Irritant Contact Dermatitis

• Irritant contact dermatitis is a non-immune inflammatory reaction caused by direct skin barrier damage from chemical, physical, or mechanical irritants
• May be acute following intense exposure or chronic following repeated exposure to weaker

irritants

• Severity depends on irritant concentration, duration and frequency of exposure, and integrity of the skin barrier
• Unlike allergic contact dermatitis, prior sensitization is not required
• Usually predominantly confined to areas directly exposed to the irritant
• Accounts for the majority of occupational contact dermatitis, especially in healthcare, hairdressing, cleaning, food service, construction, mechanics, and horticulture
• Predisposing factors include atopic dermatitis, wet work, cold/dry climates, occlusion, and friction

• Acute form: develops rapidly or within several hours of significant irritant exposure. Burning or stinging often predominates, with possible pain and variable pruritus
• Chronic form: develops gradually after repeated exposure to water, soaps, detergents, or solvents. Dry, rough skin with burning or stinging, variable pruritus, and potentially painful fissures

• Acute form:

 • Usually well-demarcated erythema corresponding to the exposed area

 • Possible edema

 • Vesicles, bullae, or erosions with more intense reactions

 • Crusting and scaling during resolution

 • Necrosis or ulceration may occur following severe caustic exposure

• Chronic form:

 • Xerosis

 • Erythema

 • Scaling and hyperkeratosis

 • Fissures and chapping

 • Lichenification may develop with chronic disease

• Distribution generally corresponds to areas directly exposed to the irritant
• The hands are the most commonly affected site, particularly in occupational dermatitis
• Face and neck may be involved with airborne irritants
• Unlike allergic contact dermatitis, spread beyond the areas of contact is generally limited

• Dermoscopy is generally not required for diagnosis

• Diagnosis is primarily clinical
• Based on:

 • Compatible morphology

 • Distribution corresponding to exposure

 • Temporal relationship with a potential irritant

 • Relevant occupational and household exposures

 • Improvement following avoidance of the causative agent

• No specific laboratory test confirms irritant contact dermatitis
• Skin biopsy is rarely required and is reserved for atypical or diagnostically uncertain cases

• Allergic contact dermatitis
• Atopic dermatitis
• Psoriasis, particularly palmoplantar psoriasis
• Dermatophytosis (tinea manuum/pedis)
• Dyshidrotic eczema
• Seborrheic dermatitis depending on location
• Photoallergic or phototoxic contact dermatitis when photodistributed

Avoidance and protection (cornerstone of treatment)

 • Identify / avoid / minimize exposure to the causative irritant

 • Use protective equipment depending on exposure

 • Reduce wet work, repeated washing, detergents, and other irritants whenever possible

Restore the skin barrier

 • Apply thick, fragrance-free emollients several times daily

 • Use gentle fragrance-free cleansers

 • Barrier/protective creams may be useful depending on exposure

Active inflammation

 • Topical corticosteroid for the affected site and severity for a short course

 • Example for thick hand dermatitis: clobetasol propionate 0.05% 1-2x/day for approximately 7-14 days, followed by reassessment

 • Avoid superpotent corticosteroids on the face, flexures, and thin skin

Specificities :

• Wet compresses may be useful for acute weeping or vesiculobullous disease
• Chronic/refractory disease: reassess ongoing exposures and investigate possible concomitant allergic contact dermatitis; phototherapy or other specialist therapies may be considered
• Caustic chemical exposure causing burns, ulceration, or necrosis requires immediate decontamination and appropriate urgent medical management