Basics
Description
An acute or chronic inflammation of the dermis and epidermis as result of either direct irritation to the skin (irritant contact dermatitis) or delayed-type (type IV) hypersensitivity reaction to a contact allergen (allergic contact dermatitis) �
Epidemiology
Incidence
Incidence in children is not known. �
Prevalence
- Irritant contact dermatitis: Most cases of contact dermatitis (>80%) are irritant contact dermatitis.
- Skin reactivity is highest in infants and tends to decrease with age.
- Allergic contact dermatitis
- Because children have less time to develop sensitivities, it is less common in infants and children than in adults.
- Prevalence increases with age.
- Overall prevalence is ~13-23% and has been increasing in children, perhaps due to more frequent exposure to allergens at a younger age or improved diagnosis.
Risk Factors
- Irritant contact dermatitis
- Frequent hand washing or water immersion
- Atopic dermatitis: Chronically impaired barrier function increases susceptibility to irritants.
- Genetic factors
- Environmental factors such as cold/hot temperatures or high/low humidity disrupt the skin barrier.
- Allergic contact dermatitis
- Atopic dermatitis
- Genetic factors
- Increased exposure to allergens
General Prevention
Minimize contact exposure to known or potential irritants and allergens. �
Pathophysiology
- Irritant contact dermatitis does not involve an immune response and thus can occur with the first exposure to the irritant. Multiple mechanisms are involved, including the following:
- Disruption of the epidermal barrier by chemicals (soaps, detergents) or physical irritants (moisture, friction)
- Damage to cell membranes and cytotoxic effect on skin cells
- Chronic exposure may stimulate cell proliferation, resulting in acanthosis and hyperkeratosis. Postinflammatory hypo- or hyperpigmentation may result.
- Allergic contact dermatitis requires initial exposure and sensitization to an allergen and only occurs in susceptible individuals. Repeated exposure leads to the development of a type IV hypersensitivity reaction.
- Both processes result in nonspecific findings of dermal and epidermal edema and inflammation and may be indistinguishable from other forms of inflammatory dermatitis.
Etiology
- Irritant contact dermatitis
- Frequent hand washing or water immersion
- Soaps and detergents
- Saliva (lip licking or thumb sucking)
- Urine and feces (see "Diaper Rash"�)
- High concentrations of most chemicals can induce irritant contact dermatitis, whereas mild irritants may induce inflammation only in susceptible individuals.
- Allergic contact dermatitis
- Nickel and other metals (gold, cobalt)
- Hair products (ammonium, 5-diamine)
- Solvents (toluene-2)
- Additives to medications, cosmetics (thimerosal, mercuric chloride)
- Rubber
- Fragrances (Balsam of Peru)
- Clothing dyes
- Formaldehydes
- Topical antibiotics (neomycin, bacitracin)
- Plants (Toxicodendron species; e.g., poison ivy, poison oak, and poison sumac, which contain the allergen urushiol)
Diagnosis
History
- Patients may present with either acute or chronic localized, pruritic dermatitis.
- Patients should be asked about all chemicals and potential irritants or allergens to which they are intermittently or frequently exposed.
- Many patients are unable to associate a specific allergen with symptom development.
- Timing of symptoms
- Irritant contact dermatitis: immediate inflammation
- Allergic contact dermatitis: inflammation 48-72 hours but occasionally several days after exposure
- Location of skin changes may provide clues, as reactions are typically localized to the areas that come in contact with the allergen.
Physical Exam
- Irritant contact dermatitis
- Acute: ranges from mild skin dryness and mild erythema to erythematous papules and patches, edema, vesicles, and oozing; in severe cases, may result in a chemical burn (skin necrosis)
- Chronic: erythema, dryness, lichenification, hyperkeratosis, and cracking
- A perioral rash often signifies an irritant contact dermatitis from lip licking.
- Allergic contact dermatitis
- Acute: pruritus, erythema, and edema with vesicles or bullae that often rupture, leaving a crust
- Chronic: lichenification, erythema, scaling
- Often an unusual pattern or distribution that correlates with pattern of exposure (e.g., a linear pattern as patient brushes against poison ivy, round lesion on abdomen where skin contacts nickel button on jeans)
- Autoeczematization or "id"� reaction: A more generalized dermatitis may develop distal to the original site of contact 1 or more weeks after the initial localized dermatitis.
