Cutaneous Adverse Drug Reactions / Dematološka neželjena dejstva lekova

Adverse drug reactions may be defined as undesirable clinical manifestations resulting from administration of a particular drug; this includes reactions due to overdose, predictable side effects, and unanticipated adverse manifestations. Adverse drug effects on the skin are among the most frequent reactions and, according to a study, account for approximately 14% of all adverse drug reactions. However, the incidence of cutaneous adverse effects in general population is unknown. Systemic drug administration results in various cutaneous adverse reactions, and medications used in the treatment of skin diseases themselves have their own adverse effects. Adverse drug reactions include a wide range of effects, from harmless exanthema of short duration, urticaria to systemic cutaneous reactions such as drug rash with eosinophilia and systemic symptoms (DRESS) or toxic epidermal necrolysis. Exanthematous eruptions and urticaria are the two most common forms of cutaneous drug reactions. Less common include fixed eruptions, lichenoid, pustular, bullous and vasculitis reactions. The most severe cutaneous and mucosal adverse drug reactions are epidermal necrolysis, which is usually drug-induced, DRESS syndrome, and acute generalized exanthematous pustulosis. Therefore, the diagnostic of adverse drug reactions requires a detailed history of drug intake and development of skin disorders, excellent knowledge of clinical presentations for a wide range of drug-induced skin reactions as well as of the very medications being taken by patients. In addition to details on drug intake, it is necessary to learn about taking herbal and alternative preparations, which may also cause adverse reactions. A drug started within 6 weeks of the development of disorders is considered the most common cause of adverse reaction, as well as drugs taken periodically but regularly. Once a reaction has occurred, it is important to prevent future similar reactions with the same drug or a cross-reacting medication. Early withdrawal of all potentially responsible drugs is essential, particularly in case of severe drug reactions.