a 36-year - old woman presented at our institution ( gachon university gil hospital ) with erythematous confluent maculopatches on her face , trunk , and palms ; jaundice ; fatigue ; pruritus ; and aggravation of skin lesions over the previous week . she had been previously diagnosed as having erythema multiforme 2 weeks earlier at a private dermatology clinic and had also been administered dapsone with oral antihistamines ( mequitazine and cetirizine ) and topical corticosteroid for 8 months . on admission , her vital signs were a blood pressure of 110/70 mm hg , heart rate of 78 beats / min , respiratory rate of 18 breaths / min , and body temperature of 38.8. she reported no night sweats , loss of weight , or arthralgia . a physical examination conducted at presentation revealed bilateral , multiple enlarged lymph nodes on both sides of the neck with splenomegaly . all of the nodes were non - tender , firm , and measured 0.5 cm to 1.0 cm in diameter . laboratory tests results were as follows : hb 11.2 g / dl , white blood cell 13,070/mm ( segmented neutrophils 24% , lymphocytes 66.3% , and eosinophils 0.1% ) , platelets 245,000/mm , total bilirubin 5.4 mg / dl , direct bilirubin 3.8 mg / dl , aspartate aminotransferase / alanine aminotransferase ( ast / alt ) 233/366 u / l , lactate dehydrogenase 1,610 iu / l ( normal range , 200 to 485 iu / l ) , and an international normalized ratio of 1.25 . she was negative for hepatitis b surface antigen , anti - hepatitis c virus ab , and anti - human immunodeficiency ab , but positive for hepatitis b surface antibody ; and positive for anti - nuclear ab , but negative for rheumatoid factor , anti - neutrophil cytoplasmic ab , anti - ro ( ss - a , b ) ab , and anti - smith ab . serology tests showed no evidence of active epstein - barr virus ( ebv ) infection and no bacterial growth was found during a blood culture study . an excisional biopsy of a 1.0 cm cervical node showed diffuse polymorphic lymphoid hyperplasia with effacement of the normal architecture and abundant high endothelial venules ; the cellular infiltrate was polymorphic , with abundant transformed lymphocytes and plasma cells ( fig . immunohistochemically , the majority of infiltrating atypical lymphocytes were cd3 + t - cells ( fig . 2a , b ) , and some activated large cells were reactive for cd30 ( fig . 2c ) . 2d ) , and infiltrating atypical t - cells were negative for cd10 , bcl-6 , and ebv by in situ hybridization . for a definitive diagnosis , a molecular study on the rearrangement of the t - cell receptor ( an abdomino - pelvic computed tomography ( ct ) scan revealed splenomegaly ( 14 cm ) , an enlarged portocaval lymph node ( 1.7 cm ) , and gallbladder wall edema ( fig . no evidence of lymphomatous involvement was found by chest ct or a bone marrow trephine biopsy . because aggravation of the skin eruption persisted and the liver function test remained abnormal , the possibility of dhs ( exfoliative dermatitis , acute hepatitis , and multiple lymphadenopathy ) was raised . the findings of a transjugular liver biopsy were compatible with drug - induced hepatitis manifesting as granulomatous inflammation ( fig . 5 ) . no evidence of lymphomatous hepatic involvement was found . in view of her skin lesions , medication history , and age accordingly , low dose prednisolone ( 30 mg / day ) per os was started after transjugular liver biopsy to relieve the dapsone - induced skin lesions and hepatitis . her total bilirubin , ast , and alt values also normalized after 3 weeks of prednisolone , which was then tapered over a month . follow - up ct scans conducted 3 and 6 months after presentation showed that the size of the cervical lymph nodes and spleen had normalized , and produced no other findings suggestive of lymphoma progression ( fig . it was first identified in the early 1940s following the introduction of hydantoin and its derivatives for the treatment of convulsive disorders.3 several drugs other than hydantoins , such as tamoxifen , amlodipine , carbamazepine , and valsartan , have also been reported to cause pseudolymphoma.4 - 7 pathologically , lymph nodes of pseudolymphoma show obliteration of the normal architecture , along with hyperplasia of the reticulum cells and other elements , with frequent mitoses . they also show eosinophilic leukocyte infiltration , focal necroses , and phagocytosis , but no reed - sternberg cells.8 clinically , systemic reactions are usually combined