steven johnson syndrome ( sjs ) is characterized by sudden onset of erosion of mucous membranes ( predominantly oral mucosa , lips , and conjunctivae ) with widespread blistering of the skin involving up to 10% of the body surface area .
trimethoprim - sulfamethoxazole ( tmp / smx ) is a widely prescribed antimicrobial for the management of several uncomplicated infections . in immunocompetent persons , the adverse reactions to
tmp / smx occur in approximately 1 - 3% of persons . in contrast , in hiv - infected population
, a much higher incidence of adverse reactions has been reported with frequencies ranging from 40 - 80% .
we report a hiv - infected man who developed sjs while receiving tmp / smx therapy .
a 33-year - old male presented with complaints of intermittent low grade fever for two months , cough with expectoration for one and half month , loss of weight , and appetite for one month .
the patient was afebrile with a pulse rate of 92/min , respiratory rate of 30/min and blood pressure of 120/70 mmhg .
investigations revealed : hemoglobin 9.2 gm / dl , total leucocyte count 7500/cumm with an absolute lymphocyte count of 1500/cumm , platelet count of 2.1 lac / cumm and erythrocyte sedimentation rate of 76 mm at the end of 1 hr .
hiv - elisa was positive . in view of the clinical presentation and investigations , a diagnosis of pneumocystis jirovecii pneumonia ( pcp )
was considered and the patient was started on tmp / smx doubles strength two tablets thrice daily .
after ten days of starting tmx / smx therapy , the patient developed high grade fever , redness and pricking sensation in eyes , and burning sensation in throat . within the next 48 hours he developed blepharitis , conjunctival congestion , erythema of the eyelids , and oral mucosal erosions [ figure 1 ] .
painful , erythematous , maculopapular , and vesicular lesions appeared all over the body including genitals [ figure 2 ] .
there were multiple ulcerations in the buccal mucosa , floor of the mouth , and ventral surface of the tongue .
the patient was hemodynamically stable with a pulse rate of 102 per / min and a blood pressure of 110/80 mmhg .
the alanine aminotransferase and aspartate aminotransferase levels were 250u / l ( 10 - 40u / l ) and 155u / l ( 10 - 35u / l ) , respectively .
the patient was treated aggressively with intravenous dexamethasone 6 hourly , intravenous fluids , prophylactic antibiotics , anti - allergic drugs and local treatment of lesions .
re - epithelialization of the previously sloughed areas occurred and the general condition of the patient remained satisfactory .
he was discharged after a month by which time the skin had healed with post - inflammatory hypopigmentation .
desensitization to tmp / smx was not attempted and the patient was discharged on dapsone prophylaxis for pcp .
clinical photograph showing conjunctival congestion , erythema of the eyelids , and blepharitis clinical photograph showing cutaneous lesions all over the body with oral mucosal erosions
tmp / smx is commonly used for the treatment and prophylaxis of pneumocystis jirovecii pneumonia ( pcp ) in hiv - infected patients . in addition to its efficacy in preventing pcp , tmp /
however , the administration of tmp / smx is hampered by the high incidence of hypersensitivity reactions in these patients .
the most common adverse reactions include nausea , vomiting , anorexia , dermatological reactions such as pruritis , urticaria and less commonly steven johnson syndrome ( sjs ) , neutropenia , exfoliative dermatitis , erythema multiforme and toxic epidermal necrolysis . a pubmed search using the keywords
 trimethoprim - sulfamethoxazole and  steven johnson syndrome and  human immunodeficiency virus revealed less than ten cases being reported in literature till date .
the increased incidence of adverse reactions to tmp / smx in hiv - infected patients is due to the hydroxylamine derivative of sulphamethaxazole , i.e. , sulphamethaxazole hydroxylamine .
the deficiency of glutathione enzyme in hiv - infected patients results in a decreased capacity to scavenge these hydroxylamine derivatives . in vitro
, it has been found that as compared to cd8 cells , purified cd4 cells are more resistant to the sulphamethaxazole hydroxylamine . in hiv infection
, the depletion of cd4 cells leaves a greater proportion of circulating t - cells as the more susceptible cd8 subset .
in addition , the immune dysfunction observed in hiv - infected patients , i.e. , the polyclonal b - cell activation , polyclonal gammopathy , and decreased t - suppressor cell functions leads to an exaggerated humoral immune response to smx or its metabolites .
other factors such as viral load and concurrent medications may also increase cell sensitivity to reactive metabolites .
it is not clear whether the adverse reactions to tmp / smx merely indicate or also induce progression of hiv disease .
veenstra et al . found that patients with adverse reactions to tmp / smx have a more rapid decline in cd4 cell counts and rapid progression to aids and death . in patients with non life - threatening adverse reactions ( e.g. , fever , rash ) , rapid or slow oral desensitization to tmp / smx
can be attempted . however , in patients with severe life threatening adverse reaction to tmp / smx , alternative drug like dapsone , pentamidine , or atovaquone should be given for pcp prophylaxis .
those who do not tolerate or have recurrent pcp infections despite alternative therapy could be subjected to a trial of desensitization to tmp - smx under close supervision .
this case illustrates a clinically important and life threatening adverse effect of tmp / smx in hiv - infected patients . due to the high incidence of such hypersensitivity reactions
 trimethoprim - sulfamethoxazole ( tmp / smx ) is a widely prescribed antimicrobial for the management of several uncomplicated infections . 
 it is commonly used for the treatment and prophylaxis of pneumocystis jirovecii pneumonia ( pcp ) in the hiv - infected population . 
 the adverse reaction to tmp / smx is more frequent and severe in hiv - infected patients as compared to the general population . here 
 , we report a case of stevens - johnson syndrome ( sjs ) secondary to tmp / smx . 
 the patient had a generalized cutaneous reaction with involvement of the eyes , oral cavity , and genitals . 
 he had elevated hepatic alanine aminotransferase and aspartate aminotransferase enzyme . 
 tmp / smx therapy was stopped and supportive treatment was started . 
 his condition improved after eight days of stopping tmp / smx therapy . 