An economic evaluation of patch testing in the diagnosis and management of allergic contact dermatitis.
BACKGROUND
A previous retrospective study indicated that patch testing is cost-effective and well accepted by patients.


OBJECTIVE
The objective of this observational prospective study was to show the cost-effectiveness of patch testing in patients suspected of allergic contact dermatitis (ACD) and to determine the order in which different severity groups rank in terms of cost-effectiveness.


METHODS
This observational study was conducted in 567 patients from 10 investigator sites over a period of 1 year. All patients with a suspicion of contact allergy who exhibited at least moderate disease activity were included in the study and were stratified according to disease severity and whether or not they were patch tested. In each severity category, the cost-effectiveness of patch testing was evaluated. Patients who were ruled out for contact allergy by the first 6 months after admission were excluded. A validated dermatology-specific quality of life instrument was administered to all the patients at entrance into the study and at 6 and 12 months after that. The cost-effectiveness analysis is shown using a decision analysis model.


RESULTS
Patch testing was performed on 22% of patients with mild disease, 41% of patients with moderate disease, and 50% of patients with severe disease. As a result of changes made in their lifestyle, 66% in the patch-tested group and 51% in the non-patch-tested group reported 75% or more improvement in disease symptoms after 6 months. Early confirmation of diagnosis helped reduce the prediagnosis costs of treatment, which was mostly based on preliminary diagnosis. The greatest quality of life benefits from patch testing, relative to no patch testing, occurred in subjects with recurrent or chronic ACD.


CONCLUSIONS
Patch testing is most cost-effective and reduces the cost of therapy in patients with severe ACD.
Rajagopalan
R
R
Glaxo Dermatology, a division of Glaxo Wellcome Inc, Research Triangle Park; Bowman Gray School of Medicine, Winston-Salem; and PharmaResearch Corporation, Wilmington, NC; and University of Louisville School of Medicine, Louisville, KY, USA.
Anderson
R T
RT
Sarma
S
S
Kallal
J
J
Retchin
C
C
Jones
J
J
Fowler
J F
JF
Sherertz
E F
EF
D002908:Chronic Disease; D003363:Cost Control; D003362:Cost-Benefit Analysis; D003661:Decision Support Techniques; D017449:Dermatitis, Allergic Contact / Q000175:diagnosis* / Q000191:economics / Q000628:therapy; D005069:Evaluation Studies as Topic; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D010328:Patch Tests / Q000191:economics*; D011446:Prospective Studies; D011788:Quality of Life; D012008:Recurrence; D015203:Reproducibility of Results; D012720:Severity of Illness Index