruritus as an important feature of disease since onset of ssc and did not attribute it directly to change in skin thickening or gi manifestations .
they all reported that  itchiness  of the skin had been present for > 6 weeks and was unresponsive to antihistamines on all days .   none had urticaria .
they all denied a history of eczema or skin conditions other than ssc , any new product , or infectious exposures and attributed this symptom to ssc .
a ten - point faces scale was used to assess pruritus . on this scale 0 , is no symptoms , 1 very mild , 2 discomforting , 3 tolerable , 4 distressing , 5 very distressing , 6 intense , 7 very intense , 8 utterly horrible , 9 excruciating , 10 unimaginable / unspeakable .
all patients completed a university of los angeles scleroderma clinical trials consortium gastrointestinal tract questionnaire ( git 2.0 ) .
the git 2.0 is patient - reported outcome measure to assess health - related quality of life ( hrqol ) and git severity in ssc [ 17 , 18 ] .
this 34-item instrument has seven scales : reflux , distention / bloating , diarrhea , fecal soilage , constipation , emotional well - being , and social functioning and a total gi score ( a higher score denoted worse hrqol ) .
all scales are scored from 0.0 ( better hrqol ) to 3.0 ( worse hrqol ) except diarrhea and constipation scales that range from 0.0 to 2.0 and 0.0 to 2.5 , respectively .
the total gi score is the average of 6 of 7 scales ( excludes constipation ) , and total gi score is scored from 0.0 ( better hrqol ) to 3.0 ( worse hrqol ) .
each scale is further divided into 3 groups by severity : none - to - mild , moderate , and severe - to - very severe .
these were calculated based on anchors included in the original published data and data collected in a recent national scleroderma foundation online survey and available online at http://uclascleroderma.researchcore.org .
the instrument takes 68 minutes to be completed and has been shown to have acceptable reliability and validity [ 17 , 19 ] .  
additionally each patient had a modified rodnan skin score ( mrss ) as part of their routine care at baseline ( table 1 ) .   
a marker of inflammation ( c - reactive protein ) was normal in all patients .
none of the patients had an eosinophilia ( < 0.4  k/l ) on peripheral blood smear .  
two patients had skin biopsy performed as part of another clinical study . a computer - assisted image analysis of two of the biopsy specimens revealed that at baseline there was not an increase in mast cells greater than those present in a healthy control ( figures 1 and 2 ) .   from a treatment perspective ,
all patients were rna polymerase iii positive , making a trial of corticosteroids for treatment of pruritus an unattractive option due to an increase risk of scleroderma renal crisis .
all patients denied respiratory complaints , had no evidence of pulmonary arterial hypertension on echocardiogram , and had normal pulmonary function tests .  
each patient was initiated on ldn 2  mg by mouth at bedtime for the first month . using dosing recommendations from another trial and phone call monitoring for adverse effects ,
the dose was increased by 1  mg by mouth at bedtime each week ( 0.5  mg the final week ) up to a maximum dose of 4.5  mg .  
one patient requested to maintain the dose of 2  mg by mouth at bedtime , as she felt it was working well and did not wish to incur additional cost .
all patients repeated the git 2.0 , and a mrss was done at each visit .  
no other medication change , including use of over - the - counter agents , was allowed for any of these patients during the treatment period .
one patient implemented head - of - the - bed elevation for reflux management , and two patients increased fluid and dietary fiber intake for symptoms of constipation .
all patients reported an improvement in pruritus on a faces scale after initiating ldn ( table 1 ) . in two different patients ,
pruritus completely resolved on ldn . in two patients a trend in improvement in mrss was seen at two months , which is not clinically significant .
all patients there was an improvement in total git 2.0 scores as well as in constipation and distention / bloating subscales .
no adverse drug effects were reported with the exception of two nights of insomnia reported in a single patient .
the pathogenesis of chronic ( > 6 weeks duration ) pruritus is complex and involves a network of resident cells ( such as mast cells , keratinocytes , and sensory neurons ) and transient inflammatory cells within the skin .
because of the association of pruritus with quality of life ( qol ) in ssc , more attention to potential methods for intervention is warranted .
this small case series suggests a potential role for ldn for ssc with pruritus .  
additionally , a possible improvement in mrss and in git symptoms may also result from use of ldn .    
autoimmune gastrointestinal disorders such as   inflammatory bowel disease ( ibd ) , gluten - sensitive enteropathy , and pbc have also   been associated with pruritus .
evidence supports that increased opioid - mediated neurotransmission in the brain may be a mechanism of pruritus in pbc .  
although the real biological mechanism of ldn is not known , ldn may modulate pruritus through opioid - mediated actions or a reduction of inflammatory mediators [ 25 , 26 ] .  
as such , a better understanding of the interaction of the git and pruritus is warranted .  
ssc patients commonly have diarrhea , constipation , and distention / bloating that may mimic git hypersensitivity .  
whether the git is responsible for the pruritus in ssc or whether the git and skin are reacting to a similar stimulus or endogenous immune response is unknown .
mast cells have been suggested to have an important role in ssc as well as in functional bowel disorders [ 28 , 29 ] .   however
, computer - assisted analysis of skin biopsy specimens in two of our patients did not reveal an abnormal percentage of mast cells .  
clearly a larger number of patients and a double - blind placebo - controlled trial are needed to define the therapeutic potential of ldn in ssc .  
softer skin  was not validated by a significant change in mrss and could be attributed to the natural history of disease rather than to naltrexone .  
psychological and physiological predictors of pruritus response as well as minimally important differences in the ten - point faces scale need to be defined .
gastrointestinal biopsy specimens would have been helpful for correlating to skin biopsy specimens for defining potential morphologic and histochemical change .  
nonetheless , this series suggests ldn may be an effective , highly tolerable , and inexpensive treatment for pruritus in ssc and further supports a potential role for computer - assisted quantification of inflammatory cell types in skin biopsies to guide selection of therapeutics .
pruritus is a common symptom in systemic sclerosis ( ssc ) , an autoimmune disease which causes fibrosis and vasculopathy in skin , lung , and gastrointestinal tract ( git ) . 
 unfortunately , pruritus has limited treatment options in this disease . 
 pilot trials of low - dose naltrexone hydrochloride ( ldn ) for pruritus , pain , and quality of life ( qol ) in other git diseases have been successful . in this case series we report three patients that had significant improvement in pruritus and total git symptoms as measured by the 10-point faces scale and the university of california los angeles scleroderma clinical trials consortium gastrointestinal tract 2.0 ( ucla sctc git 2.0 ) questionnaire . 
 this small case series suggests ldn may be an effective , highly tolerable , and inexpensive treatment for pruritus and git symptoms in ssc .