Surprising results of patch testing with the baseline series in patients with photocontact allergy to ketoprofen.

OBJECTIVE: Photoallergic reactions due to topical ketoprofen are common. As some simultaneous contact allergies have been described in the literature, we aimed to get an overview of the pattern of reactivity towards common allergens in the baseline series in ketoprofen-photoallergic individuals. METHODS: Using our database, we found 94 patients with photocontact allergy to ketoprofen diagnosed during 1999-2018. Approximately 12 800 patients patch tested with the baseline series during the same time frame served as controls. Data on patch testing with the baseline series of 518 individuals belonging to the general population were obtained from an earlier study, and a comparison of allergy rates was made with the ketoprofen group. RESULTS: Contact allergy to fragrance mix I and Myroxylon pereirae was overrepresented among patients with photocontact allergy to ketoprofen (42.3% vs. 6.6% and 47.9% vs. 6.6%, p < 0.001, respectively). Significant overrepresentation was also shown for 4-tert-butylphenolformaldehyde resin (PTBP-F-R), phenol formaldehyde resin (PFR-2), black rubber mix, budesonide (all p < 0.001), and fragrance mix II (p = 0.02). The pattern was similar, but with lower significance levels for fragrance mix II and budesonide, regardless of whether or not the individuals had been photopatch tested because of a suspected photoallergic contact dermatitis from ketoprofen. CONCLUSION: Contact allergy to fragrance mix I, Myroxylon pereirae, black rubber mix, PFR-2, PTBP-FR, and to a somewhat lower extent, to fragrance mix II and budesonide, is common in individuals photoallergic to ketoprofen. It remains to be seen whether sensitisation to ketoprofen leads to simultaneous sensitisation to a number of other, chemically non-related, substances.

Allergic contact dermatitis caused by dipropylene glycol diacrylate in the Omnipod® insulin pump.

BACKGROUND: Cases of allergic contact dermatitis (ACD) caused by isobornyl acrylate (IBOA) in the Omnipod® insulin pump have previously been reported. OBJECTIVES: To present three cases of patients with ACD caused by a new allergen in the pump, and results from chemical analyses. METHODS: Omnipod pumps from different batches were analysed by gas chromatography-mass spectrometry. Aimed testing, with the department's medical device (MD) series and substances identified in the pump including dipropylene glycol diacrylate (DPGDA) at 0·01% and 0·1% in petrolatum (pet.), was performed. Patch testing also included extracts from the device, the adhesive patch as is, and allergens from baseline series. RESULTS: All patients tested positive to 0·1% DPGDA in pet., and two patients additionally to a 0·01% concentration. DPGDA was found in extracts of the Omnipod pumps brought by the patients. An Omnipod pump from an earlier batch contained tripropylene glycol diacrylate, IBOA, N,N-dimethylacrylamide, di(ethylene glycol)ethyl ether acrylate (DEGEA) but no DPGDA. One of the patients reacted positively to all of these allergens except DEGEA, which was not tested. CONCLUSIONS: When suspecting ACD to MDs, DPGDA at 0·1% in pet. should be tested. The contents of Omnipod have changed over time. Patch testing with updated test series and relevance assessment of positive reactions is a delicate task. Children, with lifelong use of MDs, risk contracting many allergies with potential cross-allergies. A question should be raised as to whether these low molecular weight acrylates should be used at all in devices constantly worn on the skin.

Continuous glucose monitoring systems give contact dermatitis in children and adults despite efforts of providing less 'allergy- prone' devices: investigation and advice hampered by insufficient material for optimized patch test investigations.

BACKGROUND: Medical devices are increasingly being reported to cause contact allergic dermatitis reactions. OBJECTIVE: Review of patients with diabetes type I referred for suspected allergic contact dermatitis to insulin pump or glucose sensor systems. METHOD: We have reviewed 11 referred diabetes mellitus patients investigated for allergic contact dermatitis reactions to medical devices and specifically Dexcom G6® . Extracts from the medical devices were analysed. RESULTS: The majority of patients was children, the majority had relevant allergies and particularly allergy to isobornyl acrylate which was also found in the glucose sensor system Dexcom G6® . CONCLUSIONS: The following case reports bring in focus the fact that patients sensitized through use of one medical device and being advised the use of another, or find another product for a while useful, are not by necessity free from future episodes of allergic contact dermatitis. The case reports emphasize the need for collaboration since it is impossible for even well-equipped laboratories to properly investigate the medical devices when information on the substances used in production is not uniform and complete and material to investigate are scarce. The importance of adequate patch test series and testing with own material and furthermore the importance to re-analyse medical devices and re-analyse test data are emphasized.

Prospective economic evaluation alongside the non-invasive ventilation trial.

OBJECTIVE: To determine the cost-effectiveness of nasal continuous positive pressure (nCPAP) compared with nasal intermittent positive pressure ventilation (NIPPV) in the context of the reported randomized clinical trial. STUDY DESIGN: Using patient-level data from the clinical trial, we undertook a prospectively planned economic evaluation. We measured costs, from a third-party payer perspective in all patients, and from a societal perspective in a subgroup with a time horizon through the earlier of discharge, death or 44 weeks post-menstrual age. RESULTS: From the third-party payer perspective, the mean cost of hospitalization per infant was statistically similar, $143 745 in the NIPPV group compared to $140 403 in the nCPAP group. Cost-effectiveness evaluation revealed a 61% probability that NIPPV is more expensive and less effective than nCPAP. Similar results were found in subgroup analysis from a societal perspective. CONCLUSION: In addition to being clinically equivalent, economic evaluation confirms that NIPPV, as employed in this trial, is also not economically favorable.

Stability of fragrance patch test preparations applied in test chambers.

BACKGROUND: Petrolatum patch test preparations are for practical reasons often applied in test chambers in advance, several hours or even days before the patient is tested. As many fragrance compounds are volatile it may be suspected that petrolatum preparations applied in test chambers are not stable over time. OBJECTIVES: To investigate the stability of petrolatum preparations of the seven chemically defined components in the fragrance mix (FM I) when stored in test chambers. METHODS: Samples of petrolatum preparations applied in test chambers stored at room temperature and in a refrigerator for between 4 and 144 h were analysed using liquid chromatographic methods. RESULTS: The concentration decreased by ≥ 20% within 8 h in four of seven preparations stored in Finn chambers at room temperature. When stored in a refrigerator only the preparation of cinnamal had decreased by ≥ 20% within 24 h. The stability of preparations of cinnamal stored in IQ chambers with a plastic cover was slightly better, but like the preparations applied in Finn chambers, the concentration decreased by ≥ 20% within 4 h at room temperature and within 24 h in a refrigerator. Cinnamal and cinnamyl alcohol were found to be more stable when analysed as ingredients in FM I compared with when analysed in individual preparations. CONCLUSIONS: Within a couple of hours several fragrance allergens evaporate from test chambers to an extent that may affect the outcome of the patch test. Application to the test chambers should be performed as close to the patch test occasion as possible and storage in a refrigerator is recommended.