Diagnosis and management of hypersensitivity reactions caused by oxaliplatin

Hypersensitivity reactions to oxaliplatin have been increasing since its introduction at the end of the 1990s, but allergy tests with antineoplastic drugs are rarely used to aid diagnosis. We describe 5 cases in which hypersensitivity reactions to oxaliplatin after several courses of chemotherapy were managed by allergy testing and desensitization. Skin prick tests were negative at 1 mg/mL in all patients, positive at 10 mg/mL in 2 tested patients, and negative in 10 control subjects. Intradermal tests were positive and not irritant at 0.01 to 0.001 mg/mL concentrations. A desensitization protocol with increasing concentrations and flow rates was successfully completed in all patients. We conclude that prick and intradermal skin tests are useful in the diagnosis of hypersensitivity reactions to oxaliplatin and that the desensitization protocol performed avoided discontinuation of chemotherapy in all patients.

Cross-reactivity among p-amino group compounds in sulfonamide fixed drug eruption: diagnostic value of patch testing

We studied 28 patients with fixed drug eruption (FDE) caused by sulfonamide antibiotics to investigate cross-reactivity between sulfonamide derivatives and p-amino compounds and to explore the usefulness of patch testing, as an alternative to controlled oral challenge testing (COCT), in diagnosis within this clinical area. COCT with sulfamethoxazole (SMX), sulfadiazine (SDZ), sulfamethizole (SMZ), furosemide (FU), procaine (PRO) and glipizide (GPZ) was performed. Patch testing (PT) with SMX and SDZ was carried out. In all patients, the diagnosis of FDE was confirmed by positive COCT and allergy to trimethoprim ruled out by COCT. 42.8 and 31.8% of the SMX-induced FDE patients reacted to SMZ and SDZ, respectively. All patients (n = 28) tolerated FU, PRO and GPZ. COCT performed with the 3 sulfonamide antibiotics in 12 patients was positive in 2 subjects with the 3 drugs, in 2 patients only with SMX and SMZ and in the remaining 8, SMX was the only causative drug. PT was positive in 5 of 25 patients positive on COCT. The probability of obtaining a positive PT was higher among patients who had a residual lesion than that among those who lacked this. Cross-reactivity between different sulfonamide antibiotics is thus variable, being most likely between SMX and SMZ. We have found no cross-reactivity between sulfonamide antibiotics and other sulfonamide derivatives or p-amino drugs in FDE. PT is a useful tool in the diagnosis of FDE, especially if there are residual lesions, because it avoided the need for COCT in 20% of patients.

Fixed drug eruption induced by indapamide. Cross-reactivity with sulfonamides

Indapamide is a nontiazidic sulfonamide diuretic which has not been previously reported as a cause of fixed drug eruption. We describe a patient who experienced several episodes of fixed drug eruption during treatment with indapamide. The diagnosis was confirmed by positive controlled oral challenge test. The possible existence of cross-reactivity with other sulfonamide derivatives was investigated by controlled oral challenge test with sulfamethoxazole, sulfadiazine and furosemide, with the tests with sulfamethoxazole and sulfadiazine resulting positive.

Clinical tolerance, parasitological efficacy and environmental effects of dehumidifiers in stable asthmatics sensitized to house dust mites

Dehumidifiers (DH) are potentially effective appliances as coadjuvant therapy in the treatment of bronchial asthma caused by sensitization to house dust mites. The aims of this study were to analyze DH tolerance in asthmatic patients, to assess the parasitological effects and to analyze the environmental effects produced by the use of these appliances in the bedrooms of asthmatic patients sensitized to house dust mites. 10 stable asthmatic patients sensitized to house dust mites were studied. DH appliances (CD-300) were installed in their bedrooms. Each patient was given symptom scoring tables and a portable peak expiratory flow (P.E.F.) during a period of 5 months, 1 month before installing the DH and 4 months afterwards. To study the parasitological efficacy of the DHs, we analyzed dust samples from the bedrooms and determined the Der p I, Der f I and Der II allergens by means of a modified ELISA based on monoclonal antibodies. Dust samples were collected before installing the DHs and after they had been working for 2 and 4 months. Dry temperature and relative humidity measurements at three time intervals (7-9, 15-17 and 22-24 h) were carried out. The 1st measurement was done prior to installation of the DHs in the patients' bedrooms and the 2nd and 3rd were achieved 2 and 4 months respectively after the installation. Statistical analysis was done by comparison of paired means. No significant differences were detected in the patients' symptoms nor in the P.E.F. measurements in the course of the study. Decreases in the house dust mite allergens were observed in 4 bedrooms. A significant decrease in relative humidity in the bedrooms of mite asthma patients after use of dehumidifier appliances was observed (p < 0.01). Significant differences between the measurements of the bedrooms with and without DH were detected (p < 0.01). In summary, DHs were well tolerated by stable asthmatic patients, produced a significant decrease in the relative humidity level and showed some parasitological efficacy.

Cross-sensitivity among oxicams in piroxicam-caused fixed drug eruption: two case reports

Fixed drug eruption (FDE) caused by oxicams is very rare. There are few reports of FDE induced by piroxicam, and this explains why cross-sensitivity among oxicams (piroxicam, tenoxicam, and droxicam) has been studied in only one patient. The patch test on residual lesions has lately been used by some authors in FDE diagnosis with variable results. We describe two cases of piroxicam-caused FDE and demonstrate cross-sensitivity among piroxicam, tenoxicam, and droxicam in both of them. One patient had residual lesions and the patch test was useful for diagnosis and cross-sensitization studies. The second patient had no residual lesions, and the patch test was negative on normal but previously affected skin; therefore, the study was performed by single-blind controlled oral challenge.