with pseudolymphoma , fever , skin eruption , hepatitis , and less frequently with hepatosplenomegaly.8 the differential diagnosis of multisystem illness in our patient included : drug reaction with eosinophilia and systemic symptom ( dress ) syndrome and its variants , vasculitis ( churg - strauss syndrome ) , hypereosinophilic syndrome , toxic epidermal necrolysis syndrome ( tens ) and stevens - johnson syndrome . churg - strauss syndrome is a medium and small vessel autoimmune vasculitis , which leads to necrosis , and mainly involves the blood vessels of the lungs , gastrointestinal system , and peripheral nerves , though it can also affect the heart , skin , and kidneys . hypereosinophilic syndrome is characterized by a persistently elevated eosinophil count ( 1,500 eosinophils / mm ) in the blood for at least six months without any recognizable cause . tens and stevens - johnson syndrome are characterized by diffuse erythematous or purpuric macules with involvement of more than 30% of the body surface area with epidermal necrosis with mucosal membrane involvement . the incidence of dhs ranges from 0.5% to 3% , and the median latency before symptom onset can be as little as 2 to 6 hours in previously sensitized patients , to as late as 6 months.9 the mechanism of dhs has not been clearly defined.9 however , a few mechanisms have been proposed , for example , dhs might be a combination of type i , type iv , and perhaps type iii gel and coombs hypersensitivity reactions,10 or alternately , it could be a modified form of graft - versus - host disease mediated by activated t - lymphocytes.10 it is worth noting that although dapsone hepatotoxicity is a dose - dependent effect , dhs is not.10 the classic triad of dhs consists of fever , eruption , and internal organ involvement , although hepatitis , exfoliative dermatitis , lymphadenopathy , and hemolytic anemia might be observed in varying combinations and sequences.11 in addition , cholangitis has also been described as a component of dhs.11 cutaneous lesions can range from erythematous papules , as in our patient , to plaques , pustules , and eczematous lesions . some patients may also develop severe dermatitis and complications , such as stevens - johnson syndrome or toxic epidermal necrolysis.12 however , the severity of cutaneous changes is not correlated with the severity or extent of internal organ involvement.12 the histologic findings of the cervical lymph node were compatible with angioimmunoblastic t - cell lymphoma , and without clinical information , it is difficult to exclude this possibility . however , a diagnosis of dapsone - associated lymphadenopathy was made because of a definite medication history capable of causing a systemic hypersensitivity reaction , and because the lymphadenopathy occurred only after the systemic hypersensitivity reaction . moreover , both tcr- and igh gene rearrangement studies showed polyclonality and infiltrating atypical t - cells and no aberrant expression of bcl-6 or cd10 . for polymerase chain reaction ( pcr ) amplification of the tcr- locus pcr followed by single - stranded conformational polymorphism analysis were performed.13 thus , in view of the clinical and pathologic characteristics , we concluded that the manifestations were compatible with dhs . furthermore , we presumed that the hepatitis with hepatosplenomegaly was due to a reactive change induced by dhs rather than lymphomatous involvement , and the lymphadenopathy was actually a pseudolymphoma rather than true angioimmunoblastic t - cell lymphoma ( aitl ) , which is commonly encountered in the seventh decade of life.14 in fact , the findings of a transjugular liver biopsy were compatible with drug - induced hepatitis . the pathologic findings of the liver biopsy were granulomatous inflammation , which is observed in a large number of drug - associated injury cases.15 in the case described here , had we adopted a combination chemotherapy , such as cyclophosphamide , adriamycin , vincristine and prednisolone ( chop ) for aitl , the unnecessary treatment may have caused further hepatic impairment . to our knowledge , this is the first report of dapsone - induced lymphadenopathy mimicking aitl . our experience of this case cautions physicians that lymph node biopsy results suggestive of lymphoma in the situation of drug - induced systemic hypersensitivity reaction should be an interpretation of the biopsy before deciding on the optimal treatment .