Value of patch testing in atopic dermatitis.
BACKGROUND
Because patients with atopic dermatitis are less prone to type IV allergies, there has been controversy regarding the role of patch testing in these patients.


OBJECTIVE
The present study was conducted to evaluate the role of patch testing in atopic individuals.


METHODS
One-hundred patients with hand eczema were patch tested using the standard patch test battery (HERMAL, Kurt Herrmann, Reinbek, West Germany) and the Finn chamber units. The total immunoglobulin class E (IgE) level was determined and correlated to the results of patch testing.


RESULTS
Eighty-seven patients had positive patch test reactions. Among the 87 patients, 39 (44.8%) had atopic dermatitis. The most common allergens yielding positive results were nickel sulfate, 2.5%, (58.6%); potassium dichromate, 0.25% (56.3%); carba mix, 3%, (44.82%); formaldehyde, 1% in H2O, (40.22%); neomycin sulfate, 20%, (33.3%); and balsam of Peru 25%, (17.24%) respectively. Patients with atopic dermatitis were more frequently sensitive to neomycin sulfate than nonatopics.


CONCLUSIONS
Patients with atopic dermatitis should be patch tested when indicated because they also develop contact allergic sensitization to a significant degree. Our observations indicate that patch testing with standard allergens often adds valuable information about contact sensitivity in these patients.
el Samahy
M H
MH
Department of Dermatology, Ain Shams University, Egypt.
el-Kerdani
T
T
D000328:Adult; D000485:Allergens / Q000009:adverse effects; D000900:Anti-Bacterial Agents / Q000009:adverse effects; D001453:Balsams / Q000009:adverse effects; D002424:Caustics / Q000009:adverse effects; D003876:Dermatitis, Atopic / Q000175:diagnosis* / Q000276:immunology; D004050:Ditiocarb / Q000009:adverse effects; D005069:Evaluation Studies as Topic; D005404:Fixatives / Q000009:adverse effects; D005557:Formaldehyde / Q000009:adverse effects; D006146:Guanidines / Q000009:adverse effects; D006229:Hand Dermatoses / Q000175:diagnosis / Q000276:immunology; D006801:Humans; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007073:Immunoglobulin E / Q000032:analysis; D007509:Irritants / Q000009:adverse effects; D008875:Middle Aged; D009355:Neomycin / Q000009:adverse effects; D009532:Nickel / Q000009:adverse effects; D010328:Patch Tests; D011192:Potassium Dichromate / Q000009:adverse effects; D013859:Thiocarbamates / Q000009:adverse effects
D000485:Allergens; D000900:Anti-Bacterial Agents; D001453:Balsams; D002424:Caustics; D005404:Fixatives; D006146:Guanidines; D007509:Irritants; D013859:Thiocarbamates; C057051:carbamix; D005557:Formaldehyde; D007073:Immunoglobulin E; C029938:nickel sulfate; D009532:Nickel; C025080:Peruvian balsam; D004050:Ditiocarb; D009355:Neomycin; D011192:Potassium Dichromate