non - lichenoid cutaneous reactions secondary to imatinib mesylate are the most common non - hematologic adverse reactions associated with its use.lichenoid drug eruption usually occurs on the photo - exposed parts of the skin . non - lichenoid cutaneous reactions secondary to imatinib mesylate are the most common non - hematologic adverse reactions associated with its use . imatinib mesylate ( i m ) is an anticancer drug judiciously designed to selectively inhibit certain protein tyrosinase kinase implicated in oncogenesis . i m has been used to treat chronic myeloid leukemia ( cml ) , gastrointestinal stromal tumors ( gist ) , and dermatofibrosarcoma protuberans . cutaneous reactions to i m have been reported to occur in 9.5 - 69% of patients in different series . non - lichenoid cutaneous reactions due to i m have been well - documented in the literature and are the commonest non - hematologic adverse reactions associated with its use . a case of a generalized lichenoid drug eruption ( lde ) associated with imatinib mesylate therapy has been described here for its rarity and unusual clinical presentation . in view of the fact that the clinical usage of i m is growing it is thus important to realize the potential of i m to produce lichenoid drug reaction and to differentiate this entity from idiopathic lichen planus . reports of im - associated lichenoid drug eruption in the english language literature , described in the pubmed and medline database , have also been reviewed . a 63-year - old man was referred to the dermatology department with a 3-week history of acute onset , raised , itchy , purple - colored fairly generalized skin lesions over his body . two months before the onset of the skin lesions the patient was put on monotherapy with imatinib mesylate ( i m ) ( 400 mg / day ) for the treatment of cml . considering the skin eruption , i m had been discontinued ten days prior to his first dermatological consultation . according to the patient , stoppage of the drug led to mild improvement of the skin lesions . cutaneous examination revealed numerous , well - defined , violaceous , discrete and coalescing papules and plaques over the limbs , abdomen , chest , and the back . there was fine scaling but no evident vesiculation , oozing or crusting [ figures 1 and 2 ] . ( a and b ) numerous violaceous , coalescing papules and plaques exhibiting koebnerisation and fine scaling ( a and b ) close - up showing purple - colored coalescing papules and plaques with fine scaling lesional punch biopsy specimens were obtained from two different sites . histopathological examination [ figures 3 and 4 ] of both the specimens showed similar features . epidermis showed hyperkeratosis with focal parakeratosis , irregular acanthosis and focal wedge - shaped hypergranulosis . focal basal cell degeneration and pigment incontinence were found . an upper dermal band - like infiltrate comprising mononuclear cells and eosinophils was present at the dermoepidermal junction . serological tests for human immunodeficiency virus ( hiv ) and hepatitis b and c were negative . ( a ) hyperkeratosis , irregular acanthosis , and focal wedge - shaped hypergranulosis , upper dermal band - like cellular infiltrate at the dermoepidermal junction and a few colloid bodies . ( b ) focal basal cell degeneration and melanin incontinence ( h and e , 400 ) . ( c ) eosinophil in the dermis ( marked by arrow ) ( h and e , 1000 ) ( a ) focal parakeratosis , ( marked by arrows ) irregular acanthosis , wedge - shaped hypergranulosis , focal basal cell degeneration , pigment incontinence , and upper dermal band - like infiltrate ( h and e , 100 ) . ( b and c ) prominent parakeratosis ( marked by arrows ) ( h and e , 400 ) based on the clinical presentation and histopathological examination , a diagnosis of generalized lde associated with i m was made . according to the naranjo probability scale for adverse drug reaction , the patient was treated with topical clobetasol propionate ( 0.1% ) cream application over the active skin lesions as well as oral antihistamines . within a couple of weeks , almost all the lesions healed with residual post - inflammatory hyperpigmentation [ figure 5 ] and new lesions stopped appearing . since the type of the adverse cutaneous drug reaction was not life- threatening , i m was gradually re - introduced to achieve a dose of 400 mg / day by hemato - oncologists . after re - introduction of imatinib , he had a few new lesions of lp over the next couple of months . however , he was being maintained on intermittent topical steroid application over the active lesions with excellent control of the skin condition . non - lichenoid dermatoses associated with i m therapy may include : maculopapular eruption , edema , stevens - johnson syndrome , toxic epidermal necrolysis , acute generalized exanthematous pustulosis , vasculitis and mycosis fungoides - like eruption . other less commonly