Drug induced conditions/Drug eruptions
Common manifestation of adverse reaction to drugs. Occur in up to 2% of hospitalised patients. Many mimic other skin conditions. Diagnosis is difficult, as eruptions are non-specific.
Mechanisms of drug eruptions:
1) Immune mediated:
• Type 1 reaction (IgE binds to mast cells) urticaria (eg penicillin)
• Type 2 reaction (antibodies activate complement) purpura (eg quinidine)
• Type 3 reaction (immune complex deposition) vasculitis (eg penicillin)
• Type 4 reaction (lymphocyte and cytokine mediated) maculopapular, eczematous (eg penicillin)
2) Non-immune mediated:
• binds directly to mast cells release of inflammatory mediators urticaria (eg opiates)
• unwanted mode of action of drug (eg ichthyosis from lipid lowering drugs)
• toxicity from accumulation of drug or metabolites (eg pigmentation from minocycline)
The variety of cutaneous manifestations are wide:
Pruritis, maculopapular reactions, urticaria, angioedema, photosensitvity reactions
Drugs that most commonly produce skin reactions:
amoxicillin; trimethoprim-sulfamethoxazole; ampicillin; ipodate sodium; whole blood; cephalosporins; allopurinol; carbamazepine
We have not yet got to this page. We will eventually. Please contact us if you have something to contribute to it or sign up for our newsletter or like us on Facebook and Instagram or follow us on Twitter. |
Page last updated:
Comments are closed.