Diagnosis of the poisoned patient can often be accomplished before toxicologic laboratory tests by obtaining a detailed history and directed physical exam. In this second of three articles, we will examine the toxicology clues revealed by the skin. Part 1 dealt with clues found in eyes, hair, nails, and tongue, and Part 3 will be on body fluids including saliva, sweat, urine, breath, vomit, and stool.

Skin

Hyperkeratoses

  • Arsenic

Arsenic-related Cancers

  • Bowen’s Disease (intraepithelial carcinoma in situ)
  • Basal cell carcinoma
  • Internal malignancies (lung, liver, esophagus, bladder)

Skin Color Changes (usually hyperpigmentation)

  1. Increased melanin production or deposition of abnormal pigment
    • “Raindrops on a Dusty Road” (As)
    • Addison’s Disease (tan, esp scars and flexion creases)
    • Melanosis (metastatic malignant melanoma)
  2. Differential diagnosis of “Gray Man” (slate gray, blue-gray, slate-blue)
    • Ag (Argyria), Hg, Bi, Pb, As, Au (Chrysiasis) intoxication
    • Amiodarone (more marked on sun-exposed skin)
    • Chemotherapy (fluorouracil)
    • Ochronosis (gray to brown external ears, sclerae)
  3. Red Man Syndromes (usually 2º vasodilation)
    • Redness non-pigmentary, usually blanches
    • Rapid infusion of vancomycin, NAC
      • Flushing from histamine release
    • Borate poisoning (“red lobster”)
    • Degreaser’s Flush (TCE + alcohol)
    • Disulfiram reaction
      • alcohol + metronidazole, sometimes cefazolin
      • alcohol + coprine mushrooms (“Tippler’s Bane)
    • Diff’l Dx of erythroderma: Toxic Shock Syndrome
  4. Blue Man Syndromes
    • Cyanosis
    • Methemoglobinemia
      • aniline dyes, nitrites, local anesthetics (benzocaine)
      • unlike jaundice, sclerae remain white!
    • Pseudocyanosis (faux bleu)
      • Skin staining by fabric dye
  5. Toxic jaundice
    • Hepatotoxins
      • Jaundice is late sign, delayed by days after intoxication
      • Acetaminophen, Amanita and Lepiota mushrooms
    • Hemolytic toxins (often oxidizing agents that also cause methemoglobinemia, esp in patients with G6P deficiency)
      • chlorates, dapsone
      • gases: arsine, stibine
      • Loxosceles (brown recluse) envenomation, esp in children
  6. Other cutaneous discoloration syndromes
    • Hemochromatosis (bronze hyperpigmentation)
    • Carotenemia (sclerae remain white)
    • Skin and clothing stains from paint and glue-sniffing
      • gold and silver most common

Pressure lesions (narcotics and sedative-hypnotics)

  1. Redness
    • early bruising or pressure lesion
    • persists > 20 minutes after pressure relieved
    • failure to blanche on pressure distinguishes from flushing
    • 2º pressure-induced epidermal ischemia, but lesions also form on non-dependent skin
  2. Imprints
    • pattern ecchymoses from objects lain upon
  3. Bullous (“Coma Bullae”)
    • Barbiturates
    • Benzodiazepines
    • Carbon monoxide
  4. Any pressure lesion: check for myoglobinuria and rhabdomyolysis

Vesiculobullous Lesions

  1. Mustard gas
  2. Sulfuric and other acids
  3. Antibiotics, ACEI’s
  4. Caterpillars (Puss caterpillar of Texas; tarantulas (urticating hairs)
  5. Pemphigus, bullous pemphigoid
  6. Poison Ivy (also maculopapular)

Desquamation/Exfoliation

  1. Barbiturates, borates, methadone, colchicine
  2. Toxic Epidermal Necrolysis (antibiotics), Stevens-Johnson Syndrome
  3. Non-Toxic Dffl Dx of Desquamation: Toxic Shock, Kawasaki’s Disease, Staphylococcal Scalded Skin Syndrome

Petechiae, purpura, hematomas

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