Toxic epidermal necrolysis allergic drug reaction

Allergic skin reactions occur in 1-2% of patients who take nitrofurantoin and comprise about 21% of all adverse reactions to nitrofurantoin (5,71). They often occur with other reactions, such as drug fever, lung, or hver reactions. The lesions can present as pruritus, as macular, maculopapular, or vesicular rashes, urticaria, angioedema, or erjdhema multiforme (72). The frequency of serious cutaneous reactions (erythema multiforme, Stevens-Johnson syndrome, or toxic epidermal necrolysis) after nitrofurantoin has been estimated to be 7 cases per 100 000 exposed individuals (71). 

Several types of adverse drug reactions do not easily fit into Cell and Coomb s classification scheme. These include most cutaneous hypersensitivity reactions (such as toxic epidermal necrolysis), immune-allergic hepatitis and hypersensitivity pneumonitis. Another difficulty is that allergic drug reactions can occur via more than one mechanism picryl chloride in mice induces both type 1 and type IV responses. Although other classification schemes have been proposed. Cell and Coomb s system remains the most widely utilized scheme [4-7]. 

---