Diagnostic Tests & Interpretation
Lab
In general, routine laboratory testing is not helpful in confirming the diagnosis of contact dermatitis. �
Diagnostic Procedures/Other
- Formal epicutaneous patch testing distinguishes irritant and allergic contact dermatitis and identifies inciting allergens; may be performed by clinicians experienced in the interpretation of the test
- The patch test involves the controlled exposure of multiple allergens to the skin. Positive reactions manifest with the development of erythema, edema, and vesicles at the site of exposure, usually within 48-96 hours. It may be performed using a standard panel of allergens or by the application of selected allergens at the discretion of the specialist.
- Patch testing for poison ivy or oak is not recommended because reactions may be severe.
Pathologic Findings
- Skin biopsy is rarely necessary but may help differentiate between contact dermatitis and psoriasis or other inflammatory dermatoses.
- Skin biopsy findings may not be specific, and histopathologic features may not differentiate irritant from allergic contact dermatitis.
Differential Diagnosis
- Infection
- Impetigo and cellulitis: Bacterial infections of the skin (Staphylococcus aureus or group A Streptococcus) may manifest as erythematous, edematous, crusted patches and plaques. Pustules and/or deep-seated inflammatory nodules may be present. Infection is usually associated more with pain and tenderness than with pruritus.
- Fungal infection: KOH examination can clarify the diagnosis.
- Scabies: intensely pruritic papules and nodules with a predilection for the hands and feet (especially the web spaces), the axillae, and the groin. Close contacts are often affected.
- Herpes simplex virus may present with vesicles but is less erythematous and pruritic and more painful.
- Metabolic
- Acrodermatitis enteropathica: a genetic or acquired zinc deficiency with characteristic bullae and erosions involving hands, feet, and periorificial areas (perioral, periocular, and perineal). Associated with failure to thrive, diarrhea, and alopecia
- Immunologic
- Atopic dermatitis: It may favor the face and extremities or occur more diffusely with truncal involvement; usually spares diaper, perinasal, and periocular areas; usually symmetric; associated with erythematous, excoriated, and crusted papules, patches, and plaques and with chronic pruritus, often worse at night; often accompanied by a personal or family history of atopy
- Seborrheic dermatitis: usually affects infants <1 year of age or adolescents; erythema and greasy scaling patches that favor scalp, face, ears, and intertriginous areas; usually asymptomatic
- Nummular eczema: a chronic, often intensely inflammatory and pruritic dermatitis with multiple round, crusted, edematous, erythematous patches and plaques, often on extremities
- Psoriasis vulgaris: a chronic dermatitis with recurrent well-defined erythematous plaques with silvery scale; commonly affects scalp, elbows, and knees; nail changes may be present.
- Other
- Ichthyoses: diffuse, severely dry, scaly, and hyperkeratotic skin; acquired or inherited
- Pityriasis rosea: may begin with a single round, sharply demarcated, pink "herald"� patch on the torso which becomes scaly and develops central clearing, followed by crops of oval lesions on the trunk and proximal extremities
- Child abuse: inflicted trauma or burns
Treatment
Medication
First Line
- Topical corticosteroids may help with the pruritus and inflammation associated with both acute and chronic contact dermatitis. Some mild cases may not require treatment and may self-resolve in 1-2 weeks.
- In irritant contact dermatitis, topical corticosteroids are controversial, as efficacy has not been evaluated in randomized controlled studies. Potential benefits must be weighed against the adverse effects.
- Milder forms not involving the face or flexural areas can be treated with class 3-5 topical corticosteroids for a short duration.
- For severe or chronic contact dermatitis with lichenification not involving the face of flexural areas, a medium- to high-potency topical corticosteroid (class 2-4) should be used for a short duration (2 weeks).
- If involving the face or flexural areas, medium- to high-potency topical corticosteroids should be avoided; instead, use a low-potency topical corticosteroid (class 6 or 7).
- Systemic antihistamines (diphenhydramine or hydroxyzine) are generally not necessary but can be considered if pruritus is extreme. There is no evidence that topical antihistamines are useful in treatment of pruritus.
- In severe cases involving a large body surface area or associated with significant facial, genital, or extremity edema, a short course (7-10 days) of systemic corticosteroids (prednisone 1-2 mg/kg/24 h) may be appropriate, with tapering over 1-2 weeks to avoid a rebound of the dermatitis.
Second Line
The intermittent use of a topical calcineurin inhibitor such as tacrolimus or pimecrolimus, which have anti-inflammatory and steroid-sparing properties, may be considered as adjunctive therapy in patients with chronic contact dermatitis. These agents are less effective than mid-potency corticosteroids, and the FDA issued an advisory about the possible link between topical use of calcineurin inhibitors and cancer. They should not be used in children younger than 2 years of age. �
Additional Treatment
General Measures
- The most effective treatment involves identification and avoidance of the offending allergens or exposures. This often requires extensive education of the patient and family regarding potential sources of exposure.
