Rovner

REACTIVE ERYTHEMAS

1. Urticaria, Angioedema Type I hypersensitivity

   Red wheals, plaques with central translucency; pruritic!

   Lesions recur in crops and waves, each lasting under 24 hours

   Acute--under 6 weeks

   Chronic--over 6 weeks

   1. Types:
      1. Angio[neurotic]edema--swelling of lips, genitalia, eyelids
      2. Contact--rare; DMSO, cinnamates
      3. Papular--insect bite reaction
      4. Dermographism
      5. Hereditary Angioedema--complement mediated
   2. Etiology
      1. Drugs--antibiotics (PCN, sulfa), salicylates
      2. Foods--shellfish, tartrazine dyes
      3. Physical Factors--heat, cold, pressure
      4. Stress
   3. Treatment--antihistamines
      1. Steroids
      2. epinephrine
2. Erythema Multiforme

1. Etiology

1. Infectious--Herpes virus, mycoplasma, deep fungi
2. Drugs-- -phenobarbital, PCN, sulfa

1. Treatment--self limited
   0. ? steroids
   1. antihistamines
   2. treat underlying condition
2. Variants
   0. Steven's Johnson Syndrome
      1. Erythema multiforme with bullous, erosive lesions
      2. Mucosal involvement
      3. Severe, potentially life threatening
   1. Toxic Epidermal Necrolysis
      1. Widespread denudation, sloughing of inflamed skin
      2. Mortality--over 50%!?

1. Erythema Nodosum (panniculitis)
   1. painful subcutaneous nodules on anterior shins, bilaterally
   2. bruising with pink/yellow/purple shiny plaques or nodules
   3. NO ulceration
   4. Etiology: Infectious (viral, Strep, deep fungi)
   5. Drugs (BCP's, PCN)
   6. Inflammatory Bowel Disease
   7. Sarcoid
   8. Treatment--self limited, lasting up to several weeks
      1. NSAID's
      2. steroids
2. Drug Reactions--Type IV hypersensitivity (except urticaria)
   1. Morbilliform--symmetric, pruritic coalescent pink papules and plaques
      1. typically begins within 1 week of new drug
      2. Bactrim, PCN
   2. Urticaria
   3. "Fixed"--phenolphthalein (Ex-Lax); Tetracyclines
   4. Phototoxic--Tetracyclines, Thorazine, NSAID's
   5. Alopecia--heparin, coumadin
   6. Bullous--griseofulvin, nalidixic acid
   7. Lupus Erythematosus--hydralazine, procainamide, INH
   8. Psoriasis--lithium