eed is a localized , low - grade form of leukocytoclastic vasculitis of unknown pathogenesis characterized by persistent , symmetrical , red - purple papules , nodules , and plaques affecting the extensor surfaces of the extremities , the ears , trunk and buttocks .
dermatitis herpetiformis is an autoimmune blistering disease characterized by granular deposits of immunoglobulin a ( iga ) in dermal papillae .
the common link between these two disorders is the deposition of ig a antibodies , underlying gluten sensitivity in both , their association with celiac disease and response to treatment with dapsone .
a 50-year - old male presented with firm skin - colored and erythematous nodules over the knuckles , elbows , buttocks , knees , and lower legs which gradually increased in size in since 3 years duration [ figure 1 ] .
complete blood picture , liver function tests , urine routine , blood sugar were within normal limits .
biopsy of the nodules of the knuckles showed focal parakeratosis and mild spongiosis in the epidermis , perivascular neutrophilic infiltrate in the dermis , neutrophils in the vessel wall and leukocytoclasia [ figure 2 ] .
immunofluorescence showed linear iga deposits in the basement membrane zone and weak granular perivascular c3 and fibrinogen deposits [ figure 3 ] .
four years ago itchy vesicles over the back and arms were detected in the patient .
he was administered dapsone which leads to disappearance of lesions with recurrence after stopping treatment . with the clinical presentation , biopsy and immunofluorescence
results , a diagnosis of erythema elevatum diutinum on a background of dermatitis herpetiformis was made .
skin - colored nodules over the knuckles neutrophilic vasculitis with leucocytoclasia ( h and e , 400 ) linear iga deposits in the basement membrane zone dermal papillary microabscess ( h and e , 400 )
erythema elevatum diutinum ( eed ) is a rare cutaneous condition that initially presents as leukocytoclastic vasculitis ( lccv ) of the skin and later resolves with fibrosis clinically characterized by persistent red - purple to yellow papules , plaques , and nodules .
the symmetrical lesions typically affect the acral surfaces of the body , especially the extensor surfaces of the hands , but other areas such as the buttocks may also be involved .
antecedent bacterial infections , collagen vascular diseases , myeloproliferative diseases , human immunodeficiency virus infection , cryoglobulinemia , wegener granulomatosis , crohn disease , systemic fungal diseases , iga paraproteinemia , and other associations have been reported .
histopathologically , eed initially presents as a leukocytoclastic vasculitis ( lccv ) with polymorphonuclear neutrophils , extravasated red cells , nuclear dust , and fibrin deposits in the walls of the small arterioles .
dermatitis herpetiformis ( dh ) is characterized by chronic , intensely pruritic , polymorphic , vesicles usually appearing on elbows , knees , buttocks , and scalp associated with gluten - sensitive enteropathy there are granular iga deposits in the dermal papillae by the direct immunofluorescence in the perilesional skin of patients with dermatitis herpetiformis .
the close association of iga with erythema elevatum diutinum and dermatitis herpetiformis is well known . because of the association with iga , the presence of erythema elevatum diutinum in a patient with chronic dermatitis herpetiformis is not surprising .
the iga in the skin may be an epiphenomenon or may represent deposition in the skin along with other immune complexes . 
 
aftab mn et al . have reported a case of erythema elevatum diutinum arising in the setting of dermatitis herpetiformis .
they concluded that iga immune complexes within the basement membrane zone region may trigger a cascade that eventuates into a blister or the formation of the chronic vasculitis of erythema elevatum diutinum .
 erythema elevatum diutinum ( eed ) is a rare skin disease that initially presents as leucocytoclastic vasculitis and later resolves with fibrosis . 
 dermatitis herpetiformis is an autoimmune blistering disease characterized by granular deposits of immunoglobulin a ( iga ) in dermal papillae . 
 we report a rare association of these two disorders . 
INTRODUCTION
CASE REPORT
DISCUSSION