- Emollients restore epidermal barrier function. Petrolatum-based products are preferred to emollients containing lanolin or fragrances to reduce the risk of contact sensitization. Frequent application is recommended.
- Prompt bathing with soap and water immediately after exposure to poison ivy, oak, or sumac may help reduce exposure to the allergen in susceptible individuals.
- Chemical inactivators of urushiol may decrease dermatitis, but oil-removing compounds and soap also decrease dermatitis when used promptly after exposure.
- Acute allergic contact dermatitis: Application of cool compresses and shake lotions with drying properties (e.g., calamine lotion) can be helpful. Products containing colloidal oatmeal may also be helpful in soothing inflamed skin.
Ongoing Care
Follow-up Recommendations
Patient Monitoring
Patients who do not improve after 1-2 weeks of therapy should be reevaluated. �
Patient Education
Prevention �
- Patients should be instructed on allergen avoidance, including the use of protective gloves and clothing where appropriate.
- Barrier creams containing quaternium-18 bentonite (bentoquatam 5%) may prevent exposure to the allergen in poison ivy if applied prior to anticipated exposure. Protective clothing may be helpful but can harbor the allergenic resin for many days.
Prognosis
Complete resolution can be expected after appropriate treatment and elimination of further exposure to the allergen. �
Complications
Generally, there are no long-term complications, although secondary bacterial infections may occur. �
Additional Reading
- Bonitsis �NG, Tatsioni �A, Bassioukas �K, et al. Allergens responsible for allergic contact dermatitis among children: a systematic review and meta-analysis. Contact Dermatitis. 2011;64(5):245-257. �[View Abstract]
- De Waard-van der Spek �FB, Andersen �KE, Darsow �U, et al. Allergic contact dermatitis in children: which factors are relevant? (review of the literature) Pediatr Allergy Immunol. 2013;24(4):321-329. �[View Abstract]
Codes
ICD09
- 692.9 Contact dermatitis and other eczema, unspecified cause
- 692.89 Contact dermatitis and other eczema due to other specified agents
- 691.8 Other atopic dermatitis and related conditions
- 692.6 Contact dermatitis and other eczema due to plants [except food]
- 692.1 Contact dermatitis and other eczema due to oils and greases
- 692.2 Contact dermatitis and other eczema due to solvents
- 692.4 Contact dermatitis and other eczema due to other chemical products
- 692.0 Contact dermatitis and other eczema due to detergents
- 692.5 Contact dermatitis and other eczema due to food in contact with skin
- 692.9 Contact dermatitis and other eczema, unspecified cause
- 692.3 Contact dermatitis and other eczema due to drugs and medicines in contact with skin
ICD10
- L23.9 Allergic contact dermatitis, unspecified cause
- L24.9 Irritant contact dermatitis, unspecified cause
- L25.9 Unspecified contact dermatitis, unspecified cause
- L20.9 Atopic dermatitis, unspecified
- L24.1 Irritant contact dermatitis due to oils and greases
- L24.2 Irritant contact dermatitis due to solvents
- L24.89 Irritant contact dermatitis due to other agents
- L24.4 Irritant contact dermatitis due to drugs in contact w skin
- L24.0 Irritant contact dermatitis due to detergents
- L24.3 Irritant contact dermatitis due to cosmetics
- L24.6 Irritant contact dermatitis due to food in contact with skin
- L24.81 Irritant contact dermatitis due to metals
- L24.7 Irritant contact dermatitis due to plants, except food
- L24.5 Irritant contact dermatitis due to other chemical products
ICD10
- 40275004 Contact dermatitis (disorder)
- 110979008 Irritant contact dermatitis (disorder)
- 238575004 Allergic contact dermatitis (disorder)
- 24079001 Atopic dermatitis (disorder)
- 30451004 Contact dermatitis due to detergents
- 67445002 contact dermatitis due to food in contact with skin (disorder)
- 287004008 Contact dermatitis - foods/plants (disorder)
- 86062001 Contact dermatitis due to drugs AND/OR medicine (disorder)
FAQ
- Q: Can the fluid from blisters caused by poison ivy spread the rash to other parts of the body?
- A: The contents of blisters from rhus dermatitis are not contagious. After exposure is eliminated, new lesions may appear because of the variable sensitivity of various areas of the body to the allergen.
- Q: How does saliva cause a perioral rash in some kids?
- A: "Lip-licker dermatitis"� is an irritant dermatitis that results from chronic and/or excessive exposure to moisture. It is not caused by any specific substances in the saliva.