Epidemiology

• Prevalence: accounts for about 80% of cases of contact dermatitis
• Association with Atopy: increased

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Etiology

Acids

• Hydrochloric Acid (HCl) (see Hydrochloric Acid, [[Hydrochloric Acid]])

Alkalis

• Ammonia (see Ammonia, [[Ammonia]])
• Bleach (see Chlorine, [[Chlorine]])
• Detergent
• Drain Cleaners
• Lye
• Oven Cleaners
• Soaps
• Toilet Bowel Cleaners

Bromine/Chlorine(see Chlorine, [[Chlorine]])

• xxx

Hydrocarbons (see Hydrocarbons, [[Hydrocarbons]])

• Cutting Oils
• Lubricating Oils
• Petroleum

Other Chemicals

• Creosote: acts as a contact irritant, sensitizer, and photosensitizer
• Asphalt/Tar Products

Spurge Plants

• General Comments: produce irritating white milky sap
• Candelabra Cactus
• Euphorbia Milii (Crown of Thorns, Christ Plant, Christ Thorn) (see Euphorbia Milii, [[Euphorbia Milii]])
• Euphorbia Pulcherrima (Poinsettia) (see Euphorbia Pulcherrima, [[Euphorbia Pulcherrima]])
• Euphorbia Tirucalli (Firestick, Pencil Cactus, Pencil Tree, Aveloz, Indian Tree Spurge, Naked Lady, Sticks on Fire, Milk Bush) (see Euphorbia Tirucalli, [[Euphorbia Tirucalli]])
• Poinsettia (see Poinsettia, [[Poinsettia]])

Calcium Oxalate-Containing Plants

• Dieffenbachia
• Daffodil
• Hyacinth
• Pineapple

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Physiology

• Mechanism: direct injury to keratinocytes of the skin -> non-immune mechanism
  • Sensitization is not required
  • Involves the innate immune system
  • Concentration of Agent: more critical to pathogenesis of irritant contact dermatitis than in allergic contact dermatitis

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Diagnosis

• Patch Testing: negative
• Skin Biopsy: typically nonspecific

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Clinical Manifestations

• Latency of Reaction After Contact: usually within 48 hrs
• Geographic Pattern
  • Typically sharply demarcated and limited to the contact site
• Variable Presentation: may present as any of the following
  • Mild Dryness
  • Erythroderma (see Erythroderma, [[Erythroderma]])
  • Maculopapular Eruption (see Exanthems, [[Exanthems]] and Papular-Nodular Skin Lesions, [[Papular-Nodular Skin Lesions]])
  • Eczematous Dermatitis
  • Caustic Burn with Bullae and/or Blisters (see Vesicular-Bullous Skin Lesions, [[Vesicular-Bullous Skin Lesions]])
• Other Clinical Features
  • Although may be pruritic, irritant dermatitis is typically has burning or “prickling” pain
  • Cumulative irritant dermatitis most commonly affects thin exposed skin regions (back of hands, between fingers, face, eyelids): long-term exposure may result in pruritus, folliculitis, calcifications, or acneiform rash
  • Melanoderma: may occur with creosote or asphalt/tar products

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Treatment

• Latency to Resolution: typically diminishes spontaneously within 96 hrs

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References

• Contact urticaria due to the common stinging nettle (Urtica dioica)–histological, ultrastructural and pharmacological studies. Clin Exp Dermatol. 1991 Jan;16(1):1-7
• Compositae dermatitis. Australas J Dermatol. 1999 Aug;40(3):123-8 [MEDLINE]
• Long-term safety and toxicity of azathioprine in patients with air-borne contact dermatitis. Indian J Dermatol Venereol Leprol. 2001 Mar-Apr;67(2):75-7 [MEDLINE]
• Contact allergy to herbal teas derived from Asteraceae plants. Contact Dermatitis. 2006 Apr;54(4):196-201 [MEDLINE]
• Compositae dermatitis from airborne parthenolide. Br J Dermatol. 2007 Mar;156(3):510-5
• A systematic approach to systemic contact dermatitis and symmetric drug-related intertriginous and flexural exanthema (SDRIFE): a closer look at these conditions and an approach to intertriginous eruptions. Am J Clin Dermatol. 2011 Jun 1;12(3):171-80 [MEDLINE]