In Situ Patch Test and Repeated Open Application Test for Fixed Drug Eruption: A Multicenter Study.

BACKGROUND: Few studies have evaluated allergy workup in fixed drug eruption (FDE) in a large population. OBJECTIVE: To evaluate the sensitivity of a standardized allergy workup for diagnosing the cause of FDE, with a focus on in situ repeated open application tests (ROATs). METHODS: In a retrospective multicenter study, we analyzed the practice of conducting a complete allergy workup for the etiological diagnosis of FDE. It consisted of 3 steps: in situ patch tests (PTs) for all cases except pure mucosal involvement, followed by in situ ROAT if in situ PT results were negative, and finally a drug challenge (DC). The in situ ROAT involved daily application of the suspected drug on a previously affected FDE site for 7 days. RESULTS: Of 98 suspected FDE cases, 61 patients (median age 61 y; male-to-female ratio 1.8) with a complete allergy workup were included. In 4 cases, even the DC yielded negative results. Among the remaining 57 patients with a positive workup, implicated drugs included paracetamol (12 cases), ß-lactams (11 cases), imidazoles (9 cases, including 5 with metronidazole), nonsteroidal anti-inflammatory drugs (8 cases), iodinated contrast media (4 cases), cotrimoxazole (3 cases), and various other drugs in 10 patients. The diagnosis was confirmed by in situ PT in 17 of 54 cases (31.5%), in situ ROAT in 14 of 40 cases (35%) (with 4 cases showing remote reactivation of FDE sites), and DC in 26 cases. CONCLUSIONS: The sequential allergy workup involving successively in situ PT, in situ ROAT, and DC is a reliable and safe method for diagnosing the cause of FDE. In situ tests exhibited a sensitivity of over 50%.

Impact of dupilumab on patch test results and allergic contact dermatitis: A prospective multicenter study.

BACKGROUND: Limited and conflicting data have been reported on the impact of dupilumab (DUPI) on patch test (PT) results and its efficacy against allergic contact dermatitis (ACD). OBJECTIVE: This study was undertaken to analyze PT reactivities and relevance during treatment with DUPI to determine whether they could detect ACD in patients with uncontrolled or worsened atopic dermatitis (AD) who were receiving this agent. METHODS: This prospective, multicenter study examined 76 DUPI-treated patients who had undergone PTs. The relevant information was collected during 3 visits. RESULTS: Overall, 36 patients (47%) had ≥1 positive PT reaction, and 142 PT results were positive. Twenty-three patients (30%) had ≥1 positive and clinically relevant PT result. Five of them had clinical eczema improvement after allergen avoidance. We compared the PT results of 36 patients before and during DUPI therapy, representing 1230 paired PT allergens, of which 1022 were the same, 34 were positive, 44 were lost, and 130 were uninterpretable. LIMITATIONS: Because the number of patients included remains limited, our findings should be confirmed with a larger sample. CONCLUSION: Our results confirmed the usefulness of PTs for patients receiving DUPI, with good PT reproducibility. We suggest that all DUPI-treated patients with AD developing partial responses or experiencing symptom worsening should undergo PTs to look for contact sensitization.

What is the optimal duration for a ROAT? The experience of the French Dermatology and Allergology group (DAG).

BACKGROUND AND OBJECTIVES: The repeated open application test (ROAT) is an adjuvant investigation measure to patch testing in the diagnosis of allergic contact dermatitis. ESCD recommends a 15 days duration but its overall duration varies according to publications and patients hardly adhere to prolonged ROAT duration beyond 1 week. MATERIALS AND METHODS: The Dermatology and Allergy Group of the French Society of Dermatology performed a prospective study with the aim of determining the best duration for the ROAT. RESULTS: A total of 328 ROAT results were collected for topical products, including cosmetics (60%) and topical medications (31.1%). Fifty-nine (18%) ROATs were positive, and 16 (5%) were doubtful. All the positive ROATs occurred within 10 days, with a median time to positivity of 3 days. CONCLUSION: According to our results, a minimum duration of 10 days is necessary to achieve a positive ROAT to a topical product.

Higher Frequency of Dipeptidyl Peptidase-4 Inhibitor Intake in Bullous Pemphigoid Patients than in the French General Population.

Dipeptidyl peptidase-4 inhibitors have been suspected to induce bullous pemphigoid (BP). The objective of this study was to compare the observed frequency of gliptin intake in a large sample of 1,787 BP patients diagnosed between 2012 and 2015 in France, with the expected frequency after indirect age standardization on 225,412 individuals extracted from the database of the National Healthcare Insurance Agency. The secondary objective was to assess the clinical characteristics and the course of gliptin-associated BP, depending on whether gliptin was continued or stopped. The observed frequencies of intake of the whole gliptin class and that of vildagliptin in the BP population were higher than those in the general population after age standardization (whole gliptin class: 6.0%; 95% confidence interval = 4.9-7.1% vs. 3.6%, observed-to-expected drug intake ratio = 1.7; 95% confidence interval = 1.4-2.0; P < 0.0001; vildagliptin = 3.3%; 95% confidence interval = 2.5-4.1% vs. 0.7%, ratio = 4.4; 95% confidence interval = 3.5-5.7; P < 0.0001). The association of any gliptin+metformin was also higher than in the general population, ratio = 1.8 (95% confidence interval = 1.3-2.4; P < 0.0001). Gliptin-associated BP had no specific clinical characteristics. Gliptin was stopped in 48 (45.3%) cases. Median duration to achieve disease control, rate, and delay of relapse were not different whether gliptin was stopped or continued. This study strongly supports the association between gliptin intake, particularly vildagliptin, and the onset of BP.

The European Standard Series and its additions: are they of any use in 2013?

This study has two purposes:--to know whether the European standard series is still the key reference when it comes to contact dermatitis, i.e., are its components still the most frequently involved allergens in contact dermatitis nowadays?--to assess the results of the European standard series among French and Belgian dermatologists/allergists as, so far, most of them have failed to provide statistical data within the European community of allergists/dermatologists. 18 participants from 2 dermatology and allergy centres in Belgium and 11 centres in France collected their results from 3,073 patients tested in 2011. They assessed the relevance of some tests as well as that of the standard series and additional series to establish an etiological diagnosis of contact dermatitis. These results, together with the history of the European standard series, have shown that some allergens are obsolete and that others should be included in a new standard series for which we are making a few suggestions.