Clinical Features:

• A variety of drugs can cause a vasculitic reaction, one of the many possible forms of drug reactions.
• Even among drug-induced vasculitides, there are several described patterns, with particular drugs associated with each.  These include: leukocytoclastic vasculitis, Henoch-Schönlein purpura, pustular vasculitis, pigmenary purpura and polyarteritis nodosa-like reactions.
• The prototypical drug associated vasculitis is a leukocytoclastic vasculitis.  The most commonly implicated drugs here are phenylbutazone, indomethacin, allopurinol, penicillins, erythromycin, sulfonamides, thiazide diuretics and hydantoins.
• Leukocytoclastic vasculitis classically presents with palpable purpua on the lower extremities.

Histologic Features:

(This discussion pertains to drug-induced leukocytoclastic vasculitis.)

• Vasculitis confined to the superficial vascular plexus, consisting of fibrinoid degeneration and a predominantly neutrophilic inflammation of the vessel walls, with karyorrhexis ("nuclear dust") of the neutrophil nuclei ("leukocytoclasia")
• Tissue eosinophilia
• Red blood cell extravasation is frequently present.
• The epidermis may be normal or may show necrosis, vesiculation or pustulation.

Cases associated with this book:

Hypersensitivity vasculitis
Author: Stephen Lyle, M.D., Ph.D.

Conference: DermatopathologyConsultations.com Teaching Collection