Continuing medical educationAllergic contact dermatitis: Patient diagnosis and evaluation
Section snippets
Pathophysiology: Basic science
ACD is a type IV, delayed-type reaction that is caused by skin contact with allergens that activate antigen-specific T cells in a sensitized individual. The sensitized T cells are primarily T-helper 1 (TH1) type. In the sensitization phase, innate immunity is activated through keratinocyte release of interleukin (IL)-1α, IL-1β, tumor necrosis factor–alpha, granulocyte-macrophage colony-stimulating factor, and ILs-8 and -18. Langerhans and dermal dendritic cells uptake the allergen and migrate
Indication for patch testing
Patch testing is the criterion standard in the diagnosis of ACD. Patch testing attempts to recreate, in vivo, an allergic reaction to nonirritating concentrations of an allergen that is suspended in a vehicle. The decision to perform patch testing and which allergens to test depends on many factors.
Some common indications for patch testing include: (1) distributions that are highly suggestive of ACD—for example, ACD of the hands, feet, face, and eyelid, as well as unilateral presentations; (2)
Supplies
In addition to allergens, other supplies required include tape, a refrigerator for storage of the allergens, chambers, A Wood's lamp, markers, and maps.
Patch tests are used to identify the cause of ACD and aim to reproduce an eczematous reaction to a causative allergen applied to intact skin. Closed patch testing involves the application of allergens under occlusion to the skin of the upper aspect of the back for a period of 2 days. Readings are generally performed at that time, with additional
New/emerging allergens
Advances in technology and the continually evolving nature of industry results in the introduction of many new chemicals into the environment and personal care products. This results in new consumer exposure and potential new allergens. The number of new products developed annually is substantial; the number of new allergens is sizeable. Clinicians must be aware that new, yet to be described allergens may be responsible for a patient's ACD. Only with investigative work by the patient,
References (123)
- et al.
Atopic dermatitis results in intrinsic barrier and immune abnormalities: implications for contact dermatitis
J Allergy Clin Immunol
(2013) - et al.
Dermal Langerhans cell–deficient mice develop enhanced contact hypersensitivity
Immunity
(2005) - et al.
1,25-dihydroxyvitamin D. experts similar immunosuppressive effects as UVR but is dispensable for local UVR- induced immunosuppression
J Invest Dermatol
(2012) Ingested food in systemic allergic contact dermatitis
Clin Dermatol
(1997)- et al.
Systemic contact dermatitis to raw cashew nuts in pesto sauce
Am J Contact Dermat
(1998) - et al.
Prevalence of patch testing and methodology of dermatologists in the US: results of a cross-sectional survey
Am J Contact Dermat
(2002) - et al.
The utility of patch tests using larger screening series of allergens
Am J Contact Dermat
(1998) - et al.
The detection of clinically relevant contact allergens using a standard screening tray of twenty-three allergens
J Am Acad Dermatol
(2003) - et al.
An economic evaluation of patch testing in the diagnosis and management of allergic contact dermatitis
Am J Contact Dermat
(1998) - et al.
Good clinical practice in patch testing: readings beyond day 2 are necessary a confirmatory analysis
Am J Contact Derm
(1996)
Delayed patch test reading after 5 days: the Mayo Clinic experience
J Am Acad Dermatol
Thimerosal: contact (non)allergen of the year
Am J Contact Dermat
Deodorants: an experimental provocation study with cinnamic aldehyde
J Am Acad Dermatol
Correlations of patch test reactivity and the repeated open application test (ROAT)/provocative use test (PUT)
Food Chem Toxicol
The time–dose–response relationship for elicitation of contact dermatitis in isoeugenol allergic individuals
Toxicol Appl Pharmacol
Radioactive method of the measurement of lymphocyte transformation in vitro
Lancet
Non-specific lymphocyte transformation in vitro by nickel acetate. A possible source of errors in lymphocyte transformation test(LLT)
J Invest Dermatol
Patients with allergic contact dermatitis to nickel and nonallergic individuals display different nickel-specific T cell responses. Evidence for the presence of effector CD81and regulatory CD41 T cells
J Invest Dermatol
The diagnostic value of atopy patch testing and prick testing in atopic dermatitis: facts and controversies
Clin Dermatol
Evaluating the relevance of aeroallergen sensitization in atopic eczema with the atopy patch test: a randomized, double-blind multicenter study
J Am Acad Dermatol
The relationship between positive aeroallergen patch test reactions and aeroallergen exacerbations of atopic dermatitis
Clin Immunol Immunopathol
Combined skin prick and patch testing enhances identification of food allergy in infants with atopic dermatitis
J Allergy Clin Immunol
The diagnostic accuracy of the atopy patch test in diagnosing hypersensitivity to cow's milk and hen's egg in unselected children with and without atopic dermatitis
J Am Acad Dermatol
Double-blind controlled trial of effect of house dust-mite allergen avoidance on atopic dermatitis
Lancet
Aeroallergen patch testing for patients presenting to contact dermatitis clinics
J Am Acad Dermatol
Association between severity of atopic eczema and degree of sensitization to aeroallergens in schoolchildren
J Allergy Clin Immunol
American Contact Dermatitis Society Core Allergen Series Committee
Dermatitis
Evolution of patch testing
Dermatitis
Giant steps in patch testing: a historical memoir
The continuing rise of contact dermatitis, Part 1: The academic discipline
Contact Dermatitis
Human epidermal Langerhans cells maintain immune homeostasis in skin by activating skin resident regulatory T cells
Immunity
Glucocorticosteroids modify Langerhans cells to produce TGF-β and expand regulatory T cells
J Immunol
The patch test – who should and should not use it and why
Contact Dermatitis
Contact dermatitis
Hematogenous contact eczema following oral administration of neomycin
Hautarzt
Contact eczema from methyl salicylate reproduced by oral aspirin (acetyl salicylic acid)
Contact Dermatitis
The baboon syndrome: systemically-induced allergic contact dermatitis
Contact Dermatitis
Systemic contact dermatitis presenting as lichen planus of the lip
Dermatitis
Systemic allergic dermatitis of the lips resulting from allergy to an antimicrobial agent in contact lens disinfecting solution
Contact Dermatitis
Systemic contact dermatitis in children: how an avoidance diet can make a difference
Pediatr Dermatol
Periocular dermatitis from systemic exposure to nickel in a palatal expander and dental braces
Dermatitis
Contact Dermatitis and Related Disorders
Patch testing. Test Concentrations and Vehicles for 4350 Chemicals
Patch Testing and Prick Testing
North American Contact Dermatitis Group Patch Test results for 2009-1010
Dermatitis
North American Contact Dermatitis Group. Patch test results for 2007-2008
Dermatitis
Prevalence of botanical extract allergy in patients with contact dermatitis
Dermatitis
The outcome of an additional patch-test reading on days 6 or 7
Contact Dermatitis
Patch testing in patients treated with systemic immunosuppression and cytokine inhibitors
Contact Dermatitis
Oral prednisolone suppresses allergic but not irritant patch test reactions in individuals hypersensitive to nickel
Contact Dermatitis
Cited by (0)
Funding sources: None.
Conflicts of interest: None declared.
Date of release: June 2016
Expiration date: June 2019