described side effects of i m include , hypopigmentation , pityriasis rosea , psoriasis , neutrophilic eccrine hidradenitis , sweet 's syndrome , erythema nodosum , epstein - barr virus - positive cutaneous b - cell lymphoproliferative disease , follicular mucinosis and pseudolymphoma - like drug eruptions amongst others . on the other hand , only a few reports of im - associated lichenoid drug eruption have been described over the last decade . lichenoid drug eruption is an interface dermatitis induced by ingestion , contact or inhalation of a variety of drugs and has a latent period that ranges from a few weeks to several months . the latent period between the start of treatment and the appearance of lde may be shortened if the individual has had earlier exposure to the agent . lde have been described with a wide gamut of medications . as newer agents continue to be introduced and prescribed , the list of the offending drugs for lde is ever expanding . these may commonly include , angiotensin converting enzyme inhibitors , thiazide diuretics , gold , antimalarials , penicillamine , nonsteroidal anti - inflammatory agents , dental amalgams , sulfasalazine , -blockers , and proton - pump inhibitors , to name afew . clinically , these eruptions are often look like those of lichen planus ( lp ) . lde commonly presents as skin lesions comprising papules or plaques , usually on the photo exposed parts of the skin . lesions of lde are often larger in size , less monomorphic and more prone to be eczematous and associated with desquamation in contrast to that of lp . . patients with lde are often taking more than one medication , which may make the recognition of the causative agent tricky . histopathologically , a number of findings are more typical of lde and comprise focal parakeratosis , presence of eosinophils and plasma cells , and a deeper perivascular and periadnexal infiltrate . however , one interesting and unusual finding in the present case was the presence of lde in both photo exposed and covered parts of the body . it is worth mentioning that , in the setting of cml , im - associated oral lde must be differentiated from idiopathic lichen planus , paraneoplastic pemphigus , and graft - versus - host disease . specific causes of imatinib induced skin lesions remain elusive . due to its fairly low molecular weight , the dose dependence of adverse reactions favors the assumption that imatinib related cutaneous reactions are mediated by changes in tyrosinase kinase signaling rather than immunologic mechanism . it has been also proposed that the lesions in oral lde may be closely correlated with the altered expression of epidermal markers caused by imatinib . imatinib ,  lichenoid drug eruption ,  lichenoid eruption and  cutaneous lichenoid eruption. table 1 summarizes reported cases of im - associated lde in the english language literature as found in these databases . the severity of lde due to i m varied from mild to severe and the extent of involvement varied from localized to extensive . profile of patients of lichenoid drug eruption associated with imatinib mesylate therapy some of the reported patients had only mucosal lesions some had only cutaneous lesions and the remainder had both lesions . all the patients took imatinib mesylate in the dose of 400 mg / day or above . this observation probably supports the view that the im - associated lde are dose dependent rather than immunogenic in nature . most common indication of i m usage was cml . in a few cases i m was used to treat gist . the time interval between the adverse effects appeared and the initiation of i m ranged from one month , to 15 months . in some cases such drug eruptions have led to temporary or permanent discontinuation of i m . the use of a systemic or topical corticosteroid and a gradual increase in the i m dose may be a useful and practical approach to permit the continuation of treatment with i m . has shown that acitretin may be successfully used to treat im - associated lde , enabling the continuation of the effective i m dosage . in the present patient , temporary discontinuation of i m improved the condition . on restarting and gradually increasing the dose of i m to 400 mg / day , only a few lesions of lp reappeared . it is important to understand the potential of i m to produce lde and to differentiate this entity from its idiopathic counterpart . moreover , early recognition of the morphological pattern of such drug eruption is crucial to prevent the subsequent discontinuation of i m , which has radically changed the treatment and prognosis of cml and gist . generalized lichenoid drug eruption may rarely be associated with imatinib mesylate therapy.imatinib mesylate induced lichenoid drug eruption may involve both the photo exposed and covered parts of the body . imatinib mesylate induced lichenoid drug eruption may involve both the photo exposed and covered parts of the body .