a 76yearold man underwent a computed tomography ( ct ) scan of the abdomen for investigation of a pancreatic lesion . the following day , he developed an itchy rash around the waist which spread to the torso and limbs . six days later , he presented to the emergency department with extensive skin involvement and symptoms of general fatigue . , there was a widespread , urticated , and edematous confluent exanthem on the torso ( fig . 1 ) ; on the limbs there were discrete urticated lesions reminiscent of targets but with extensive purpura ( fig . five years earlier , he had undergone a ct chest scan with rcm and had no reported complications . he was taking no other medications and there was no history of previous drug allergies . blood tests revealed an elevated white cell count of 20.54 ( 10/l ) , with a neutrophilia of 16.6 ( 10/l ) and an eosinophilia of 2.12 ( 10/l ) . there was a mild acute kidney injury with creatinine 134 mmol / l , urea 11.0 mmol / l . histology of a skin biopsy revealed mild acanthosis and spongiosis with occasional intraepidermal apoptotic keratinocytes . there was a perivascular inflammatory cell infiltrate composed of eosinophils , lymphocytes , and neutrophils ; extravasation of red blood cells was also seen ( fig . the dermatopathological features were suggestive of a drug reaction . a 4mm punch biopsy of skin from the abdomen , showing spongiosis , a perivascular inflammatory cell infiltrate , and red blood cell extravasation . the patient was prescribed oral prednisolone 30 mg and 0.1% mometasone furoate ointment to the skin . most allergic reactions to rcm are immediate , however , delayedtype hypersensitivity responses are well recognized 1 , 2 . in this situation , sensitization to rcm occurs when a patient is first exposed ; subsequent rcm administration activates the immune mechanism resulting in a tcell mediated hypersensitivity reaction developing within 2448 h. clinically , delayed reactions to drugs present to dermatology in a variety of forms . those with constitutional upset , internal organ involvement , leukocyte activation , and a florid drug rash are usually termed drug hypersensitivity syndrome ( dhs ) or drug reaction with eosinophilia and systemic symptoms ( dress ) . more specifically , the systemic abnormalities accompanying dress are fever , lymphadenopathy , hematological derangement ( typically eosinophilia and atypical lymphocytosis ) , and internal organ involvement ( frequently liver injury ) 3 . in dress , there is usually a protracted latency period between drug ingestion and onset of the reaction ( between 4 and 8 weeks ) . commonly , the disorder takes several weeks to settle and can enter a chronic phase 4 . there is little epidemiological data on the exact incidence of dress , as it presents in a variety of forms , and thus may often go undiagnosed . a scoring system for dress developed by regiscar ( an international severe drug eruption registry ) , quantifies the physical signs and abnormal laboratory parameters to produce a value which defines the diagnosis 5 . the score is based on clinical features , extent of eosinophilia , atypical lymphocytosis , internal organ involvement of a defined severity , and the presence of an extensive rash . a score of 4 or 5 ( out of 9 ) is classified as a probable case ; a score of 5 or above is a definite case . however , in daytoday clinical practice , there are patients who develop a drug reaction with systemic features which is suggestive of the dress phenotype , but which fails to exceed the diagnostic threshold . these patients can be considered to have a minor form of dress . our patient 's clinical manifestations included an extensive dermatosis , lymphadenopathy , mild acute kidney injury , and mild eosinophilia . however , there was no fever , no other solid organ involvement , and resolution of the reaction was swift . application of the regiscar dress criteria in this case yielded a score of 3  that is , neither a probable nor a definite case of dress . we conclude that our patient sustained a systemic drug hypersensitivity reaction to rcm , but of a degree not severe enough to diagnose dress . our case illustrates the incomplete form of dress , which displays some but not all of the features of the fullblown syndrome . these cases may go unrecognized , as they do not fulfill the complete diagnostic criteria . typically , the drug exposure latency period in these cases is shorter than that in dress . in addition , minidress reactions are less likely to produce a protracted illness , compared to dress . the prognosis in minidress is good , and most cases respond swiftly and fully to a short course of systemic corticosteroid .
key clinical messagedrug reaction with eosinophilia and systemic symptoms ( dress ) is a delayed drug reaction defined by physical signs and laboratory parameters . 
 minidress is a new entity , in cases that display some but not all features of dress . 
 cases of minidress have a less protracted course , and respond well to systemic corticosteroid treatment .