contact%20dermatitis
CONTACT DERMATITIS

Contact dermatitis is an inflammation of the skin that can be acute or chronic that manifests as eczematous dermatitis due to exposure to substances in the environment.

Allergic contact dermatitis is an immunologic cell-mediated skin reaction to exposure to antigenic substances.
The lesions initially appear on the cutaneous site of principal exposure then may spread to other more distant sites due to contact or autosensitization. Lesions are typically asymmetrical and unilateral.
Specific signs and symptoms will depend on the duration, location, degree of sensitivity and concentration of allergens. The patch test shows reaction to allergen.
Irritant contact dermatitis is a non-immunologic skin reaction to skin irritants.
It is often localized to areas of thin skin eg eyelids, intertriginous areas.

Pharmacotherapy

Allergic Contact Dermatitis

Corticosteroids (Topical/Oral)

  • Anti-inflammatory & immunosuppressing effects by decreasing the production of cytokines & stopping lymphocyte production
  • Topical corticosteroids
    • Usually effective for most cases of ACD
    • Moderate potency products are usually sufficient for acute dermatitis
    • High potency products may be required for persistent dermatitis or chronic dermatitis
  • Oral corticosteroids
    • Recommended in patients who have >10-25% of their body surface area (BSA) affected or if they have been exposed to allergens that cause symptoms to persist
    • Rapid symptomatic relief of ACD

Antihistamines (Oral)

  • Help to relieve pruritus
    • If sedating antihistamine is used, it will help the patient to sleep through the night

Others

  • Antibiotics1 (topical/oral)
    • May be needed in cases of secondary infection

Irritant Contact Dermatitis

Corticosteroids (Topical)

  • Moderate potency products are usually sufficient for acute dermatitis
  • High potency products may be required for persistent dermatitis or chronic dermatitis

Antihistamines (Oral)

  • Help to relieve pruritus
    • If sedating antihistamine is used, it will help the patient to sleep through the night

Others

  • Antibiotics1 (topical/oral)
  • May be needed in cases of secondary infection



1
Various products are available. Please see prescribing information for specific formulations in the latest MIMS.

Non-Pharmacological Therapy

Identify & Eliminate Trigger Factors

  • ACD: Patient should avoid allergens & all cross-reactants completely
    • Counsel patient regarding cross-reactants (eg patient w/ Lidocaine allergy should avoid all local anesthetic of the amide type)
  • If dermatitis is due to occupational exposure:
    • Personal protection eg protective gloves, clothing
    • Workplace protection
    • Advice on choice of career in person w/ known allergy

Skin Care

  • Bathe affected areas using mild soap & lukewarm water
    • Oatmeal products added to bath may also relieve symptoms

Acute Dermatitis

Wet Dressings

  • Apply absorbent material dressings soaked in Al acetate to affected areas several times daily
  • Relieves symptoms & speeds healing of weeping lesions w/ exudates by gentle debridement, debris removal & evaporated cooling

Chronic Dermatitis

Emollients

  • Should be applied frequently, esp after contact w/ water or irritants
  • Provide an occlusive layer over inflamed skin, reduce evaporation & decrease fissuring
  • Patient preference & treatment area will determine formula used
    • Eg petrolatum, liquid paraffin, mineral oils, glycerine, etc
    • Avoid products w/ high water content, preservatives or fragrances

Severe Chronic Allergic Contact Dermatitis

Phototherapy

  • Narrow-band UVB or PUVA may be used in patients w/ severe chronic ACD
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