Stream 3 Treatment - Common Skin Drug Rashes

Topics to be covered in the Certificate Course.

Common skin drug rashes
Fixed drug reaction
Potentially severe drug reactions

Drug Reactions

It is a sad fact of modern medical practice that many of the drugs that we use cause drug reactions. Around 10% of the patients admitted to hospital will have some reaction due to medication that has been given to them and that sets them back somewhat in their recovery. Some drug reactions are dose related. Again we all vary in the rate at which we absorb and metabolise drugs so the doses that we use are a bit of a hit and miss affair with most people. However when we think of drug reactions in the skin we tend to think of a florid reaction and this holds true for the vast majority of drug reactions in the skin. The only one that is not so florid is the rare one called a fixed drug reaction when only a very small area of the skin may react each time a drug is taken but this is usually a drug that is taken intermittently. We will deal with fixed drug reactions later.

The clinical presentations of drug reactions can mimic just about any disease in medicine. Drug reactions can also exacerbate pre existing diseases, for example psoriasis. Some skin diseases are almost always due to a drug such as lichen planus.

The easiest way to approach drug reactions is to consider a drug cause of virtually every rash that you see and hence know which are the commonest drugs to cause which rash. This is the way in which we will approach it in this module. Remember though that the complexities of drug reactions are many. Drug reactions are not simply allergies but can result from variations in factors such as the way in which drugs are broken down, a patient’s immune status, coexistent viral disease, drug dosage and in features of the drugs themselves that make them more likely to be allergic.