Review on Managing and Preventing Irritant Contact Dermatitis in Occupational Settings

Introduction

Irritant Contact Dermatitis (ICD) is the most prevalent form of contact dermatitis, notably in occupational settings. It results from skin barrier disruption caused by external agents and environmental factors, which activate innate immune responses. This review consolidates the pathogenesis, risk factors, clinical features, and management strategies for ICD, drawing insights from the works of Patel and Nixon (2022) and Bains, Nash, and Fonacier (2019).

A case of allergic or irritant contact dermatitis caused by unprotected handling of damp construction debris one day earlier

Pathogenesis

ICD occurs due to the direct toxic effects of irritants on epidermal keratinocytes, leading to skin barrier disruption. This damage initiates an inflammatory response involving the release of pro-inflammatory cytokines like IL-1α, IL-1β, TNF-α, GM-CSF, IL-6, and IL-8. These cytokines activate Langerhans cells, dermal dendritic cells, and endothelial cells, leading to further recruitment of neutrophils, lymphocytes, macrophages, and mast cells to the epidermis. Chronic exposure to weak irritants like detergents can also disrupt the skin’s lipid barrier, increasing permeability and subsequent irritation.

Risk Factors

Both intrinsic (genetic) and extrinsic (environmental) factors contribute to ICD. Factors such as age, sex, body region, and the presence of atopy can influence susceptibility. Certain occupations that involve frequent exposure to water, detergents, and other irritants are at higher risk, including healthcare workers, hairdressers, metalworkers, food workers, and construction workers. Environmental conditions like low humidity and cold temperatures can exacerbate ICD by increasing transepidermal water loss.

Irritants and Their Impact

Irritants are physical and chemical agents that can cause cellular damage when in contact with the skin for prolonged periods or at high concentrations. Common irritants include:

• Water and Wet Work: Regular exposure to water, especially in low-humidity conditions, can lead to irritant dermatitis. Wet work is defined as:

1. Hands regularly in a wet environment for over 2 hours per day.
2. Frequent hand washing (more than 20 times per day).
3. Use of hand disinfectants more than 20 times per day.
4. Use of protective gloves for over 2 hours per day or changing gloves more than 20 times per day.

• Chemical Irritants: These include detergents, surfactants, disinfectants, and antiseptics, commonly found in shampoos, cosmetics, and cleaning products. Specific examples are sodium lauryl sulfate and benzalkonium chloride, which can cause significant skin irritation.
• Physical Irritants: These involve contact with metals, tools, wood, fiberglass, plant parts like thorns and spines, wool, paper, dust, and soil. Each of these can cause different forms of dermatitis depending on the type and duration of exposure.

Clinical Features by Body Region

ICD presents differently depending on the body region affected, each with specific common causes, differential diagnoses, and management strategies:

Face and Eyelids

ICD on the face and eyelids often presents as eczema with symptoms of stinging and burning. Common causes include propylene glycol, sunscreen, and soap emulsifiers found in eye formulations. Differential diagnoses to consider are allergic contact dermatitis (ACD), which may present with marked eyelid edema, seborrheic dermatitis, and atopic dermatitis (AD). Management strategies involve developing tolerance, switching to cosmetics without emulsifiers, and using anhydrous waterproof or cake mascara.

Forehead

Lesions on the forehead may appear acneiform and can sometimes affect the face and scalp. This condition is often caused by pomades applied to the scalp, particularly in patients of color, resulting in pomade acne. Differential diagnosis includes acne vulgaris. Management includes discontinuation of irritating pomades and the use of non-comedogenic hair products.

Neck

On the neck, ICD can present as localized lichenification, frequently seen on the left side below the jaw angle. It can be caused by irritation from activities such as playing the violin (fiddler’s neck). Differential diagnosis includes run-off pattern dermatitis due to cosmetic or nail polish allergy. Management involves avoiding friction from instruments and using protective pads.

Hands

ICD on the hands typically presents as localized dermatitis without vesicles, often affecting the finger webs, dorsum of the hands, palms, and thumbs. Common causes include detergents, solvents, wet work (housewife’s eczema, dishpan hands), and occupations such as medical and dental workers, food preparation, and service workers. Differential diagnoses include ACD, which often features vesicles and favors the fingertips and nail folds; AD, which involves the dorsal hands, fingers, volar wrist, popliteal, and antecubital areas; dyshidrosis, which presents with vesicles on the sides of fingers, palms, and soles; and psoriasis, which requires examination of nails, elbows, knees, and scalp. Management strategies include the use of cold compresses and cold water, UV radiation, training programs, protective gloves, and barrier creams.

Feet

ICD on the feet often affects the interdigital spaces, presenting as lesions due to excessive sweating and wearing synthetic fiber socks or occlusive footwear. Differential diagnoses include ACD due to shoes, which typically spares the interdigital spaces; tinea pedis; and AD. Management includes wearing non-occlusive footwear, all-cotton socks, permanganate foot baths, and using dusting powders.

