Diagnosing this severe illness is often difficult because of how slowly it tends to develop. The first signs of Stevens-Johnson Syndrome generally do not develop until about two to three weeks after being exposed to the inciting factor. However, many other medications have uncommonly been reported as being a cause. In addition, certain infections have also been implicated in causing Stevens-Johnson although this is often difficult to prove since most of these children were also using medications to combat the infection, medications that may have been the cause itself. The initial symptom is usually a distinctive rash that develops over the body.
Many benign rashes occur during viral illnesses and mild allergic reactions.
The difference between these and Stevens-Johnson is that the mucous membranes begin to become involved causing ulcerations within the mouth and eyelids. The rash over the skin also progresses to develop blisters sometimes severe enough to be the equivalent of third-degree burns. Because of this, many children who have severe enough symptoms from Stevens-Johnson are transferred to the Burn Unit since treatment of the skin, eyes, and mucous membranes is similar to that of burn victims. I am very sorry to hear that your son has developed this illness. In addition, he will probably receive medications to help calm down his immune system and stop the progression of skin and mucous membrane destruction.