Contact Dermatitis

Inflammatory ICD: L25

Also known as: Allergic Contact Dermatitis, Irritant Contact Dermatitis

Description

Contact dermatitis is an inflammatory skin reaction caused by direct contact with an external substance. Irritant contact dermatitis (ICD) is more common and results from direct chemical damage, while allergic contact dermatitis (ACD) involves a delayed type IV hypersensitivity reaction. It is one of the most common occupational skin diseases.

Symptoms

  • Erythema and oedema at contact site
  • Vesicles and bullae (acute phase)
  • Pruritus (often intense in ACD)
  • Dryness, fissuring, and scaling (chronic phase)
  • Well-demarcated borders corresponding to contact area
  • Lichenification with chronic exposure

Causes & Triggers

  • Irritants: soaps, detergents, solvents, water (ICD)
  • Allergens: nickel, fragrances, preservatives, rubber (ACD)
  • Cosmetic ingredients (parabens, formaldehyde releasers)
  • Topical medications (neomycin, bacitracin)
  • Occupational exposure (healthcare workers, hairdressers)

Severity Classification

Mild Localised erythema and dryness, minimal vesiculation
Moderate Spreading erythema, vesicles, significant pruritus
Severe Widespread bullous reaction, secondary infection, inability to work

Treatment Ladder

  1. 1 Identification and avoidance of causative agent (most important step)
  2. 2 Mild: Emollients and low-potency topical corticosteroids
  3. 3 Moderate: Medium-to-high-potency topical corticosteroids
  4. 4 Severe / Extensive: Short course of oral prednisolone
  5. 5 Chronic: Steroid-sparing agents (tacrolimus, pimecrolimus)

Relevant Compounds

Allantoin

Skin protectant and soothing agent

Allantoin is a naturally occurring nitrogenous compound found in botanical extracts (particularly co…

Aloe Vera

Anti-inflammatory soothing agent

Aloe vera is derived from the inner gel of Aloe barbadensis miller leaves. It contains over 75 activ…

Ceramides

Barrier repair — restores disrupted lipid barrier

Ceramides are a family of waxy lipid molecules that make up approximately 50% of the lipids in the s…

Hyaluronic Acid

Hydration support for damaged skin

Hyaluronic acid is a naturally occurring glycosaminoglycan found abundantly in the dermis and epider…

Hydrocortisone

First-line low-potency topical steroid for mild cases

Hydrocortisone is a low-potency topical corticosteroid identical to endogenous cortisol. It is the m…

Panthenol

Promotes wound healing and barrier recovery

Panthenol (D-panthenol or dexpanthenol) is the alcohol analogue of pantothenic acid (vitamin B5). Up…

Squalane

Emollient — non-irritating lipid replacement

Squalane is the hydrogenated (saturated) form of squalene, a naturally occurring lipid produced by h…

Recommended Drugs

Cortaid OTC hydrocortisone for acute flares

Suggested Cosmetics

Cetaphil Gentle Skin Cleanser Minimalist formula safe for irritated skin Dot & Key Ceramide & Hyaluronic Acid Moisturiser Gentle ceramide-based moisturiser for damaged barrier Physiogel AI Calming Relief Cream Barrier repair for irritant-damaged skin Re'equil Ceramide & Hyaluronic Acid Moisturiser Ceramide-based barrier repair for damaged skin Venusia Max Intensive Moisturising Cream Barrier-repair emollient for damaged skin

Lifestyle Tips

  • Patch testing is essential for identifying allergens in ACD
  • Use fragrance-free, hypoallergenic skincare products
  • Wear protective gloves for occupational or household chemical exposure
  • Apply emollients frequently to restore and maintain barrier function
  • Keep a contact diary to identify triggering substances

When to Refer

  • Need for patch testing (allergic contact dermatitis suspected)
  • Occupational contact dermatitis (medicolegal implications)
  • Widespread or severe reaction not responding to topicals
  • Secondary infection requiring systemic antibiotics