Diaper Area

In the diaper area, ICD presents as erythema over the external genitalia and buttocks, typically sparing the skin folds, and may progress to vesicles and bullae. Common causes include prolonged contact with urine or feces, residual antiseptics, soaps, and detergents in diapers, and friction. Differential diagnoses include Candida infection, early manifestation of psoriasis, and seborrheic dermatitis. Management involves using disposable diapers over cloth ones, applying zinc oxide ointment, and maintaining dryness.

Perineal Area

ICD in the perineal area starts as erythema with mild pruritus and can progress to erosions and vesicles. It is often caused by incontinence leading to frequent contact with urine or feces. Differential diagnosis includes ACD. Management includes coating the area with zinc oxide ointment and maintaining hygiene and dryness.

Diagnosis

ICD is diagnosed primarily by exclusion, as there is no definitive test. The diagnosis process involves:

• Patient History: Identifying potential exposure to irritants, occupational and hobby-related activities, daily routines, and family history of skin conditions.
• Clinical Examination: Observing the pattern, distribution, and morphology of lesions.
• Patch Testing: Used to rule out allergic contact dermatitis (ACD). Negative results indicate a diagnosis of ICD.
• Other Tests: Skin biopsy, measurement of transepidermal water loss (TEWL), and microbial cultures may assist in diagnosis but are not definitive.

Differences Between ICD and ACD

Pathogenesis

• ICD: Results from the direct toxic effect of an irritant on the skin, leading to non-specific inflammation. It does not involve the immune system in a sensitization process.
• ACD: Involves a delayed type IV hypersensitivity reaction. It occurs after sensitization to an allergen, which activates antigen-specific T cells upon re-exposure.

Clinical Features

• ICD: Lesions are well-demarcated, confined to the area of contact with the irritant. Symptoms include burning and stinging rather than itching.
• ACD: Lesions can spread beyond the site of contact. Intense itching is a hallmark symptom. Vesicles and edema are more common.

Diagnosis

• ICD: Diagnosed by exclusion, as there is no specific test. Patch testing is negative.
• ACD: Diagnosed using patch testing, which identifies specific allergens responsible for the reaction.

Management

The cornerstone of ICD management is the identification and avoidance of the irritant. Regular use of emollients to maintain skin barrier function is essential. In occupational settings, protective measures such as gloves and barrier creams can help reduce exposure. Topical corticosteroids may be used to control inflammation if the irritant is avoided.

• Emollients: Regular use of emollients enhances the barrier function of the skin and is a crucial part of managing ICD. Emollients should be applied frequently, especially after washing hands or exposure to irritants.
• Topical Corticosteroids: These may be used to reduce inflammation and control symptoms. Low to mid-potency corticosteroids are generally recommended, with careful monitoring to avoid potential side effects.
• Barrier Creams and Occlusive Dressings: Barrier creams can provide a protective layer on the skin, reducing exposure to irritants. Occlusive dressings may be used to enhance the effect of emollients and protect lichenified or fissured skin.
• Cold Compresses: Applying cold compresses can help reduce inflammation and soothe irritated skin. They can be particularly useful for acute flares of ICD.

Preventive Strategies

• Education and Training: Increasing awareness and education about ICD in high-risk occupations can lead to better preventive practices. Workers should be trained to recognize early symptoms of ICD and take preventive measures.
• Protective Equipment: Use of appropriate gloves and barrier creams to minimize skin contact with irritants. Ensure that protective equipment is suitable for the specific irritants encountered in the workplace and does not itself cause irritation.
• Skin Care Regimen: Regular application of moisturizers to maintain skin hydration and barrier function. Use of mild, non-irritating cleansers and avoiding harsh soaps and detergents. Implementing skin care protocols, such as scheduled breaks for applying emollients during work hours.

Workplace Adjustments

• Ergonomic Improvements: Adjusting work practices to reduce friction, pressure, and repetitive motions that can aggravate ICD. Providing tools that minimize direct skin contact with irritants.
• Environmental Controls: Improving ventilation to reduce humidity and temperature extremes. Implementing policies to limit the duration and frequency of wet work and exposure to other irritants.
• Regular Monitoring and Health Surveillance: Conducting regular skin examinations and monitoring for early signs of ICD, especially in high-risk occupations. Providing access to dermatological care for early intervention and treatment.

Conclusion

ICD is a prevalent and challenging condition, particularly in occupational settings. Early recognition, proper management, and preventive measures are crucial for controlling ICD. By understanding the contributing factors and implementing effective strategies, the burden of ICD can be significantly reduced. Differentiating between ICD and ACD is essential for appropriate management, as their treatment and preventive approaches differ significantly.

References

• Patel, K., & Nixon, R. (2022). Irritant contact dermatitis—a review. Current Dermatology Reports, 11(2), 41-51.
• Bains, S. N., Nash, P., & Fonacier, L. (2019). Irritant contact dermatitis. Clinical Reviews in Allergy & Immunology, 56(1), 99-109.