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Biomedical subjects

P Trechot

Publications and source records attributed to P Trechot.

At least 37 records · Page 2Linked to original sources
PubMed2004

Drug skin tests in cutaneous adverse drug reactions to pristinamycin: 29 cases with a study of cross-reactions between synergistins.

The present study was made to determine the value of drug skin tests in patients with cutaneous adverse drug reactions (CADRs) due to a synergistin (pristinamycin) and to determine the frequency of cross-reactions between synergistins. 29 patients were referred during the onset of the CADR due to pristinamycin: 18 with maculopapular rash, 9 erythrodermas, 1 angioedema and 1 Stevens-Johnson syndrome. They all had patch tests with pristinamycin and, in most cases, with other synergistins [virginiamycin and dalfopristin-quinupristin (DQ)], prick tests (10 cases) and intradermal tests (IDT) (5 cases). Skin tests with synergistins were positive in 27 cases, patch tests with pristinamycin in 20/29 cases (69%), prick tests with pristinamycin in 3/9 cases on immediate (1 case) or on delayed (2 cases) readings, and IDT with DQ in 4/5 cases. Cross-reactions between synergistins occurred in 9/22 with virginiamycin and in 7/8 cases with DQ. Skin tests with synergistins are useful in investigating CADR due to pristinamycin. Synergistins are composed of 2 chains (1 depsipeptide and 1 macrocyclic lactone) with many structural analogies between all synergistins. According to the chemical structures and our results, it seems advisable to avoid all synergistins in patients with CADR due to pristinamycin.

Adolescent↗
PubMed2004

Low negative predictive value of skin tests in investigating delayed reactions to radio-contrast media.

Delayed reactions to radio-contrast media (RCM) with positive skin tests are rare. We report the study of a series of 15 patients who presented delayed reactions to RCM, with an analysis of the clinical features and the results of standardized drug skin tests. Patch tests were performed with RCM and iodized antiseptics (IAs). If negative, prick tests were performed, followed by intradermal tests (IDTs), then intravenous administration under hospital surveillance. The main clinical features were maculopapular rashes or a macular rubella-like rashes. Patch tests were positive with RCM in 2 of 15 cases and with IAs in 4 of 15 cases. All the prick tests were negative. IDTs were positive at 24 h in 8 of 15 cases. 5 of 12 patients had a non-severe relapse of the rash upon receiving an RCM despite clearly negative skin tests with the readministered RCM. Visipaque cross-reacted with Iopamiron, Iomeron, Telebrix, Omnipaque, Xenetix and Hexabrix. Omnipaque cross-reacted with Hexabrix and Iopamiron. IDTs with delayed readings are of better value than patch tests in such patients. The readministration of RCM with negative IDTs must be performed with progressive amounts under hospital surveillance. Cross-reactions between various classes of RCM are frequent. The responsible epitopes are unknown. Iodine itself could be involved.

Adult↗
PubMed2001

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↗
PubMed2001

[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↗