contact%20dermatitis
CONTACT DERMATITIS
Treatment Guideline Chart

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.

Contact%20dermatitis Signs and Symptoms

Definition

  • Any skin disorder brought about by contact with an exogenous substance that triggers an allergic and/or irritant response

Signs and Symptoms

Allergic Contact Dermatitis
  • Initially, lesions appear on the cutaneous site of principal exposure; may spread to other more distant sites due to contact or autosensitization
  • Lesions are typically asymmetrical, ill-defined and unilateral
  • Specific signs and symptoms will depend on the duration, location, degree of sensitivity and concentration of allergens
  • Patch test shows reaction to allergen
Acute Allergic Contact Dermatitis
  • Acute eruptions present with macular erythema, papules, vesicles and bullae
Chronic Allergic Dermatitis
  • Lesions are usually lichenified, scaling, fissures with or without vesicles
  • Pigmentary changes can occur

Other Types of ACD

  • Airborne contact dermatitis is caused by an airborne transmission of contact allergen commonly seen in the face and neckline
  • Hematogenous contact dermatitis is a special form of ACD which is triggered after epicutaneous sensitization to allergens and commonly seen in the intertriginous areas and gluteal regions
  • Photoallergic contact dermatitis is triggered by combined exposure to photosensitizers and ultraviolet (UV) light
  • Phototoxic contact dermatitis is seen in sun-exposed skin and lesions with well-defined border
  • Protein contact dermatitis is a less common type caused by immunoglobulin E (IgE)-mediated allergy
Irritant Contact Dermatitis
  • Prone to irritation from chemical substances are the face, dorsum of the hands, finger webs, palms, soles or back
  • Lesions are usually sharply defined at contact sites
Acute Irritant Contact Dermatitis
  • Acute lesions are painful, edematous, erythematous, weepy and vesicular
  • There is associated sensation of burning, stinging or pain in the site of contact to irritant
  • Usually results from a single exposure to an irritant or caustic chemical
Chronic Irritant Contact Dermatitis
  • Chronic lesions are dry, erythematous, scaling, fissuring, cracked and lichenified
  • Hardening and adaptation of the skin may occur due to repeated contact with irritants

Risk Factors


Common Trigger Factors

  • Allergic Contact Dermatitis
    • Medications, certain plants, metals, foods, fragrances, stabilizers in skin products, preservatives, etc 
  • Irritant Contact Dermatitis
    • Strong alkaline soaps, organic solvents, acid, chlorinated or bleach type ingredients, inhalants, airborne chemicals, etc

Location of inflammation may suggest trigger factors for Allergic Contact Dermatitis and Irritant Contact Dermatitis

  • Eg scalp and ears
    • Possible trigger factors: Shampoo, hair dyes, topical medication, spectacles, metal earrings, etc

Allergic Contact Dermatitis and Irritant Contact Dermatitis may be related to occupational exposure

  • Exposure to cement, epoxy, glues, paint and solvents may trigger allergic contact dermatitis
  • Fuels, lubricants and cement may trigger irritant contact dermatitis
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