Allergic reactions to drugs

Rashes due to drugs may be relatively mild such as erosions like canker sores, erythema papula, urticarial rashes, and fixed drug eruption, or they may be quite severe as with Stevens-Johnson syndrome or toxic epidermal necrolysis (Lyell syndrome). Since severe drug eruptions and rashes can affect internal organs in addition to skin and mucosa and can result in permanent disabilities, they must be diagnosed and treated as soon as possible. The vital elements of effective diagnosis are to clearly grasp which types of reactions are the most severe and to quickly identify the reactions which may become serious or threatening. We have found in our own practice that the most serious types of drug erosions and rashes are those that affect the whole body. There is a possibility that a very serious case may develop if an erosion of the oral mucosa spreads out beyond the region of the lip where the mucosa changes to skin or if erythema of the epidermis quickly spreads and red spots grow together over a relatively large area. The treatment is to immediately stop taking all suspect drugs and begin a rigorous course of steroids.