Contact%20dermatitis Signs and Symptoms

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

• 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 eruptions present with macular erythema, papules, vesicles and bullae

• 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

• 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 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 lesions are dry, erythematous, scaling, fissuring, cracked and lichenified
• Hardening and adaptation of the skin may occur due to repeated contact with irritants

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