Skin nontumor

Lichenoid and interface reaction patterns

Drug reactions

Last author update: 1 July 2011
Last staff update: 28 April 2023

Copyright: 2002-2023,, Inc.

PubMed Search: Drug reaction skin

Mowafak Hamodat, M.B.Ch.B., M.Sc.
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Cite this page: Hamodat M. Drug reactions. website. Accessed October 2nd, 2023.
Fixed drug reaction
Definition / general
  • May cause urticaria, erythema multiforme, erythema nodosum, folliculitis, pustules, purpura, hyperpigmentation or vasculitis
  • Procainamide may induce SLE-like disease
  • Anti-cancer drugs may cause acute necrotizing changes in sweat glands (neutrophilic eccrine hidradenitis or syringosquamous metaplasia)
  • Drug induced coma may cause necrosis of eccrine sweat coils and other adnexae, also epidermis
  • Other drugs causing cutaneous reactions include gold salts, thiazides, antimalarial drugs, color film developers, tetracycline, barbiturates, phenolphthalein
  • Fixed drug reaction: repeated administration causes recurrence of red-brown patch in same location, variable bullae

  • Genitalia and face

  • Discontinue drug

Clinical images

Contributed by Mark R. Wick, M.D.

Breast skin

Images hosted on other servers:

14 year old boy with reaction to sulfasalazine

Microscopic (histologic) description
  • Eosinophils and marked vascular wall thickening
  • May cause granulomatous infiltrate
  • Also vacuolar interface changes and often lymphocytic exocytosis, dyskeratotic keratinocytes, parakeratosis with eosinophils and plasma cells in dermis

Microscopic (histologic) images

Contributed by Mark R. Wick, M.D.

Breast skin

Differential diagnosis

Additional references
Interstitial granulomatous drug reaction
Definition / general
  • Reaction due to beta blockers, calcium channel blockers, lipid lowering agents, ACE inhibitors, diuretics, NSAIDs, antihistamines, antidepressants and oral hypoglycemic agents; often more than one of the above
  • Mean duration of 5 years before onset of eruptions
  • Resolves a mean 8 weeks (range 1 - 40) after drug is stopped
  • May be due to exaggerated immune response to drugs

Clinical features
  • Violaceous to erythematous, nonpruritic plaques with bizarre shapes or annular morphology on skin folds (axilla, inner arms, groin, medial thighs and popliteal fossa)

Case reports

Microscopic (histologic) description
  • Diffuse granulomatous dermatitis with interstitial histiocytes and giant cells near collagen and elastic fibers, often with piecemeal fragmentation of collagen, giant cell engulfment of elastic fibers and variable interstitial mucin (J Cutan Pathol 1998;25:72)
  • Usually interface dermatitis with basilar vacuolopathy and focal dyskeratosis with lymphocytes at dermoepidermal junction
  • Usually tissue eosinophilia, lymphoid atypia with hyperchromatic nuclei, convoluted nuclear contours (including a few cerebriform nuclei in dermis), variable involvement of hair follicles and acrosyringia
  • Rare collagen necrobiosis
  • Usually no fibrin deposition within vessels or vasculitis

Differential diagnosis
Morbiliform drug reaction (pending)
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