fixed drug eruptions ( fdes ) is an entity that is frequently encountered by all physicians . they are clinically distinct with characteristic recurrences at the same sites on re - exposure to offending drug . recent studies from india suggest that fixed drug eruptions ( fdes ) account for 2043% of all cutaneous adverse drug reaction ( cadr ) patterns . exact pathogenesis remains obscure but intraepidermal cd8 t cells that persist at the previous injury site mediate and are directly implicated in the epidermal injury causing localized cutaneous changes . fde has multiple variants , including generalized , linear , bullous , urticarial , pigmenting , nonpigmenting , wandering , eczematous , psoriasiform , erythema dyschromicum perstans like , vulvitis and oral fde . a 42-year - old man presented to our dermatology clinic with painful blistering eruption affecting the acral sites and lips . the day before , he had taken paracetamol , ciprofloxacin , and metronidazole from local pharmacy for tooth ache . within 3 h of ingestion of the drugs a few hours later he developed bullae over these sites and erosions on the lips . his medical records revealed a similar episode 10 months back , which developed a day after taking paracetamol over the same sites . he had received ciprofloxacin for urinary tract infection as an inpatient in 2006 without any adverse reaction . cutaneous examination revealed multiple bullae , a few with prominent hemorrhagic component were noted on the dorsa of hands with erythema near the thenar eminence [ figure 1 ] . on histopathological examination , the epidermis revealed foci of basal cell vacuolation , lymphocytic exocytosis , and many necrotic keratinocytes at and above the basal layer . there was also an intraepidermal to subepidermal bulla displaying marked hemorrhage and many neutrophils , a few eosinophils and lymphocytes within its lumen . there was superficial dermal edema and moderate perivascular infiltrates of lymphocytes , histiocytes , neutrophils , and eosinophils . laboratory investigations revealed total white blood cell count 13,200/cu mm with absolute eosinophil count of 160/cu mm . the patient was treated with topical steroid - antibacterial preparation for 1 week . on follow - up , he was counseled to avoid paracetamol in future and to carry a drug alert card . ( a - c ) multiple bullae , a few with prominent hemorrhagic component , were noted on the dorsa of hands ( d ) erosions and crusting on the lips ( a ) intraepidermal to subepidermal hemorrhagic blister with adjacent epidermis showing occasional necrotic keratinocytes ( 200 ) . ( b ) epidermis with necrotic keratinocytes , basal cell vacuolation , and lichenoid infiltrate seen in the superficial dermis ( 40 ) paracetamol is a commonly used nonsteroidal anti - inflammatory drug with a reliable safety profile . systemic manifestations have also been described in patients with fde , though they are very rare . in our patient , the temporal correlation with the drug , history of a similar episode and the quick improvement led us to a diagnosis of bullous fde due to paracetamol . applying naranjo 's algorithm , a causality score of 8 was obtained and was categorized as probable reaction to paracetamol [ table 1 ] . naranjo adverse drug reaction probability scale in appropriate clinical settings , other differentials to bullous fde include blistering disorders , bullous lupus erythematosus , linear iga bullous dermatosis and bullous pemphigoid . fdes may exhibit anatomical preferences to genitalia , lips , and sacrum . in some patients fde could be a result of cross - sensitivity if the drugs are closely related , however it does not follow an all or none reaction . a repeat exposure at times may not result in fde owing to refractoriness , and it could vary from weeks to months . oral rechallenge is the most reliable technique of identifying the causal agent but can be potentially disastrous . a positive patch test over the previously affected area is a relatively safe method . lymphocyte transformation tests useful in many types of drug eruptions yield poor results in cases of fde . clinicians should have a high index of suspicion and should be vigilant of the possible adverse reactions to drugs with robust safety profiles . identification of the offending drug becomes even more challenging in scenarios when the patient is on multiple drug therapy . we report this case to draw attention to a rare side effect of paracetamol , one of the most common over the counter drug . clinicians should have a high index of suspicion and should be vigilant of the possible adverse reactions to drugs with robust safety profiles . identification of the offending drug becomes even more challenging in scenarios when the patient is on multiple drug therapy . we report this case to draw attention to a rare side effect of paracetamol , one of the most common over the counter drug . clinicians should have a high index of suspicion and should be vigilant of the possible adverse reactions to drugs with robust safety profiles . identification of the offending drug becomes even more challenging in scenarios when the patient is on multiple drug therapy . we report this case to draw attention to a rare side effect of paracetamol , one of the most common over the counter drug .
we report a case of a 42-year - old male who presented with second episode of bullous eruptions after ingestion of paracetamol . there were no systemic complaints . 
 the temporal correlation with the drug , history of a similar episode and the quick improvement led us to a diagnosis of bullous fixed drug due to paracetamol . applying naranjo 's algorithm , 
 a causality score of 8 was obtained and was categorized as probable reaction to paracetamol . 
 clinicians should be vigilant of the possible adverse reactions to drugs with robust safety profiles . 
 drug alert cards could play an important role in preventing recurrences .