Paeds · paediatric-dermatology
Contact dermatitis
Also known as Irritant contact dermatitis · Allergic contact dermatitis · Contact eczema · Patch test dermatitis
Fellowship guide to contact dermatitis in children: how to tell irritant from allergic disease at the bedside, the common culprits (nickel, fragrances, methylisothiazolinone, neomycin, saliva, wet work), when a recurrent or treatment-resistant eczema is hiding an allergy, the role and reading schedule of patch testing, and how barrier repair, allergen avoidance and potency-matched topical corticosteroids resolve the lesion while preventing the chronic, infected and facially disfiguring complications.
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Red flags
- An eczema that localises to one anatomical site, recurs in the same place, or fails to respond to appropriate atopic eczema therapy is allergic contact dermatitis until patch testing proves otherwise — a distribution clue outweighs a generic atopic history
- Allergic contact dermatitis is a delayed type IV reaction and does not occur on first exposure — a child who reacts within minutes of contact has a type I urticarial or anaphylactic allergy, not contact dermatitis, and needs immediate management
- A periumbilical, earlobe, wrist or nickel-buckle distribution rash in an atopic child is nickel allergic contact dermatitis — nickel is the single most frequent paediatric allergen and avoidance resolves the lesion
- Erythema, vesiculation and weeping that spread beyond the contact site with regional lymphadenopathy and systemic upset may represent secondary bacterial infection with Staphylococcus aureus or streptococcus, or rarely eczema herpeticum — escalate, swab and treat, do not assume a flare
- Reading a patch test too early or on inflamed skin gives false results and dangerous reassurance — the decisive reading is at 72 to 96 hours, and an angry back with multiple positives demands repeat testing of individual allergens
Life stages
Care settings
Clinical exam formats
Board mappings
- Dermatology
- Common skin conditions
- Contact dermatitis
- General Paediatrics learning goal — distinguish irritant from allergic contact dermatitis and use patch testing
- Atopic eczema that fails therapy or localises to one site warrants patch testing
- Nickel, fragrance and preservative allergies in childhood
- Clinical Applications
- Common skin eruptions
- Short Cases
- Communication scenarios
- Dermatology: recognises and manages contact dermatitis
- Allergy: understands type IV hypersensitivity and patch testing
- Skin eruptions resistant to standard therapy
- Foundation of Practice (FOP)
- Applied Knowledge in Practice (AKP)
- Contact dermatitis and patch testing
- Clinical
- History
- Communication
- Dermatological examination
- General Pediatrics Content Outline — Dermatology
- Contact dermatitis and allergic skin disorders
- Patch test interpretation
- Patient Care 1: History and Physical Examination
- Patient Care 4: Clinical Reasoning
- Medical Knowledge 1: Clinical Knowledge of contact dermatitis
- Systems-Based Practice 1: coordination with dermatology and allergy
- Medical Expert
- Collaborator
- Pediatrics: Core EPA — diagnose and manage common dermatoses
Overview & Definition
Picture the eight-year-old who returns to clinic with the same angry, weeping band of eczema around her navel that cleared with steroid last month and came back the day she wore her favourite jeans with the metal button. Her atopic eczema elsewhere is well controlled, yet this one patch refuses to settle. That pattern — a same-site, recurrent, anatomically-clued eruption — is the fingerprint of allergic contact dermatitis, and it is the scenario every general paediatrician must learn to spot. [8]
Contact dermatitis is an eczematous skin inflammation arising from direct skin contact with an exogenous agent. It is divided into irritant contact dermatitis, caused by the direct cytotoxic effect of a chemical or physical agent on the skin cells, and allergic contact dermatitis, a cell-mediated delayed type IV hypersensitivity reaction to a specific allergen. A third, overlapping pattern is photocontact dermatitis, in which a topical or systemic agent becomes allergenic or irritant only in the presence of ultraviolet light. In children, irritant disease is far more common than allergic disease, but the latter is increasingly recognised as patch testing becomes more available. [11] [10]
Three ideas anchor the whole topic. First, the morphology of contact dermatitis is eczematous — erythema, vesicles, weeping, scaling and eventually lichenification — so it mimics and often coexists with atopic eczema, which is the commonest source of diagnostic error. Second, the distribution is the key to the cause: a sharply demarcated eruption in the shape of the offending object or at the site of contact points straight to a contactant, whether irritant or allergic. Third, the distinction between irritant and allergic disease matters because management differs — both need removal of the cause and barrier repair, but only allergic disease benefits from patch testing, allergen identification and long-term avoidance counselling. [8] [9]
References12ShowHide
- [1]Johansen JD, Aalto-Korte K, Agner T, Andersen KE, Bircher A, et al. European Society of Contact Dermatitis guideline for diagnostic patch testing - recommendations on best practice. Contact Dermatitis, 2015.PMID 26179009
- [2]Tam I, Yu J Allergic Contact Dermatitis in Children: Recommendations for Patch Testing. Curr Allergy Asthma Rep, 2020.PMID 32548648
- [3]de Waard-van der Spek FB, Darsow U, Mortz CG, et al. EAACI position paper for practical patch testing in allergic contact dermatitis in children. Pediatr Allergy Immunol, 2015.PMID 26287570
- [4]DeKoven JG, Silverberg JI, Warshaw EM, et al. North American Contact Dermatitis Group Patch Test Results: 2017-2018. Dermatitis, 2021.PMID 33970567
- [5]Simonsen AB, Johansen JD, Deleuran M, Mortz CG, Sommerlund M, et al. Contact allergy in children with atopic dermatitis: a systematic review. Br J Dermatol, 2017.PMID 28470762
- [6]Neale H, Garza-Mayers AC, Tam I, et al. Pediatric allergic contact dermatitis. Part 2: Patch testing series, procedure, and unique scenarios. J Am Acad Dermatol, 2021.PMID 33217511
- [7]Yu J, Atwater AR, Brod B, et al. Pediatric Baseline Patch Test Series: Pediatric Contact Dermatitis Workgroup. Dermatitis, 2018.PMID 29933256
- [8]Seth D, Poowuttikul P, Kamat D, et al. Contact Dermatitis in Children. Pediatr Ann, 2021.PMID 34044703
- [9]Brown C, Yu J Pediatric Allergic Contact Dermatitis. Immunol Allergy Clin North Am, 2021.PMID 34225896
- [10]Tam I, Yu J Pediatric contact dermatitis: what's new. Curr Opin Pediatr, 2020.PMID 32618793
- [11]Simonsen AB, Deleuran M, Johansen JD, Sommerlund M Contact allergy and allergic contact dermatitis in children - a review of current data. Contact Dermatitis, 2011.PMID 21851361
- [12]Alves da Silva C, Bregnhøj A, Mowitz M, et al. Contact dermatitis in children caused by diabetes devices. Contact Dermatitis, 2022.PMID 35634681