Drug eruption

An adverse reaction to a medication manifesting on the skin

Overview

A drug eruption is a type of adverse drug reaction that manifests as a skin condition. These eruptions can vary widely in appearance and severity, ranging from mild rashes to severe, life-threatening conditions. Drug eruptions are a common reason for dermatological consultations and can be caused by a wide variety of medications.

Pathophysiology

Drug eruptions occur when the body's immune system reacts to a medication. This reaction can be mediated by different immunological mechanisms, including IgE-mediated hypersensitivity, T-cell mediated reactions, and immune complex formation. The specific mechanism often determines the type and severity of the eruption.

Types of Drug Eruptions

Exanthematous Eruptions

Exanthematous eruptions, also known as maculopapular rashes, are the most common type of drug eruption. They typically appear as widespread red spots and bumps on the skin and are usually symmetrical. These eruptions are often benign and resolve after discontinuation of the offending drug.

Urticarial Eruptions

Urticaria, or hives, are raised, itchy welts on the skin that can be caused by drug reactions. These eruptions are often associated with IgE-mediated hypersensitivity and can occur rapidly after drug exposure.

Fixed Drug Eruptions

A fixed drug eruption is characterized by a well-defined, round or oval patch that recurs at the same site each time the drug is taken. These lesions can be red, purple, or brown and may blister.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe, life-threatening drug eruptions. They involve widespread skin detachment and mucous membrane involvement. These conditions require immediate medical attention and often hospitalization.

Diagnosis

The diagnosis of a drug eruption is primarily clinical, based on the patient's history and the appearance of the skin lesions. A detailed medication history is crucial, including over-the-counter drugs and supplements. In some cases, skin biopsy or patch testing may be used to confirm the diagnosis.

Management

The primary treatment for drug eruptions is the discontinuation of the offending medication. Supportive care, such as antihistamines for itching or corticosteroids for inflammation, may be provided. In severe cases, such as SJS or TEN, hospitalization and intensive care may be necessary.

Prevention

Preventing drug eruptions involves careful prescribing practices, including reviewing patient allergies and previous drug reactions. Patients should be educated about the potential for drug eruptions and advised to report any new skin changes promptly.

Related pages

• Adverse drug reaction
• Hypersensitivity
• Dermatology

A typical drug eruption rash on the skin.