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A Barbaud

Publications and source records attributed to A Barbaud.

At least 73 records · Page 4Linked to original sources

Relevance of skin tests with drugs in investigating cutaneous adverse drug reactions.

Skin tests with drugs can be of value in investigating patients who have developed cutaneous adverse drug reactions (CADR), but their specificity and relevance remain to be determined. A false-positive result on skin testing can happen if it is not compared to results in control subjects. When performing intradermal tests (IDT), we have determined the lowest concentrations that induce false-positive results for many drugs, including betalactam antibiotics, cephalosporins, other antibiotics or non-steroidal anti-inflammatory drugs. Some drugs in their commercialized form contain sodium lauryl sulfate and can induce irritation when patch tested as such. When patch tested with colchicine at 10% in pet. or with a Cytotec pill (containing misoprostol) at 30% in pet., respectively, 80% of the 29 and 9 of the 10 negative controls developed false-positive results. Lastly, positive results of patch tests with drugs can be related to contact allergy to one of the components of the commercialized form of the drug, without any relevance to the investigation of a CADR, as observed in 2 cases with iodine or avocado oil.

Dermatitis, Irritant↗

Guidelines for performing skin tests with drugs in the investigation of cutaneous adverse drug reactions.

Skin testing with a suspected drug has been reported to be helpful in determining the cause of cutaneous adverse drug reactions (CADR). Many isolated reports of positive drug skin tests are published, but without detailed information concerning the clinical features of the CADR and the method used in performing drug skin tests, such data are not very informative. A working party of the European Society of Contact Dermatitis (ESCD) for the study of skin testing in investigating cutaneous adverse drug reactions, has proposed the herein-reported guidelines for performing skin testing in CADR in order to standardize these procedures. In each reported case, the imputability of each drug taken at the onset of the CADR and a highly detailed description and characterization of the dermatitis need to be given. Drug skin tests are performed 6 weeks to 6 months after complete healing of the CADR. Drug patch tests are performed according to the methods used in patch testing in studying contact dermatitis. The commercialized form of the drug used by the patient is tested diluted at 30% pet. (pet.) and/or water (aq.). The pure drug is tested diluted at 10% in pet. or aq. In severe CADR, drug patch tests are performed at lower concentrations. It is also of value to test on the most affected site of the initial CADR. Drug prick tests are performed on the volar forearm skin with the commercialized form of the drug, but with sequential dilutions in cases of urticaria. Intradermal tests (IDT) are performed with sterile sequential dilutions (10-4, 10-3, 10-2, 10-1) of a pure sterile or an injectable form of the suspected drug with a small volume of 0.04 ml. Drug skin tests need to be read at 20 min and also later at D2 and D4 for patch tests, at D1 for prick tests and IDT. All these tests also need to be read at 1 week. The success of skin tests varies with the drug tested, with a high % of positive results, for example, with betalactam antibiotics, pristinamycin, carbamazepine and tetrazepam on patch testing, or with betalactam antibiotics and heparins on delayed readings of IDT. The results of drug skin tests also depend on the clinical features of the CADR. The use of appropriate control patients is necessary to avoid false-positive results.

Drug Eruptions↗

[Cutaneous delayed hypersensitivity reactions to heparins and heparinoids].

INTRODUCTION: Due to cross-reactions between unfractionated heparins, low-molecular-weight heparins and sometimes heparinoids, cutaneous delayed hypersensitivity reactions might be a problem for the choice of therapeutic alternative. We report on two cases of sensitization to heparins and heparinoids. OBSERVATIONS: One woman developed localized skin reaction to a low-molecular-weight heparin, then a generalized maculopapular rash when an intravenous injection of unfractionated heparins was performed. The second patient had a localized then extended reaction to a low-molecular-weight heparin and was referred for the choice of a well tolerated method to obtain anticoagulation during a pulmonary surgery. METHODS: Patch tests, prick tests, intradermal and subcutaneous tests were performed with several unfractionated heparins, low-molecular-weight heparins, danaparoid and lepirudin in both cases. RESULTS: In the first case, tests performed with both heparins and heparinoid were positive and the use of lepirudin was proposed if anticoagulation was necessary. In the second case the subcutaneous danaparoid injection induced a localized reaction on the injection site. Danaparoid injections were continued associated with localized applications of dermocorticoids without any side effect. DISCUSSION: Cutaneous delayed hypersensitivity reactions occur on the injection site but can also be generalised. Cross reactions might be unexpected therefore skin-tests are necessary to guide the choice of a therapeutic alternative. In case of intolerance to both heparins and heparinoids various solutions may be proposed such as the application of topical corticosteroids on the injection site or the administration of hirudins. There is no cross sensitization between heparins and hirudins, but the use of hirudins is restricted and requires specific monitoring.

Drug Eruptions↗

[Sensitization to resorcinol in a prescription verrucide preparation: unusual systemic clinical features and prevalence].

BACKGROUND: Resorcinol is a rare sensitizer. In Lorraine, where it is used in high concentrations in an anti-wart ointment, this molecule has induced many cases of allergy. The purpose of this study was to describe clinical features in patients sensitized to resorcinol, to determine the incidence of sensitization in Lorraine and ascertain the occurrence of cross reactions with other phenolic pro-haptens. PATIENTS AND METHODS: The files of all patients sensitized to resorcinol were studied from 1992 to 1999. Over a 20-month period, 983 consecutive patients underwent our standard patch tests where we included resorcinol (1 p. 100 in petrolatum). Co-sensitization with other pro-haptens was studied in all sensitized patients. RESULTS: Sensitization to resorcinol was observed in 0.5 p. 100 of the 983 consecutively tested patients. Contact sensitization was found in 24 patients, who all but one had previously used the anti-wart ointment containing resorcinol. All developed contact eczema on the site of application of the ointment, with generalized urticaria (4 cases), pompholyx (1 case), and generalized papulo-vesicular rash with pompholyx (6 cases). Positive patch tests were observed with resorcinol monobenzoate (15/19 cases), pyrocatechol (7/14 cases), pyrogallol (9/19 cases), salicylaldehyde (2/17 cases), and hydroquinone (6/17 cases). Negative patch tests were observed with phenysalicylate, hexylresorcinol, or fluoresceine. CONCLUSION: Resorcinol should not be applied in high concentrations as it can provoke generalized sensitization and co-sensitization with other pro-haptens.

Administration, Cutaneous↗

[Prevalence of hyperhidrosis in a population treated by beta-blocker].

INTRODUCTION: Some cases of hyperhidrosis with beta-blocker therapy have been reported in the literature. We studied the prevalence of hyperhidrosis in a population treated by beta-blockers compared with an untreated control group. PATIENTS AND METHODS: Patients attending the cardiologic consultation of the Nancy hospital were included. Past medical history and medication were collected. Interrogation assessed whether the patient felt hyperhidrosis, and defined a hyperhidrosis score. RESULTS: Sixty-five subjects treated by beta-blocker and 100 controls were included. 36.9 p. 100 of treated patients and 38 p. 100 of controls experienced hyperhidrosis (p=0.88). 23.07 and 23 p. 100, respectively, had hyperhidrosis defined by a high score of sweating (p=0.99). Retrospectively, 8 of 24 patients experienced hyperhidrosis after the beginning of beta-blocker therapy. DISCUSSION: We observed the same prevalence of hyperhidrosis in the two groups. However sweat gland innervation involved both cholinergic and adrenergic stimulations. Furthermore, experimental studies showed an increase in sweating on efforts with beta-blocker therapy.

Adrenergic beta-Antagonists↗